Control Engineering Laboratory PORT-BASED MODELING · PDF fileControl Engineering Laboratory...

98
7/18/2005 Summerschool Bertinoro 17-23 July 2005 © P.C. Breedveld 1 Control Engineering Laboratory PORT-BASED MODELING OF DYNAMIC SYSTEMS: fundamental concepts and bond graphs PORT-BASED MODELING OF DYNAMIC SYSTEMS: fundamental concepts and bond graphs Peter Breedveld Peter Breedveld Control Engineering Laboratory, Faculty of Electrical Engineering, Mathematics and Computer Science University of Twente, Netherlands [email protected]

Transcript of Control Engineering Laboratory PORT-BASED MODELING · PDF fileControl Engineering Laboratory...

7182005 Summerschool Bertinoro17-23 July 2005

copy PC Breedveld1

Control Engineering Laboratory

PORT-BASED MODELING OF DYNAMIC SYSTEMS

fundamental concepts and bond graphs

PORT-BASED MODELING OF DYNAMIC SYSTEMS

fundamental concepts and bond graphs

Peter BreedveldPeter Breedveld

Control Engineering Laboratory Faculty of Electrical Engineering Mathematics and Computer ScienceUniversity of Twente Netherlands

pcbreedveldutwentenl

Some remarksSome remarks

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bullbull Role of concepts (lsquointellectrsquo multiple views)Role of concepts (lsquointellectrsquo multiple views)bullbull Ports from a historical energy point of viewPorts from a historical energy point of view

(energy states)(energy states)bullbull Focus on linear motion and fixed axis rotation Focus on linear motion and fixed axis rotation

simple configuration constraints no need for simple configuration constraints no need for abstract geometrical concepts (like in the rest of abstract geometrical concepts (like in the rest of the course)the course)

bullbull Separation between configuration state and energy Separation between configuration state and energy statestatestructures influence of kinematic constraintsstructures influence of kinematic constraints

General OutlineGeneral Outline

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bullbull Background and historyBackground and historybullbull Introduction to ports bonds and Introduction to ports bonds and

physical domainsphysical domainsbullbull Introduction to bond graph modelingIntroduction to bond graph modeling

causality domaincausality domain--independence etcindependence etc

Assumed prerequisitesAssumed prerequisites

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bullbull Some experience inSome experience inndashndash Block diagram modelsBlock diagram modelsndashndash Numerical simulation (methods)Numerical simulation (methods)ndashndash Linear and nonlinear analysisLinear and nonlinear analysisndashndash Basic physics (electrical circuits simple Basic physics (electrical circuits simple

rigid body mechanisms principles of rigid body mechanisms principles of thermodynamics etcthermodynamics etc

IntroductionIntroduction

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ndashndash Modular modeling (prevailing trend in Modular modeling (prevailing trend in modeling and simulation of complex modeling and simulation of complex physical systems)physical systems)

bullbull represented as a network interconnection of represented as a network interconnection of ideal elementsideal elements

ndashndash AdvantagesAdvantagesbullbull flexibilityflexibilitybullbull rere--usability of model partsusability of model partsbullbull physical insightphysical insightbullbull support for automated modelingsupport for automated modelingbullbull fundamental to systems and control theoryfundamental to systems and control theory

IntroductionIntroduction

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ndashndash DisadvantagesDisadvantagesbullbull equations of motion obtained directly from equations of motion obtained directly from

network modeling are oftennetwork modeling are oftenndashndash complicatedcomplicatedndashndash without apparent structurewithout apparent structurendashndash will easily contain will easily contain algebraic constraintsalgebraic constraints arising arising

from the interconnection of the subfrom the interconnection of the sub--systemssystemsbullbull no problem for digital simulation butno problem for digital simulation butbullbull may not be very wellmay not be very well--suited to analysis and suited to analysis and

control purposes (nonlinear systems)control purposes (nonlinear systems)

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

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bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

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Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

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BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Some remarksSome remarks

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bullbull Role of concepts (lsquointellectrsquo multiple views)Role of concepts (lsquointellectrsquo multiple views)bullbull Ports from a historical energy point of viewPorts from a historical energy point of view

(energy states)(energy states)bullbull Focus on linear motion and fixed axis rotation Focus on linear motion and fixed axis rotation

simple configuration constraints no need for simple configuration constraints no need for abstract geometrical concepts (like in the rest of abstract geometrical concepts (like in the rest of the course)the course)

bullbull Separation between configuration state and energy Separation between configuration state and energy statestatestructures influence of kinematic constraintsstructures influence of kinematic constraints

General OutlineGeneral Outline

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bullbull Background and historyBackground and historybullbull Introduction to ports bonds and Introduction to ports bonds and

physical domainsphysical domainsbullbull Introduction to bond graph modelingIntroduction to bond graph modeling

causality domaincausality domain--independence etcindependence etc

Assumed prerequisitesAssumed prerequisites

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bullbull Some experience inSome experience inndashndash Block diagram modelsBlock diagram modelsndashndash Numerical simulation (methods)Numerical simulation (methods)ndashndash Linear and nonlinear analysisLinear and nonlinear analysisndashndash Basic physics (electrical circuits simple Basic physics (electrical circuits simple

rigid body mechanisms principles of rigid body mechanisms principles of thermodynamics etcthermodynamics etc

IntroductionIntroduction

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ndashndash Modular modeling (prevailing trend in Modular modeling (prevailing trend in modeling and simulation of complex modeling and simulation of complex physical systems)physical systems)

bullbull represented as a network interconnection of represented as a network interconnection of ideal elementsideal elements

ndashndash AdvantagesAdvantagesbullbull flexibilityflexibilitybullbull rere--usability of model partsusability of model partsbullbull physical insightphysical insightbullbull support for automated modelingsupport for automated modelingbullbull fundamental to systems and control theoryfundamental to systems and control theory

IntroductionIntroduction

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ndashndash DisadvantagesDisadvantagesbullbull equations of motion obtained directly from equations of motion obtained directly from

network modeling are oftennetwork modeling are oftenndashndash complicatedcomplicatedndashndash without apparent structurewithout apparent structurendashndash will easily contain will easily contain algebraic constraintsalgebraic constraints arising arising

from the interconnection of the subfrom the interconnection of the sub--systemssystemsbullbull no problem for digital simulation butno problem for digital simulation butbullbull may not be very wellmay not be very well--suited to analysis and suited to analysis and

control purposes (nonlinear systems)control purposes (nonlinear systems)

