Faculty of Mechanical Engineering and Naval Architecture

Development of a Development of a SSystem for ystem for CConcurrent oncurrent EEngineering ngineering AAssembly ssembly PPlan lan

GGenerationeneration

Zoran KUNICA, Ph.D., Assistant Professor

Professor Božo VRANJEŠ, Ph.D.

Miljenko HRMAN, B.Sc., Postgraduate student -- trainee

University of Zagreb

Croatia

Section:Section:ISMS 2001:ISMS 2001: Processes and SystemsProcesses and Systems

Third International ICSC-NAISOWORLD MANUFACTURING CONGRESS

April 2-5, 2002, Rochester, New York, U.S.A.

INTROINTRO

The most of the products have more than one part... so they must be assembled.

The goal of the research: development of CAE component that would allow more efficient assembly planning in the effort to integrate:

• the product design,• assembly system design.

The motivation of the research:• upgrading the assembly system planning methodology,• development of the computer support for planning.

Recent explorations:• the necessity of assembly and assembly-related knowledge

synthesis, compilation and integration (concurrent engineering);• automatic vs. interactive process/system generation;• variants and combinatorial complexity;• shift of interest to still uncovered aspects of the human process

planning, which is intuitive to a great extent.

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33

The Production PILOT, still developing suite of products, consists of assembly process design, simulation, and analysis tools, built into 3-D graphical environment, and seems to be good example of future trend of development and practice (SILMA, 2001).

ASSUMPTIONSASSUMPTIONS

44 Assembly process/system planning

a product -- an assembly, exists as CAD model assembly and disassembly are inverse issues a product is a virtual mechanism, that should be recognized during

planning stage an assembly system is a complementary mechanism

non-standard components

PRODUCT (ASSEMBLY)

ASSEMBLY SYSTEM

standard components

mechanism I – assembly paths

mechanism II – components` motions

PLAN GENERATION SYSTEM & ELEMENTS

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SOME PLAN ELEMENTSSOME PLAN ELEMENTS

For an automatically generated initial disassembly sequence, instead of the criterion distance of the part centre of gravity from the product centre of gravity, the combination of three criteria is used:

• distance of the part centre of gravity from the product centre of gravity,

• the value of y component of the part centre of gravity,

• part volume (mass).

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One criterion...

The improvedalghorithm – three criteria...

The example of advantages of using combination of criteria for initial disassembly sequence...

the main part

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EXAMPLES OF PLAN GENERATIONEXAMPLES OF PLAN GENERATION

Microsoft PowerPoint Presentation

99

DEVELOPMENT OF THE ASSEMBLYDEVELOPMENT OF THE ASSEMBLYPLANNING SYSTEMPLANNING SYSTEM

An assembly planning environment should combine tools distributed in two levels:

1. pretools within activities prior to assembly planning,

2. assembly planning CAE component (posttool) that follows product design process.

Assembly planning and activities of product design 1010

Discrepancy in orientation: natural orientation of the part (A), technological orientation (B), orientation required in a product (C)

1111

Origins of orientation definition

1212

Example of definition of plan generation parameters

ASSEMBLY PLAN GENERATIONOPTIONS

ASSEMBLY PLAN GENERATIONOPTIONS

Automatic generation Onof assembly sequence Off Off

Automatic generation Onof assembly sequence Off Off

Connectivity Oncheck Off OffConnectivity Oncheck Off Off

.

.

....

Automatic generation Onof assembly system layout OffOff

Automatic generation Onof assembly system layout OffOff

Product class Product class

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Planning procedure should be analysed as a combination of automatically and interactively generated elements.

A concept of the intelligent assembly system development

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INTELLIGENT ASSEMBLY SYSTEM DEVELOPER

PROCESS STRUCTURE

DEVICES

CATALOGUEstandard

componentsOPERATIONS

DEVOTERnon-standard components

SYSTEM INTEGRATOR

ADJUSTING OF DEVICE DESIGN

Thompson's examples of variations of living organisms

(1917)

Variants/variations of productsVariants/variations of products

Duerer's examples of variations of living organisms

 Two solutions of the same mechanism (Blanding,

1999)

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1 Product

2 3 4 5 6

[1, 0, 0, 0, 0

[1, 1, 1, 1, 1

[1, 2, 2, 2, 2

[1, 0, 0, 1, 2

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Some of the structures for a product with six parts (Beneath the graphical presentation of each structure the structure’s numerical code is given.)

Variations of assembly processVariations of assembly process

The assembly process can be represented and modelled using generic structures – generic plans.

The structures show the space and time possibility of the assembly process realisation.

xz – horizontal plane

Variants of product`sVariants of product`s initial oinitial orientarientationtion

Hi6Hi6

Hi5Hi5Hi2Hi2

Hi4Hi4

Hi3Hi3

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Variants of Variants of pparts’arts’ layoutlayout

Rotary-table(D = 1234,212 mm)

Line assembly(L = 8639,487 mm)

.Hi5

Hi4

Hi2

Hi3

Hi6

z distance Hi5-Hi6:

5924,22 mm

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Variants of equipmentVariants of equipment’’s s manufacturermanufacturer

ABB IRB 140

2020

FANUC LR Mate 100i AdeptSix 300

Variants... variants... etc. ...Variants... variants... etc. ...

FURTHER WORKFURTHER WORK

Experiments with concurrent generation of assembly plans.

Modelling of CE planning situations and roles (procedures, protocols and data sharing).

Analysis and optimisation of (dis)assembling paths (directions, lengths).

Simulation of assembly operations and assembly techniques (forces, deformable joints - snap fitting, ...).

Assembly device design and development of a CAD catalogue of devices.

Human planner's mental activities and behavior -- conscience and non-conscience (intuitive) aspects of the planning.

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S. FreudS. Freud

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