Design Methodology in the Development of Mechatronic Products 2006/Design Methodology/De… ·...

Design Methodology in the Development of Mechatronic Products- Part 1

Robert BjärnemoDivision of Machine Design at the Department of Design Sciences

Agenda

On the Concept of On the Concept of MechatronicsMechatronics

Characteristics of an Intelligent Characteristics of an Intelligent MechatronicMechatronic SystemSystem

Engineering Design and Engineering Design and MechatronicsMechatronics

On the Concept of Intelligent SystemsOn the Concept of Intelligent SystemsOn Product and Systems ArchitectureWhat is Product Architecture?Establishing the Product ArchitectureHandling Interface Problems

What is What is MechatronicsMechatronics? ? BSDB p 12BSDB p 12

According to According to ““MechatronicsMechatronics and the design of intelligent and the design of intelligent machines and systems”machines and systems” by Bradley, Seward, Dawson and by Bradley, Seward, Dawson and Burge (BSDB) Burge (BSDB) MECHATRONICSMECHATRONICS is described as:is described as:

““MechatronicsMechatronics provides both a provides both a title and a focustitle and a focus for for the the design and developmentdesign and development of a wide range of of a wide range of engineering systems, both engineering systems, both productsproducts and and processesprocesses, in which the , in which the technologies of technologies of electronics, software engineering and information electronics, software engineering and information systemssystems are integrated with mechanical are integrated with mechanical engineering.engineering.””

The Constitutive Elements of The Constitutive Elements of MechatronicsMechatronics BSDB p 11BSDB p 11

MECHANICALMECHANICALENGINEERINGENGINEERING

MechanizationMechanizationElectro Electro –– MechanicalMechanical

SystemsSystems

ElectricalElectricalTechnologyTechnology

InformationInformationTechnology &Technology &SoftwareSoftware

ElectronicsElectronics

MECHATRONICSMECHATRONICS

The General Structure and Concept of The General Structure and Concept of MechatronicsMechatronicsand and MechatronicsMechatronics Systems Systems BSDB p 12BSDB p 12

The Major Characteristics of an Intelligent The Major Characteristics of an Intelligent MechatronicMechatronic System System BSDB p 14BSDB p 14

generally complex systems exhibiting high levels of generally complex systems exhibiting high levels of integration;integration;

increased functionality with respect to conventional increased functionality with respect to conventional systems;systems;

transfer of function from the mechanical to the transfer of function from the mechanical to the electronics and software domains;electronics and software domains;

system assumes responsibility for process allowing system assumes responsibility for process allowing operator to concentrate on procedures;operator to concentrate on procedures;

distributed processing with devolved intelligence;distributed processing with devolved intelligence;

multimulti--sensor environment; sensor environment;

system operation generally transparent to user;system operation generally transparent to user;

multimulti--program environment with user selection.program environment with user selection.

An Example of a An Example of a MechatronicMechatronic SystemSystem–– A A CameraCamera BSDB p 14BSDB p 14

Determining the required Determining the required combination of aperture and combination of aperture and shutter speed and of shutter speed and of maintaining focus becomes maintaining focus becomes the responsibility of the the responsibility of the camera. camera. The The useruser is therefore is therefore freed to freed to concentrate on achieving the concentrate on achieving the desired composition! desired composition!

Automatic, auto focus reflex camera with interchangeable Automatic, auto focus reflex camera with interchangeable lenses lenses -- in which each of the major 'hard' elements of the in which each of the major 'hard' elements of the system; body, lens and flashsystem; body, lens and flash--gun, constitutes a gun, constitutes a

mechatronicmechatronic systemsystem in its own right.in its own right.