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

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bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (14)

lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (18)

PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (20)

Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

General OutlineGeneral Outline

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (3)

bullbull Background and historyBackground and historybullbull Introduction to ports bonds and Introduction to ports bonds and

physical domainsphysical domainsbullbull Introduction to bond graph modelingIntroduction to bond graph modeling

causality domaincausality domain--independence etcindependence etc

Assumed prerequisitesAssumed prerequisites

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (4)

bullbull Some experience inSome experience inndashndash Block diagram modelsBlock diagram modelsndashndash Numerical simulation (methods)Numerical simulation (methods)ndashndash Linear and nonlinear analysisLinear and nonlinear analysisndashndash Basic physics (electrical circuits simple Basic physics (electrical circuits simple

rigid body mechanisms principles of rigid body mechanisms principles of thermodynamics etcthermodynamics etc

IntroductionIntroduction

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ndashndash Modular modeling (prevailing trend in Modular modeling (prevailing trend in modeling and simulation of complex modeling and simulation of complex physical systems)physical systems)

bullbull represented as a network interconnection of represented as a network interconnection of ideal elementsideal elements

ndashndash AdvantagesAdvantagesbullbull flexibilityflexibilitybullbull rere--usability of model partsusability of model partsbullbull physical insightphysical insightbullbull support for automated modelingsupport for automated modelingbullbull fundamental to systems and control theoryfundamental to systems and control theory

IntroductionIntroduction

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ndashndash DisadvantagesDisadvantagesbullbull equations of motion obtained directly from equations of motion obtained directly from

network modeling are oftennetwork modeling are oftenndashndash complicatedcomplicatedndashndash without apparent structurewithout apparent structurendashndash will easily contain will easily contain algebraic constraintsalgebraic constraints arising arising

from the interconnection of the subfrom the interconnection of the sub--systemssystemsbullbull no problem for digital simulation butno problem for digital simulation butbullbull may not be very wellmay not be very well--suited to analysis and suited to analysis and

control purposes (nonlinear systems)control purposes (nonlinear systems)

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

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bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (15)

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Assumed prerequisitesAssumed prerequisites

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (4)

bullbull Some experience inSome experience inndashndash Block diagram modelsBlock diagram modelsndashndash Numerical simulation (methods)Numerical simulation (methods)ndashndash Linear and nonlinear analysisLinear and nonlinear analysisndashndash Basic physics (electrical circuits simple Basic physics (electrical circuits simple

rigid body mechanisms principles of rigid body mechanisms principles of thermodynamics etcthermodynamics etc

IntroductionIntroduction

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ndashndash Modular modeling (prevailing trend in Modular modeling (prevailing trend in modeling and simulation of complex modeling and simulation of complex physical systems)physical systems)

bullbull represented as a network interconnection of represented as a network interconnection of ideal elementsideal elements

ndashndash AdvantagesAdvantagesbullbull flexibilityflexibilitybullbull rere--usability of model partsusability of model partsbullbull physical insightphysical insightbullbull support for automated modelingsupport for automated modelingbullbull fundamental to systems and control theoryfundamental to systems and control theory

IntroductionIntroduction

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ndashndash DisadvantagesDisadvantagesbullbull equations of motion obtained directly from equations of motion obtained directly from

network modeling are oftennetwork modeling are oftenndashndash complicatedcomplicatedndashndash without apparent structurewithout apparent structurendashndash will easily contain will easily contain algebraic constraintsalgebraic constraints arising arising

from the interconnection of the subfrom the interconnection of the sub--systemssystemsbullbull no problem for digital simulation butno problem for digital simulation butbullbull may not be very wellmay not be very well--suited to analysis and suited to analysis and

control purposes (nonlinear systems)control purposes (nonlinear systems)

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (8)

bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (11)

bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (14)

lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (15)

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

IntroductionIntroduction

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ndashndash Modular modeling (prevailing trend in Modular modeling (prevailing trend in modeling and simulation of complex modeling and simulation of complex physical systems)physical systems)

bullbull represented as a network interconnection of represented as a network interconnection of ideal elementsideal elements

ndashndash AdvantagesAdvantagesbullbull flexibilityflexibilitybullbull rere--usability of model partsusability of model partsbullbull physical insightphysical insightbullbull support for automated modelingsupport for automated modelingbullbull fundamental to systems and control theoryfundamental to systems and control theory

IntroductionIntroduction

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (6)

ndashndash DisadvantagesDisadvantagesbullbull equations of motion obtained directly from equations of motion obtained directly from

network modeling are oftennetwork modeling are oftenndashndash complicatedcomplicatedndashndash without apparent structurewithout apparent structurendashndash will easily contain will easily contain algebraic constraintsalgebraic constraints arising arising

from the interconnection of the subfrom the interconnection of the sub--systemssystemsbullbull no problem for digital simulation butno problem for digital simulation butbullbull may not be very wellmay not be very well--suited to analysis and suited to analysis and

control purposes (nonlinear systems)control purposes (nonlinear systems)

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (8)

bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

IntroductionIntroduction

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ndashndash DisadvantagesDisadvantagesbullbull equations of motion obtained directly from equations of motion obtained directly from

network modeling are oftennetwork modeling are oftenndashndash complicatedcomplicatedndashndash without apparent structurewithout apparent structurendashndash will easily contain will easily contain algebraic constraintsalgebraic constraints arising arising

from the interconnection of the subfrom the interconnection of the sub--systemssystemsbullbull no problem for digital simulation butno problem for digital simulation butbullbull may not be very wellmay not be very well--suited to analysis and suited to analysis and

control purposes (nonlinear systems)control purposes (nonlinear systems)

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

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bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Course objectivesCourse objectives

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ndashndash particular type of network modeling viz particular type of network modeling viz portport--based modelingbased modeling

bullbull subsub--systems are interacting through power systems are interacting through power exchange represented by pairs of exchange represented by pairs of conjugated variablesconjugated variables

bullbull unified way to deal with systems from unified way to deal with systems from different physical domains (eg mechanical different physical domains (eg mechanical and electrical) and electrical)

bullbull resulting systems of equations possess an resulting systems of equations possess an underlying generalized Hamiltonian underlying generalized Hamiltonian structure leading to the geometric notion of structure leading to the geometric notion of a porta port--Hamiltonian systemHamiltonian system

Course objectivesCourse objectives

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (8)

bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (11)

bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (12)

bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (13)

lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (14)

lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (15)

