SCSC 2003Montreal, Canada

22 July, 2003

Computer Aided Multi-paradigm Modelling

of Hybrid Systems with AToM3

Juan de Lara and Manuel Alfonseca

E.T.S. de InformaticaUniversidad Autonoma de Madrid, Madrid, Spain

Hans Vangheluwe

Modelling, Simulation and Design Lab (MSDL)School of Computer Science, McGill University, Montreal, Canada

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Presentation Overview� Multi-paradigm Modelling and Simulation

� An example Hybrid model

� Meta-modelling

� AToM3: A Tool for Multi-formalism Meta-Modelling

� The future . . .

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Multi-paradigm modelling and simulation

1. Different levels of abstraction

2. Mixing different formalisms (coupling, transformation)

3. Modelling classes of models (formalisms) by meta-modelling

4. Modelling transformations explicitly

(in the Graph Grammar formalism)

TOMACS 12(4) 2002: Special Issue on CAMPaM.

Mosterman and Vangheluwe.

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A Hybrid Example: T � l controlled liquid

is_full

is_emptyheat

off

cool

is_coldis_hot

fill emptyclosed

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A Simulation Applet

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OOCSMP to Java applets with C-OOL

Simulation 79(1) 2003: Visual Interactive Simulation for Distance

Eductation. de Lara and Alfonseca.

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The Controller (Statechart)

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Meta-modelling

meta-model a model in formalism MF

meta-modelprocessor model

userinput

a model of a class of models (the formalism F)semantics within formalism MFdescribes: structure and constraints

a model in formalism F

-create-delete-verify (local, global)

MF

F

(ER)

(FSA)

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Statecharts Meta-model

Name type=String init.val

Blob

Name type=String init.val

Orthogonal

Actions type=String init.

Initial

Hyperedge

composed_of

has_inside

has_Initialiconnection

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Statecharts Meta-model in AToM3

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Edit Entity

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Edit Entity Appearance

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The Controller (Statechart)

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The Continuous Plant Model (ALG + ODE)

Inputs (discontinuous � hybrid model):

� Emptying, filling flow rate φ

� Rate of adding/removing heat W

Parameters:

� Cross-section surface of vessel A

� Specific heat of liquid c

� Density of liquid ρ

State variables:

� Temperature T

� Level of liquid l

Outputs (sensors):

� is low � is high � is cold � is hot

������������� �����������

�

dTdt

1l W

cρA

� φT �

dldt

φ

is low l � llow �

is high l � lhigh �

is cold T � Tcold �

is hot T � Thot �

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A Causal Block Diagram Model

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CBD Meta-model (ER)

Type type=Enum init.valueValue type=Float init.valName type=String init.valInitialCondition type=PorVariable type=Port init.v

Block

Name type=String init.valValue type=Float init.val

Constant

Type type=Enum init.valueLocation type=Enum init.v

Output

Type type=Enum init.value

Control_Variable

Connected_to_Block

Connected_Ct

Connected_Out

Connected_Ctrl

Connected_out_ctrl

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x� � � � Kx � x � 0 � � 0 � x� � 0 � � 1

x0

0.0

y0

1.0

ICx

ICy

− I OUT

K

1.0

0.0

PLOT

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Generated LATEX

\[

\left\{

\begin{array}{ll}

\dot{x} = y, & x(t_0) = x0\\

\dot{y} = -(x) \cdot K, & y(t_0) = y0\\

\\

x0 = 0.0\\

K = 1.0\\

y0 = 1.0\\

\end{array}

\right.

\]

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Rendered

������������� �����������

�

x y � x t0 � x0

y � x ��� K � y t0 � y0

x0 0� 0

K 1� 0

y0 1� 0

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Generated Matlab/Simulink

function xdot = harmonic(t, x)

xdot = zeros(2, 1);

xdot(1) = x(2);

xdot(2) = -(x(1)) *1.0;

x0 = [0.0; 1.0];

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The OOCSMP top-model

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OOCSMP meta-model (ER)

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The Complete Model

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Meta-meta-. . .

meta-metamodel

meta-modelprocessor

meta-modeluserinput

a model of a class of models (the formalism MF)semantics within formalism MMFdescribes: structure and constraints

a model in formalism MF

-create-delete-verify (local, global)

meta-modelprocessor model

userinput

a model of a class of models (the formalism F)semantics within formalism MFdescribes: structure and constraints

a model in formalism F

-create-delete-verify (local, global)

MMF

MF

F

(ER)

(ER)

(FSA)

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ER Meta-model (ER)

name type=String init.valattributes type=List init

ERentity

ERrelationship

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Model Transformation Specification

meta-model a model in formalism ER

meta-modelprocessor

model

userinput

a model of a class of models (the formalism NFA)semantics within formalism ER

a model in formalism NFA

-create-delete-verify (local, global)

MF

F

(ER)

(NFA)

meta-model a model in formalism MF

meta-modelprocessor

model

userinput

a model of a class of models (the formalism F)semantics within formalism MFdescribes: structure and constraints

a model in formalism FSA

-create-delete-verify (local, global)

MF

F

(ER)

(FSA)(multi-formalism)

model transformer=

meta-modelprocessor

transformationmeta-model

MF (GGR)

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The Full Picture

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Related Work� The OMG’s Model Driven Architecture (MDA)

� Graph Grammars: PROGRES, AGG, . . .

� Ptolemy (Berkely, Ed Lee): co-simulation

� Vanderbilt (ISIS): Multigraph Architecture, GME

� Honeywell: DOME

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The Future . . .� Domain-specific modelling and simulation environments

� Experiment with variations (flavours) of formalisms (syntax and

semantics)

� Formalism Transformation (FTG)

� Graph Grammars models for all Transformations

� Simulator Meta-specification (reference implementation)

� Model exchange (DTD from meta-model, XML from model)

� Concrete vehicle: ATOM3 http://atom3.cs.mcgill.ca

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Acknowledgements� The Modelling, Simulation and Design Lab (MSDL)

http://msdl.cs.mcgill.ca

� Jean-Sebastien Bolduc (CBD transformations)

� NSERC http://www.nserc.ca

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