MechatronicMechatronic Relationships Relationships BSDB p 20BSDB p 20

Engineering Design and Engineering Design and MechatronicsMechatronics ––Positioning Engineering Design Positioning Engineering Design BSDB p 23BSDB p 23

Engineering Design and Engineering Design and MechatronicsMechatronics ––Development and Design CostsDevelopment and Design Costs BSDB p 22BSDB p 22

Percentage of total costPercentage of total cost

Development phaseDevelopment phase IncurredIncurred CommittedCommittedConceptual DesignConceptual Design 3 3 –– 55 40 40 -- 6060Embodiment DesignEmbodiment Design 5 5 –– 88 60 60 -- 8080

TestingTesting 8 8 –– 1010 80 80 -- 9090

Process PlanningProcess Planning 10 10 –– 1515 90 90 -- 9595ProductionProduction 15 15 –– 100100 95 95 –– 100100

The Cost of Design ChangeThe Cost of Design Change Relative CostRelative CostDuring DesignDuring Design 11During TestingDuring Testing 1010During Process PlanningDuring Process Planning 100100During Pilot ProductionDuring Pilot Production 10001000During Final ProductionDuring Final Production 1000010000

On the Concept of Intelligent Systems On the Concept of Intelligent Systems –– What is Intelligence? What is Intelligence? BSDB p 40BSDB p 40

intelligence, n. 1 a the intellect; the understanding. b (of a person or animal) quickness of understanding; wisdom. 2 a the collection of information, esp. of military or political value. b people employed in this. c information so collected. d archaic information in general; news. 3 an intelligent or rational being. intelligential adj. [Middle English via Old French from Latin intelligentia (as INTELLIGENT)]. Concise Oxford Dictionary, 9th edn, 1995

On the Concept of Intelligent Systems On the Concept of Intelligent Systems –– An Typical Intelligence Test Question An Typical Intelligence Test Question BSDB p 41BSDB p 41

4343

1616

7070

2525

1515

Which is “ the odd one out”? Which is “ the odd one out”?

On the Concept of Intelligent Systems On the Concept of Intelligent Systems –– Aspects of Human and Machine Intelligence Aspects of Human and Machine Intelligence BSDB p 42BSDB p 42

On the Concept of Intelligent Systems On the Concept of Intelligent Systems ––The Turing Test The Turing Test BSDB p 43BSDB p 43

A human interrogator has two dumb terminals, one of which is connected to a computer and the other to a human operator as in the figure. The interrogator can send and receive messages via these terminals. If after any length of time the interrogator cannot tell which of their two terminals is connected to the computer and which to the human operator, then the computer may be said to be intelligent.

On the Concept of Intelligent Systems On the Concept of Intelligent Systems ––Types of Machine Intelligence Types of Machine Intelligence BSDB p 43BSDB p 43

Description Example Characteristics

Single Function Drill Capable of only one operation

Automatic Pick and place mechanism Carries out a single fixed sequence

Programmable CNC machine tool Carries out a sequence of operations under programme control

Adaptive Fly-by-wire aircraft Autonomously adapts to changing conditions using sensory feedback.

Goal Seeking Self guided vehicle Adapts to changes in environment in relation to a defined goal

Advanced Data Capable of strategic decision makingAutonomous and planning

On Product and Systems ArchitectureOn Product and Systems Architecture BSDB p 52BSDB p 52

Within electronic engineering and software engineering, as well as for products in general, the term architecture, or more specifically product architecture, is used to describe the organization and structure of a system or a product and the ways in which the various elements of the product/system interact. The choice of product/system architecture is therefore likely to be a critical factor in determining the way in which an intelligent machine or a product operates.


Von Neumann architectureNamed after the mathematician John von Neumann, this architecture describes the configuration of most common computer systems. Also referred to as a random access sequential machine, a von Neumann architecture assumes the existence of a central processor and read-write random access memory as in the figure. In operation, the processor sequentially executes instructions stored in memory using data stored elsewhere in memory.


Parallel architectureParallel architectures are based around a number of processors sharing access to common memory as in the figure. Execution of instructions is allocated to individual processors in turn according to loading, enabling significantly shorter processing times to be achieved.