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (16)

Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (18)

PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Course objectivesCourse objectives

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bullbull exploiting the underlying Hamiltonian exploiting the underlying Hamiltonian structure offers many possibilities forstructure offers many possibilities for

ndashndash analysisanalysisndashndash simulationsimulationndashndash controlcontrol

of complex physical systemsof complex physical systemsbullbull illustrated in variety of application areasillustrated in variety of application areasbullbull possible extension to classes of possible extension to classes of

distributeddistributed--parameter systemsparameter systems

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

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AppetizerNewton cradle example

AppetizerNewton cradle example

bullbull ExperimentExperiment

bullbull 2020--sim sim demdemoobullbull AnimationAnimation

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Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (10)

Dual role exampleFalling and bouncing object

Dual role exampleFalling and bouncing object

bullbull generally considered as conceptually generally considered as conceptually complexcomplexndashndash switching models switching models reinitializationreinitialization timing timingndashndash energy bookkeepingenergy bookkeepingndashndash prone to sign errorsprone to sign errors

bullbull portport--based approach with explicit based approach with explicit structure allows conceptually simple structure allows conceptually simple solutionsolution

AimAim

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bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (13)

lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (14)

lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (15)

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (16)

Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (18)

PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

AimAim

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (11)

bullbull System theoretic approach to physical system dynamics System theoretic approach to physical system dynamics based onbased onndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull shown how as a resultshown how as a resultndashndash variables and relations describing physical systems may be variables and relations describing physical systems may be

classifiedclassifiedndashndash models may be organized as (lsquoportmodels may be organized as (lsquoport--based approachrsquo)based approachrsquo)

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a a

generalized networkgeneralized networkndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy gy

and entropyand entropybullbull special attentionspecial attention

ndashndash role of analogiesrole of analogiesndashndash analogue behavioranalogue behavior

Fundamental issuesFundamental issues

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bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Fundamental issuesFundamental issues

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (12)

bull introduction amp some philosophybull Why physical systems modelingbull What is physical systems modelingbull Context of explanation (focus of engineering

physics) versus justification (focus of math)bull elements and components theory buildingbull synthesis between classical approaches

bull choice of variablesndashndash mechanical versus thermodynamic mechanical versus thermodynamic

frameworkframework

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lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (14)

lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (13)

lsquoWhyrsquoThree-world meta-model

lsquoWhyrsquoThree-world meta-model

bullbull Real worldReal world (assuming existence of (assuming existence of lsquolsquoobjectiveobjectiversquorsquoenvironmentenvironmentrsquorsquo))

bullbull Conceptual worldConceptual world (in our brain)(in our brain)bullbull lsquolsquoPaperPaperrsquorsquo worldworld including electronically stored including electronically stored

datadata

ndashndash Only invia the paper worldOnly invia the paper worldbullbull CommunicationCommunicationbullbull SupportSupportbullbull SystematizationSystematization

ndashndash exchangeable abstractionsconcepts gtgtgtexchangeable abstractionsconcepts gtgtgtndashndash importance of importance of symbolssymbols amp amp notation notation (representation)(representation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (14)

lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (15)

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (16)

Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (18)

PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

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lsquoWhyrsquoAre physical concepts lsquorealrsquo

lsquoWhyrsquoAre physical concepts lsquorealrsquo

bullbull For exampleFor examplendashndash energy time momentum causalityhellipenergy time momentum causalityhellip

bullbull In a context of In a context of justificationjustification NONObullbull In a context of In a context of discoverydiscoveryexplanationexplanation

YES YES but rather lsquoreally usefulrsquo than but rather lsquoreally usefulrsquo than just lsquorealrsquojust lsquorealrsquo

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lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (15)

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

lsquoWhyrsquoThe useless lsquoquest for truthrsquo

bullbull A model is necessarily A model is necessarily incompleteincompletelsquolsquoall models are wrongall models are wrongrsquorsquo but but lsquolsquotruthtruthrsquorsquo is is notnot

what countswhat countsbullbull The issue is whether a model is The issue is whether a model is

competentcompetent (to solve a problem in a (to solve a problem in a given given problem contextproblem context in the most in the most generic sense of the word)generic sense of the word)

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (31)

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (33)

bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (36)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

What is a modelWhat is a model

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Some sort of abstraction Some sort of abstraction (in the (in the lsquolsquopaperpaperrsquorsquo world)world) that enablesthat enablesbullbull insight insight in in the real world counterpartthe real world counterpartbullbull communicationcommunication about about the real world counterpartthe real world counterpartbullbull observationobservation of of the real world counterpartthe real world counterpartbullbull troubleshootingtroubleshooting of of the real world counterpartthe real world counterpartbullbull designdesign of new aspects related to the real world counterpartof new aspects related to the real world counterpartbullbull modificationsmodifications of of the real world counterpartthe real world counterpartbullbull lsquolsquoexplanationexplanationrsquorsquo of of functionalityfunctionality of the real world counterpartof the real world counterpartbullbull measurementmeasurement of of the real world counterpartthe real world counterpart

but most importantly that is but most importantly that is bullbull competentcompetent to solve a given problem and make decisions to solve a given problem and make decisions

related to the real worldrelated to the real world

ModelingModeling

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bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (18)

PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

ModelingModeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (17)

bull Given a specific problem context the decision process to obtain a competent model to solve this problem

bull Approaches between two extremesndashndash a priori knowledgea priori knowledgendashndash lsquolsquoblack boxblack boxrsquorsquo (also an axiomatic concept with a priori (also an axiomatic concept with a priori

assumptions)assumptions)bullbull concept concept lsquolsquoinputinputrsquorsquo implicitly contains model of imposing some implicitly contains model of imposing some

action with negligible back effect (action with negligible back effect (lsquolsquohigh input impedancehigh input impedancersquorsquo))bullbull concept concept lsquolsquooutputoutputrsquorsquo implicitly contains model of measurement implicitly contains model of measurement

with negligible effect on the system being observed (with negligible effect on the system being observed (lsquolsquolow low output impedanceoutput impedancersquorsquo))

bullbull after a competent inputafter a competent input--output relation is found it is not output relation is found it is not open for modifications or physical interpretationopen for modifications or physical interpretation

lsquoSpecialrsquo stateslsquoSpecialrsquo states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (18)

PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (19)

bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

lsquoSpecialrsquo stateslsquoSpecialrsquo states

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PositiondisplacementPositiondisplacementbullbull has a has a dualdual naturenature

ndashndash energyenergy state (related to a conservation or symmetry principle state (related to a conservation or symmetry principle like all other states)like all other states)

ndashndash configurationconfiguration statestatebullbull does does notnot transform as a transform as a tensortensorMatterMatterbullbull convectsconvects all matterall matter--bound properties (not volume)bound properties (not volume)bullbull conjugate intensity depends on other intensitiesconjugate intensity depends on other intensitiesbullbull boundary criterionboundary criterionVolumeVolumebullbull boundary criterionboundary criterionEntropyEntropybullbull can be lsquolocallyrsquo can be lsquolocallyrsquo producedproduced (only lsquolocallyrsquo conserved) (only lsquolocallyrsquo conserved)

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Model representationModel representation

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bullbull model model representationrepresentationndashndash symbols used to representsymbols used to represent

bullbull the the conceptsconcepts being usedbeing usedbullbull (the structure of) their (the structure of) their relationsrelations (interconnection)(interconnection)

bullbull model model manipulationmanipulation (as opposed to modeling) (as opposed to modeling) ndashndash transformation to transformation to differentdifferent representations (including representations (including

the the lsquolsquosolutionsolutionrsquorsquo) to) tobullbull increase insightincrease insightbullbull draw conclusions etcdraw conclusions etc

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Role of representationsRole of representations

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Process timeProcess timeversusversus

processprocessinging timetime

A

A

A

A

A

T

T

T

T

T

a

b

c

d

e

x1

x2

x3

x4

x5

SequentialSequential

A

T

T

A

x

t

x1 x5x4

x3x2

SimultaneousSimultaneous

What are we trying to describeWhat are we trying to describe

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bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

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bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

What are we trying to describeWhat are we trying to describe

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (21)

bullbull (dynamic) behavior(dynamic) behaviorbullbull engineering systemsengineering systemsbullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic models of systems that obey models of systems that obey basic basic principlesprinciples of of macroscopicmacroscopic physicsphysics

bullbull energyenergy conservationconservation ((lsquolsquofirst lawfirst lawrsquorsquo))bullbull positive positive entropyentropy productionproduction ((lsquolsquosecond lawsecond lawrsquorsquo))

bullbull that describe the temporal trajectory of the that describe the temporal trajectory of the common physical propertiescommon physical propertiesndashndash mechanical (incl hydraulic and pneumatic) mechanical (incl hydraulic and pneumatic)

electrical magnetic electrical magnetic chemical material thermalchemical material thermal etc gtgtgt multidomainetc gtgtgt multidomain

ndashndash configurationconfiguration

Physical systems modelingPhysical systems modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (22)

bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (33)

bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Physical systems modelingPhysical systems modeling

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bullbull all concepts used in the model are or have a direct relation all concepts used in the model are or have a direct relation to to physically relevant conceptsphysically relevant concepts (use of a priori knowledge)(use of a priori knowledge)

bullbull physicalphysical relationsrelations are maintained as much as possibleare maintained as much as possiblebullbull herein constrained to (for sake of herein constrained to (for sake of lsquolsquosimplicitysimplicityrsquorsquo))

ndashndash deterministicdeterministic mathematical models of mathematical models of macroscopicmacroscopic systems systems thatthat

bullbull obey obey basic principlesbasic principles of macroscopic physicsof macroscopic physicsndashndash energyenergy conservationconservationndashndash positive positive entropyentropy productionproduction

bullbull describe the describe the behaviorbehavior in time of the common physical propertiesin time of the common physical propertiesndashndash mechanical (incl hydraulic and pneumatic)mechanical (incl hydraulic and pneumatic)ndashndash electricalelectricalndashndash magneticmagneticndashndash chemicalchemicalndashndash materialmaterial

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

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concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

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bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

time amp uncertaintytime amp uncertainty

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (23)

bullbull timetimendashndash derivedderived measure for lsquomeasure for lsquoregularityregularityrsquo based on rsquo based on

counting lsquoticksrsquo of a lsquotimecounting lsquoticksrsquo of a lsquotime--basersquo based on basersquo based on repetitive behaviorrepetitive behavior requiringrequiring statestate and and change change (in (in order to be able to count)order to be able to count)

ndashndash within the smallest unit used necessarily within the smallest unit used necessarily uncertainty uncertainty

bullbull cf Heisenberg ur for displacement (= elastic state cf Heisenberg ur for displacement (= elastic state kinetic state of change) and momentum (= elastic state kinetic state of change) and momentum (= elastic state of change kinetic state)of change kinetic state)

ndashndash dialectic conceptsdialectic concepts

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (31)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (36)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (24)

concepts oflsquostatersquo amp lsquochangersquo

concepts oflsquostatersquo amp lsquochangersquo

bullbull dialecticdialectic fundamental conceptsfundamental conceptsbullbull basis for any basis for any dynamicdynamic model (more model (more

than time)than time)bullbull within a within a context of discoverycontext of discovery a shift to a shift to

spacespace--time is understandable and time is understandable and useful like the shift from positionuseful like the shift from position--momentum in Hamiltonian mechanics to momentum in Hamiltonian mechanics to positionposition--velocity in Lagrangian velocity in Lagrangian mechanicsmechanics

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Contents of the sequelContents of the sequel

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (25)

bullbull Modeling pitfallsModeling pitfallsbullbull PortPort--based modeling based modeling bullbull Basic Concepts (ports bonds)Basic Concepts (ports bonds)bullbull Dynamic conjugation (effort flow)Dynamic conjugation (effort flow)bullbull Multidomain modeling and the role of Multidomain modeling and the role of

energyenergybullbull (Computational) Causality(Computational) Causality

Modeling pitfallsModeling pitfalls

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (26)

bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Modeling pitfallsModeling pitfalls

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bullbull lsquolsquoEvery model is wrongrsquoEvery model is wrongrsquo

bullbull Model depends on problem contextModel depends on problem context

bullbull Competent modelsCompetent models

bullbull Analogies are not identitiesAnalogies are not identities

bullbull Avoid implicit assumptionsAvoid implicit assumptions

bullbull Avoid model extrapolationAvoid model extrapolation

bullbull Confusion of components with elementsConfusion of components with elements

Port-based modelingPort-based modeling

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bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Port-based modelingPort-based modeling