On Product and Systems Architecture On Product and Systems Architecture BSDB pp 52 BSDB pp 52 -- 53 53

Distributed and embedded systems architecturesIn a distributed architecture, processing power is devolved to individual elements or components within the system, each of which essentially runs its own independent program based on local memory.

Thus in the camera system, each of the elements; body, lens, flash gun and data back; contains all the processing capability required to enable it to operate as part of the overall system together with an appropriate interface to enable communication with the other elements of the system.


Hierarchical architectureA hierarchical architecture is organized as a tree structure such as that shown in the figure, in which each member, with the exception of the topmost member and bottommost members of each branch, are both the parents to the members of the hierarchy in the layer below them and children of a member of the hierarchy in the layer above them. Thus at the top level of the hierarchy sits the complete system while the lowest level of each branch describes one of the individual elements or components that make up the complete system. Information flows up and down the layers in the hierarchy in a strictly ordered manner from parent to children and vice versa.

SystemSystem


Network architecturesNetworks may take a variety of forms such as those shown in the left figure. Unlike a hierarchical configuration, all members of a network are essentially equal, though there may be some bias in order to assign priorities to certain nodes. Each node of the network can itself be based around a microprocessor or micro controller which provides local processing power and hence forms the basis of the distributed and embedded system that is at the heart of many mechatronic systems. Thus, the camera, below, can be redrawn as a bus architecture with the processor in the main body acting as system controller.

What is Product Architecture?

In a product the In a product the physical elementsphysical elements are typically organized into are typically organized into several major several major physical building blocksphysical building blocks or or chunks chunks or simply or simply subsystems.subsystems.

A A product architectureproduct architecture is the scheme by which the is the scheme by which the functional functional elements of the product are arranged into physical chunks elements of the product are arranged into physical chunks and by which the chunks interact.and by which the chunks interact.

The The product architectureproduct architecture belongs to either of the two main belongs to either of the two main groups: groups:

Integral architectureIntegral architectureModular architectureModular architecture

Integral Product Architecture

An An integral product architectureintegral product architecture exhibit one or more of the exhibit one or more of the following properties:following properties:

Functional elements of the product are implemented using more Functional elements of the product are implemented using more than one chunk.than one chunk.

A single chunk implements many functional elements.A single chunk implements many functional elements.

The interactions between chunks are defined and may be The interactions between chunks are defined and may be incidental to the primary functions of the product.incidental to the primary functions of the product.

Example – Integral Product Architecture

The BMW R1100RS exhibits The BMW R1100RS exhibits function sharing and an function sharing and an integral architectureintegral architecture with the with the design of its transmission design of its transmission chunkchunk..

Modular Product Architecture

A A modular modular product architectureproduct architecture has the following properties:has the following properties:

Chunks implement one or a few functional elements in their Chunks implement one or a few functional elements in their entirety. entirety.

The interactions between chunks are well defined and are The interactions between chunks are well defined and are generally fundamental to the primary functions of the product.generally fundamental to the primary functions of the product.

In the In the completelycompletely modular product modular product each functional element of each functional element of the product is implementedthe product is implemented byby exactlyexactly one one physical chunk and physical chunk and in which there are a few wellin which there are a few well--defined interactions between the defined interactions between the chunks.chunks.

Types of Modularity

SlotSlot--Modular ArchitectureModular ArchitectureEach of the interfaces between chunks in a slot-modular architecture is of a different type from the others, so that the various chunks in the product cannot be interchanged.

Sectional-Modular Architecture

In a sectional-modular architecture, all interfaces are of the same type, but there is no single element to which all of the other chunks attach.

BusBus--Modular ArchitectureModular Architecture

In a bus-modular architecture, there is a common bus to which the other chunks connect via the same type of interface.

Platform Product

A A platform product is built around a preexisting technological is built around a preexisting technological subsystem (a technological platform).subsystem (a technological platform).

Examples: Sony Walkman and the Hasselblad camera.Examples: Sony Walkman and the Hasselblad camera.

Product built on technology platforms are much simpler to Product built on technology platforms are much simpler to develop than if the technology was developed from scratch.develop than if the technology was developed from scratch.

Example – Platform Product

Powertrain: engines, transmissions, shifts Chassis front & rear: suspensions, brakes Engine cradle and rear suspension frameSteering system: steering gear Exhaust system Fuel storage and handling systemHeat,Ventilation & AC systemCooling system, intercoolers, condensers I/P structure, cross bar & knee protection Steering column, except steering wheel Underbody, front & rear structuresFront & rear seat structuresMoveable roof cassettesCharging & energy storage

Official GM Platform Definition

Establishing the Product Architecture

Step 1: Create a Schematic of the ProductStep 1: Create a Schematic of the Product

A A schematic is a diagram is a diagram representing the development representing the development team’s understanding of the team’s understanding of the constituent elements of the constituent elements of the product.product.

Here a schematic of the DeskJet Here a schematic of the DeskJet printer printer –– by HP. Note the by HP. Note the presence of both presence of both functional functional elementselements (e.g. “Store Output”) (e.g. “Store Output”) and and physical elementsphysical elements (e.g. (e.g. Print Cartridge”). For clarity not Print Cartridge”). For clarity not all connections among the all connections among the elements are shown!elements are shown!


Step 2: Cluster the Elements of the SchematicStep 2: Cluster the Elements of the Schematic

The challenge here is to The challenge here is to assign each of the elements assign each of the elements of the schematic to a chunk.of the schematic to a chunk.

In order to facilitate the In order to facilitate the clustering following factors are clustering following factors are considered:considered:

Geometric integration and Geometric integration and precisionprecision

Function sharingFunction sharing

Capabilities of vendorsCapabilities of vendors

Similarity of design or Similarity of design or production technologyproduction technology

Location of chanceLocation of chance

Accommodating varietyAccommodating variety

Enabling standardizationEnabling standardization

Portability of interfacesPortability of interfaces


Step 3: Create a Rough Geometric LayoutStep 3: Create a Rough Geometric Layout

Creating a geometric layout Creating a geometric layout forces the the team to consider forces the the team to consider whether the geometric whether the geometric interfaces among the chunks interfaces among the chunks are feasible and to work out the are feasible and to work out the basic dimensional relationships basic dimensional relationships among the chunks.among the chunks.


Step 4: Identify the Fundamental and Incidental InteractionsStep 4: Identify the Fundamental and Incidental Interactions

It is most likely that a different It is most likely that a different person or group will be person or group will be assigned to design each chunk.assigned to design each chunk.

Because the chunks interacts Because the chunks interacts with one another in both with one another in both planned planned and and unintended unintended waysways, these groups will have to , these groups will have to coordinate their activities and coordinate their activities and exchange information between exchange information between the chunks. the chunks.

An An interaction graph is a is a convenient way to represent convenient way to represent the incidental interactions.the incidental interactions.

Handling Interface Problems

The following steps are to be carried out:The following steps are to be carried out:

1.1. Identification of the overall system (incl. its inIdentification of the overall system (incl. its in-- and output vectors).and output vectors).

2.2. Identification of subsystemsIdentification of subsystems

3.3. Identification of type of interface Identification of type of interface

4.4. Development of physical interfaceDevelopment of physical interface--elementelement

The method presented here is based on the concept of The method presented here is based on the concept of featurefeature

based transformationsbased transformations between the constituent subsystems.between the constituent subsystems.

Step 1: Identify the Overall System

Type of systemType of system IdentifierIdentifier Version numberVersion number

INPUTINPUT OUTPUTOUTPUT

Transfer functionTransfer function

Output statusOutput statusInput statusInput status

Step 2: Identification of Subsystems

An An interface problemsinterface problems is at hand when the output form is at hand when the output form subsystem 1 doesn’t match the input to subsystem 2!subsystem 1 doesn’t match the input to subsystem 2!

Step 3, 4: Identifying Type of Interface and Identifying Type of Interface and Develop Physical InterfaceDevelop Physical Interface--elementelement

Example - Flange

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