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (27)

bullbull multidomainmultidomain approachapproachndashndash lsquomechatronicsrsquo (and beyond)lsquomechatronicsrsquo (and beyond)

bullbull multiple viewmultiple view approach other graphical approach other graphical representations iconic diagrams (linear representations iconic diagrams (linear graphs) block diagrams graphs) block diagrams bond graphsbond graphs etc and etc and equationsequations

bullbull domain independentdomain independent notation using portsnotation using portsndashndash bond graphs (amp some other benefitshellip)bond graphs (amp some other benefitshellip)

bullbull portport--basedbased approachapproachndashndash underlying structure of underlying structure of 2020--simsim ideal tool for ideal tool for

demonstrationdemonstrationbullbull what are what are portsports and what are and what are bond graphsbond graphs

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Physical components versus ideal elements

Physical components versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

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Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

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BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (28)

Physical components versus ideal elements

Physical components versus ideal elements

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Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

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Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

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BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (29)

Physical component versus ideal elements

Physical component versus ideal elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (30)

Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (31)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (33)

bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (36)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

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Physical component versus ideal elements

Physical component versus ideal elements

Component mounterComponent mounter

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (32)

Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (33)

bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Component mounterComponent mounter

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (33)

bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (34)

bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (36)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

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Physical components versus conceptual elements

Physical components versus conceptual elements

physical componentphysical componentpiece of rubber hosepiece of rubber hose

dominant behaviordominant behaviorbullbullwhen falling when falling ideal massideal massbullbullwhen pulling load when pulling load ideal springideal springbullbullfor vibration isolation for vibration isolation ideal resistorideal resistorbullbulletcetc

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (35)

Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

lsquoParasiticrsquo elementslsquoParasiticrsquo elements

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bullbull Next to dominant behaviorNext to dominant behavior

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

In engineering modelsIn engineering models

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bullbull Avoid implicit assumptions eg aboutAvoid implicit assumptions eg aboutndashndash problem contextproblem context

ndashndash referencereference

ndashndash orientationorientation

ndashndash coordinatescoordinates

ndashndash metricmetric

ndashndash lsquonegligiblersquo phenomena etclsquonegligiblersquo phenomena etc

bullbull Avoid model extrapolationAvoid model extrapolationndashndash danger of ignoring earlier assumptionsdanger of ignoring earlier assumptions

bullbull Focus at competence not lsquotruthrsquoFocus at competence not lsquotruthrsquo

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

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Intuitive introduction of the lsquoportrsquo concept

Intuitive introduction of the lsquoportrsquo concept

ideal ideal motormotor

J

ideal ideal inertiainertiaideal ideal

transmissiontransmission

ideal current ideal current sourcesource

P

potentiometerpotentiometer

Dominant behaviorDominant behavior

(not necessarily competent in each context)(not necessarily competent in each context)

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Simple modelSimple model

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (37)

Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

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Addition of relevant parasitic behavior

Addition of relevant parasitic behavior

Depending on Depending on problem problem contextcontext

Polymorphic Polymorphic modelingmodeling

What are portsWhat are ports

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MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

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C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

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Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

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BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

What are portsWhat are ports

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (38)

MECH

J

ii∆∆uu11

ii ii

∆∆uu22 ∆∆uu33∆∆TT22 ∆∆TT33

ωω ωω

PP ==∆∆uusdotsdot ii(power)(power)

PP ==∆∆TTsdotsdotωω(power)(power)

ii∆∆uu44

∆∆TT11

ωω

electrical portselectrical ports

mechanical portsmechanical ports

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Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

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Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (39)

Comparison with familiar model views

Comparison with familiar model views

Iconic diagramsIconic diagrams(lsquoideal physical modelsrsquo)(lsquoideal physical modelsrsquo)

R L

C

R

K=1CFext

Usource

i v

F m

electricalelectrical mechanicalmechanical

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (40)

Port-based but domain dependentPortPort--based but based but domain dependentdomain dependent

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (42)

bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Iconic diagram symbolsIconic diagram symbols

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (41)

C-type storage

I -type storage

(M)R (dissipation

irreversible transduction)

Se (effort source)

Sf (flow source)

TF (transformer)

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Iconic diagramsIconic diagrams

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bullbull Icons do not (always) represent Icons do not (always) represent physical structurephysical structure

1

i

2020--simsim

iconicon

TF (transformer)TF (transformer)

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Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (43)

Common block diagram models

Common block diagram models

R L

C

R

K=1CFext

Usource

i v

F m

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Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

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Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

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BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (44)

Common block diagram models

Common block diagram models

Note not all signals Note not all signals are physically are physically

meaningful variablesmeaningful variables

Ports in iconic diagramsPorts in iconic diagrams

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R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (45)

R L

C

R

K=1CFext

Usource

i v

F m

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Ports in iconic diagramsPorts in iconic diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (46)

R L

C

R

K=1C

Fext

Usource

i

v

F

m

Ports in block diagramsPorts in block diagrams

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (47)

Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (48)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Ports in block diagramsPorts in block diagrams

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Note each signal is a physically Note each signal is a physically meaningful variablemeaningful variable

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

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Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

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I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

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Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

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BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Structure as multiportStructure as multiport

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Different formsDifferent forms

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Different formsDifferent forms

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Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (49)

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Different formsDifferent forms

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (50)

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (51)

Source

Coil

Capacitor

Resistor

Source

Mass

Spring

Damper

Domain dependent

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Compact amp domain independentCompact amp domain independent

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (52)

I

C

R

Se

I

C

R

1Se

Domain independent

1

Structure explicitlyStructure explicitly

representedrepresented

as multiportas multiport

JUNCTIONJUNCTION

Ports in bond graph viewPorts in bond graph view

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C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Ports in bond graph viewPorts in bond graph view

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (53)

C

R

Se

I

1

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Bond graphsBond graphs

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (54)

Inventor (MIT 1959) Prof Henry M Paynter (1923-2002)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (55)

Analog simulation withOP-AMPS

Analog simulation withOP-AMPS

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (57)

bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (56)

BondsBonds

Energy exchange = powerEnergy exchange = power

Storage of kinetic energyStorage of kinetic energyStorage of elastic energyStorage of elastic energy

C ICompact notationCompact notation

bullbullTerminology and notation induced by chemical bondsTerminology and notation induced by chemical bonds

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Ports and power bondsPorts and power bonds

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bullbull (power) bond connecting two elements (power) bond connecting two elements via (power) ports (Harold Wheeler via (power) ports (Harold Wheeler 1949)1949)

mass-spring systemmass-spring system

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Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

mass-spring systemmass-spring system

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (58)

Dynamic conjugationDynamic conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (59)

bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Dynamic conjugationDynamic conjugation

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bullbull Between signals of bilateral signal Between signals of bilateral signal flow of relationflow of relationndashndash rate of change lsquoflowrsquo (zero in rate of change lsquoflowrsquo (zero in

equilibrium)equilibrium)bullbull eg molar rate during diffusioneg molar rate during diffusion

ndashndash equilibrium determining variable lsquoeffortrsquoequilibrium determining variable lsquoeffortrsquobullbull eg concentrationeg concentration

Power conjugationPower conjugation

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= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

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Conjugate variables amp corresponding statesConjugate variables amp corresponding states

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Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Power conjugationPower conjugation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (60)

= special case of dynamic conjugation = special case of dynamic conjugation ndashndash lsquoeffortrsquo and lsquoflowrsquo relate to lsquoeffortrsquo and lsquoflowrsquo relate to powerpowerndashndash functional relation is commonly a functional relation is commonly a productproduct

ndashndash sumsum in case of scattering variablesin case of scattering variables

part part= = + = +

part part

part= =

partpart

= =part

sum sum sum sumddd

d d d

d effort

d

d flow

d

jii i j j

i ji j i j

ji j

i

ii j

j

pqE E EP e f e f

t q t p t

pEe e

q t

q Ef f

t p

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (61)

Conjugate variables amp corresponding statesConjugate variables amp corresponding states

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (62)

Basic dynamic behaviorsamp mnemonic codes

Basic dynamic behaviorsamp mnemonic codes

bullbull StorageStorage (reversible)(reversible)ndashndash CC I (qI (q--type and ptype and p--type storage) type storage)

bullbull Irreversible transformationIrreversible transformation (lsquodissipationrsquo)(lsquodissipationrsquo)ndashndash (M)(M)RR(S)(S)

bullbull DistributionDistributionndashndash 00--junction junction 11--junctionjunction

bullbull Supply and demandSupply and demandndashndash (M)(M)SeSe ( (M)M)SfSf

bullbull Reversible transformationReversible transformationndashndash (M)(M)TFTF (M) (M)GYGY

bullbull gtgt gtgt 9 basic elements9 basic elements

Orientation conventionsOrientation conventions

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bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

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Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Orientation conventionsOrientation conventions

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (63)

bullbull 11--ports into most elements (R C I) except ports into most elements (R C I) except sources (Se sources (Se SfSf))

bullbull 22--port transducers 1 in 1 outport transducers 1 in 1 outbullbull junction structure elements arbitraryjunction structure elements arbitrarybullbull multiport generalizations same as simple formmultiport generalizations same as simple formbullbull MOST IMPORTANT obeying grammar rules MOST IMPORTANT obeying grammar rules

minimizes sign errorsminimizes sign errors

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Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

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copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

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C

R

Se

I

1

Back to the exampleBack to the example

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C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

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Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (64)

Convention on effort and flow positions

Convention on effort and flow positions

Basic one-port elementsBasic one-port elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (65)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

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second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

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bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

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bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

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bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

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daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Basic one-port elementsBasic one-port elements

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Basic two- and multiport elements

Basic two- and multiport elements

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Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

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Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

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bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

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Arbitrary causalityArbitrary causality

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Causality assignmentCausality assignment

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Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (66)

Basic two- and multiport elements

Basic two- and multiport elements

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

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Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

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Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

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Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

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System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

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bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (67)

Constitutive relations not necessarily linear

Constitutive relations not necessarily linear

eg zener diodeeg zener diodedominant behaviordominant behavior

irreversible irreversible transduction transduction (resistor)(resistor)

with nonlinear with nonlinear constitutive relationconstitutive relation

R

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (68)

Other form of non-linearityModulation

Other form of non-linearityModulation

eg modulation of a transducereg modulation of a transducer iconic diagram (IPM)iconic diagram (IPM)

MR

capstancapstan

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Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

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orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

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Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

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Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

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Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

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bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (69)

Bilateral signal flow (computational causality)

Bilateral signal flow (computational causality)

2 possibilities2 possibilities

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

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bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

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SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

NotationNotation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (70)

Causal strokeCausal stroke

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (71)

C

R

Se

I

1

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Back to the exampleBack to the example

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (72)

C

R

Se

I

1

2020--sim demosim demo

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Causal port propertiesCausal port properties

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (73)

bullbull FixedFixed causalitycausality

bullbull PreferredPreferred (integral) causality(integral) causality

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

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Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

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Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

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bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Causal constraintsCausal constraints

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (74)

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Arbitrary causalityArbitrary causality

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (75)

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Causality assignmentCausality assignment

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (76)

Algorithmic (SCAP)Algorithmic (SCAP)ndashndash 1) fixed causal ports with propagation via 1) fixed causal ports with propagation via

constraintsconstraintscausal lsquoconflictrsquo causal lsquoconflictrsquo lsquoilllsquoill--posednessposednessrsquorsquo

ndashndash 2) preferred causal ports with 2) preferred causal ports with propagation via constraintspropagation via constraintscausal lsquoconflictrsquo causal lsquoconflictrsquo dependent state(s)dependent state(s)

ndashndash 3) choice of arbitrary causal port with 3) choice of arbitrary causal port with propagation via constraintspropagation via constraintsmeans existence of means existence of algebraic algebraic loop(sloop(s))

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

ExampleExample

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (77)

Se GY

II

R

1

R

1

2nd order loop2nd order loop

1st order loop1st order loop1st order loop1st order loop

bullbullImportant modeling feedbackImportant modeling feedback

bullbullAutomatic in 20Automatic in 20--simsim

bullbullVisible in bond graph causalityVisible in bond graph causality

bullbulllsquoHiddenrsquo in case of iconic diagramslsquoHiddenrsquo in case of iconic diagrams

J

u

i u

i

u

i

u

i

u

i

T

ω

T

ω

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Positive orientationPositive orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (78)

orientationorientation NOT THE SAME AS NOT THE SAME AS directiondirection

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Causality does NOT affect orientationCausality does NOT affect orientation

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (79)

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Basic form of physical modelsBasic form of physical models

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (80)

second lsquolawrsquoirreversible

transformation

boundaryaddition

structureconstraint relationsdistribution reversible

transformationtransport

first lsquolawrsquoconservation lsquolawsrsquo

storage

interfaces and structurehave to satisfy basic laws in degenerate way

storage = 0 production = 0 Basic lsquolawsrsquo

constitutive relationsdetermine particular occurrence (instantiation)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (81)

Thermodynamic approachThermodynamic approach

Energy balanceEnergy balance

for the totalfor the total

systemsystem

Gibbsrsquo relation Gibbsrsquo relation (Energy (Energy

lsquobalancersquo of the lsquobalancersquo of the reversible part)reversible part)

bullbull Difference is used to find the entropy productionDifference is used to find the entropy production

bullbull Power continuous structure not made explicitPower continuous structure not made explicitexcept for instantaneous except for instantaneous CarnotCarnot engines (1engines (1--junction for entropy flow)junction for entropy flow)

System boundarySystem boundary

Irreversible Irreversible thermodynamics of thermodynamics of lsquoforcesrsquo and lsquofluxesrsquo lsquoforcesrsquo and lsquofluxesrsquo (irreversible part)(irreversible part)

GJSGJSGJS

Power continuous Power continuous junction structurejunction structure

Structure is Structure is conceptualconceptual

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (82)

Mechanical versus Thermodynamic framework

Mechanical versus Thermodynamic framework

Split domains (Split domains (thermtherm) and couple by SGY ) and couple by SGY (mech)(mech)

CC--SGYSGY--CC

Only relaxation Only relaxation behavior Cbehavior C--RR

Oscillatory behavior Oscillatory behavior (damped) C(damped) C--I(I(--R)R)

OneOne type of storagetype of storageTwoTwo types of storagetypes of storageThermodynamicsThermodynamicsMechanicsMechanics

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Symplectic gyratorSymplectic gyrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (83)

bullbull Unit gyratorUnit gyrator

bullbull SGYSGY

bullbull Multiport

r = 1GY0 0C C

SGY0 0C C

0 -1+1 0

C11 C12C12 C22 SGYC 0Multiport

2020--sim demosim demo

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Symplectic GYratorSymplectic GYrator

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (84)

bullbull Mechanical (Mechanical (xxpp))

ndashndash Only in Only in inertialinertial frames (Newtons 2nd law)frames (Newtons 2nd law)

bullbull Electrical network (Electrical network (qqλλ))

ndashndash Only Only quasiquasi--stationarystationary (non(non--radiating)radiating)

SGY0 0C C

SGY0 0C C

part=

partpotEex

dd

=potxft

part=

partkinEep

dd

=kinpft

dd

= minuspFt

=potf v

=pote F=kine v

dd

= minuspFt

λpart

=partmagEe

ddλ

=magft

ddλ

minus = ut

=mage i

dd

=elecqft

=elecf i

part=

partelecEeq=elece u

ddλ

minus = ut

=mage i

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Unit gyrator (SGY) as lsquodualizerrsquoUnit gyrator (SGY) as lsquodualizerrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (85)

Port equivalentPort equivalent Port equivalentPort equivalentOriginalOriginal OriginalOriginal

C1 SGY 1 I

R1 SGY 1 R

1 SGY TF SGY 0 1 TF 0

SGY GY SGY 1 1 GY 1

SGY1

1 TF 0SGY1

1 GY 1

0GY

TF 1

1 0SGY SGY1

0

SGY

1

1

0

1 0

0

SGY SGY0

1

SGY

1 0

1

1

0

0

Se SGY 1

0Sf SGY

Sf 1

Se 0

I 0 C0 SGY

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (86)

Basic model structure(generalized bond graph)

Basic model structure(generalized bond graph)

AntiAnti--reciprocal reciprocal part (generalized part (generalized

gyrator)gyrator)

Weighted Junction Weighted Junction Structure Structure

(reciprocal)(reciprocal)

Simple Junction Simple Junction Structure (generalized Structure (generalized

KirchhoffKirchhoff laws)laws)

Weighted part (generalized Weighted part (generalized transformer)transformer)

Generalized Junction Generalized Junction Structure (power Structure (power

continuous)continuous)Boundary conditionsBoundary conditions

(sources)(sources)

Energy storageEnergy storageIrreversible Irreversible transformationtransformation

(entropy production)(entropy production)

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (87)

Mechanical framework of variables

Mechanical framework of variables

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (88)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

q f t= int d

q i t= int d

λ = intu td

int= tSS f d

int= tNN f d

f flow

eeffort generalized state

electric icurrent

uvoltage charge

magnetic uvoltage

icurrent magnetic flux linkage

thermal Ttemperature

fSentropy flow

entropy

chemical microchemical potential

fNmolar flow

number of moles

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (89)

Generalized thermodynamic framework of variables

Generalized thermodynamic framework of variables

f flow

eeffort generalized state

elasticpotential translation

vvelocity

Fforce displacement

kinetic translation

Fforce

vvelocity momentum

elasticpotential rotation

ωangular velocity

Ttorque angular displacement

kinetic rotation Ttorque

ωangularvelocity

angularmomentum

elastic hydraulic ϕvolume flow

ppressure

volume

kinetic hydraulic ppressure

ϕvolume flow

momentum of a flow tube

θ = int ωdt

b T t= int d

V t= int ϕd

dp tΓ = int

p F t= int d

x v t= int d

q f t= int d

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Energy as starting pointEnergy as starting point

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (90)

bullbull EnergyEnergyndashndashndashndash Homogeneous function of set of state variablesHomogeneous function of set of state variables

bullbull In (lsquogeneralizedrsquo) In (lsquogeneralizedrsquo) mechanics mechanics Hamiltonian Hamiltonianndashndash

bullbull In In thermodynamicsthermodynamics of lsquosimplersquo systems of lsquosimplersquo systems internal energyinternal energyndashndashndashndash more speciesmore species

( ) ( )1 i nE E q E q q q= =

( ) ( )1 1 i k i kE H q p H q q q p p p= =

( ) ( ) E U q U V S N= =

( ) ( )( )( )

1

1 1

i m

i m

E U q U V S N

U V S N N N

U V S N N N Nminus

= = =

= =

=

( ) ( )( )

2

2

i n

i n

U U q U S q q q

S S U q q q

= =

=

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (91)

Configuration influence on energetic structure

Configuration influence on energetic structure

bullbull can become an additional energy state geometric can become an additional energy state geometric parameter in storage relation results in a forceparameter in storage relation results in a force

ndashndash examples LVDT electret microphone relay examples LVDT electret microphone relay (ideal) gas(ideal) gasetc (MP C)etc (MP C)

ndashndash cycles allow transductioncycles allow transductionndashndash changes of causality correspond to Legendre transforms changes of causality correspond to Legendre transforms

(relation to dissipation)(relation to dissipation)bullbull can modulate an energy relationcan modulate an energy relation

ndashndash examples crankexamples crank--slider slider mechanismmechanism etc (MTF) etc (MTF)bullbull can switch a contact (behavior) can switch a contact (behavior)

( ) ( )

E q xF q x

xpart

=part

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Modulated capacitorModulated capacitor

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (92)

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

System (boundary) definitionSystem (boundary) definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (93)

bullbull Open (thermodynamic) systemsOpen (thermodynamic) systemsbullbull ddNN = 0= 0 lsquo lsquoLagrangianLagrangian coordinatesrsquocoordinatesrsquo

N not a stateN not a statebullbull ddVV = 0= 0 lsquo lsquoEulerianEulerian coordinatesrsquocoordinatesrsquo

V not a stateV not a statebullbull Almost always Almost always mixed boundariesmixed boundaries

NN and and VV remain statesremain statesbullbull NetworkNetwork globally globally EulerianEulerian locally locally

LagrangianLagrangian (eg network of tubes)(eg network of tubes)

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

lsquoClassical network casersquolsquoClassical network casersquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (94)

bullbull Both Both NN and and V V ndashndash constantconstantndashndash NOT CONSIDERED STATES but NOT CONSIDERED STATES but parametersparameters

bullbull As a resultAs a resultndashndash energy function not necessarily first order energy function not necessarily first order

homogenoushomogenousndashndash no dependency between storage port efforts no dependency between storage port efforts

(no generalized Gibbs(no generalized Gibbs--DuhemDuhem equation)equation)ndashndash no clear distinction between intensive and no clear distinction between intensive and

extensive descriptionextensive description

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

If not a networkIf not a network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (95)

bullbull Globally Globally LagrangianLagrangian and locally and locally EulerianEulerian possiblepossible

bullbull Example balloonExample balloon

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

Part of a tube networkPart of a tube network

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (96)

daxialV=0(V not a convected property)daxial Nne0

dradialN=0dradial Vne0(flexible tube local changes)

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

System boundary definitionSystem boundary definition

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (97)

bullbull Mechanical system of masses Mechanical system of masses springs dampers etc (network)springs dampers etc (network)ndashndash globally globally EulerianEulerian coordinatescoordinates

bullbull because the network (topology) of spatial because the network (topology) of spatial elements lsquocellsrsquo is constantelements lsquocellsrsquo is constant

ndashndash locally locally LagrangianLagrangian coordinatescoordinatesbullbull eg the constant mass with its motion eg the constant mass with its motion

restricted to the element cellrestricted to the element celllsquoone element passing a neighboring element lsquoone element passing a neighboring element

destroys the topologyrsquodestroys the topologyrsquo

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks

copy Peter BreedveldSummerschool Bertinoro 17-23 July 2005 (98)

SummarySummarybullbull System theoretic approach to physical system dynamicsSystem theoretic approach to physical system dynamics based onbased on

ndashndash classification of phenomena in terms of energyclassification of phenomena in terms of energyndashndash fundamental principles of thermodynamicsfundamental principles of thermodynamics

bullbull as a resultas a resultndashndash variables and relations describing physical systems may be classvariables and relations describing physical systems may be classifiedifiedndashndash models may be organized asmodels may be organized as

bullbull multiport elementsmultiport elementsbullbull interconnected in an interconnection structure corresponding to interconnected in an interconnection structure corresponding to a generalized a generalized

networknetwork

ndashndash multiport elements describe basic behaviors with respect to enermultiport elements describe basic behaviors with respect to energy and gy and entropyentropy

bullbull Explicit conceptual separation between two roles of displacementExplicit conceptual separation between two roles of displacementvariablevariable

ndashndash energy state (stored potential or elastic energy)energy state (stored potential or elastic energy)ndashndash configuration state (lsquoposition in spacersquo)configuration state (lsquoposition in spacersquo)

bullbull strongly reduces conceptual complexity even though numerical strongly reduces conceptual complexity even though numerical complexity may become temporarily highercomplexity may become temporarily higher

  • PORT-BASED MODELING OF DYNAMIC SYSTEMS fundamental concepts and bond graphs
  • Some remarks
  • General Outline
  • Introduction
  • Introduction
  • Course objectives
  • Aim
  • Fundamental issues
  • Modeling
  • Model representation
  • Physical systems modeling
  • Contents of the sequel
  • Modeling pitfalls
  • Port-based modeling
  • Physical components versus ideal elements
  • Physical component versus ideal elements
  • Physical component versus ideal elements
  • Component mounter
  • Physical components versus conceptual elements
  • lsquoParasiticrsquo elements
  • In engineering models
  • Intuitive introduction of the lsquoportrsquo concept
  • Simple model
  • Addition of relevant parasitic behavior
  • What are ports
  • Comparison with familiar model views
  • Iconic diagram symbols
  • Iconic diagram symbols
  • Iconic diagrams
  • Common block diagram models
  • Common block diagram models
  • Ports in iconic diagrams
  • Ports in iconic diagrams
  • Ports in block diagrams
  • Structure as multiport
  • Different forms
  • Different forms
  • Compact amp domain independent
  • Compact amp domain independent
  • Ports in bond graph view
  • Bond graphs
  • Analog simulation withOP-AMPS
  • Bonds
  • Ports and power bonds
  • mass-spring system
  • Dynamic conjugation
  • Power conjugation
  • Conjugate variables amp corresponding states
  • Basic dynamic behaviorsamp mnemonic codes
  • Orientation conventions
  • Convention on effort and flow positions
  • Basic one-port elements
  • Basic two- and multiport elements
  • Constitutive relations not necessarily linear
  • Other form of non-linearityModulation
  • Bilateral signal flow (computational causality)
  • Notation
  • Back to the example
  • Back to the example
  • Causal port properties
  • Causal constraints
  • Arbitrary causality
  • Causality assignment
  • Example
  • Positive orientation
  • Causality does NOT affect orientation
  • Symplectic gyrator
  • Symplectic GYrator
  • Mechanical framework of variables
  • Modulated capacitor
  • Example nonlinear 3-port C
  • Regular causal form in thermodynamics
  • Desired integral causal form
  • Form requires T0 not S0
  • Concluding remarks