Faculty of Mechanical Engineering and Naval Architecture

University of Zagreb

Croatia

ISATP’03 - THE 5th IEEE INTERNATIONAL SYMPOSIUM ON ASSEMBLY AND TASK PLANNINGSession F4B: Production System Design

Zoran Zoran KUNICAKUNICA, Ph.D., Assistant Professor, Ph.D., Assistant Professor

Professor Professor Božo Božo VRANJEŠVRANJEŠ, Ph.D., Ph.D.

IvonaIvona TTOMIOMIĆĆ, B.Sc., B.Sc.

Development of a Design Development of a Design Procedure for Automatic Assembly Procedure for Automatic Assembly

SystemSystem

I. INTRO

II. ASSEMBLY PLANNING TOOLS

III. PLANNING SOFTWARE CONTENT

IV. ASSEMBLY SYSTEM DESIGN: APPROACH & ASSUMPTIONS

V. ASSEMBLY SYSTEM DESIGN: AN EXAMPLE

VI. FURTHER WORK

CONTENT

33

I. INTRO

Despite the significant advance in integration of engineering activities and Despite the significant advance in integration of engineering activities and technical systems, technical systems, concurrent engineering approachesconcurrent engineering approaches in integration of product in integration of product design, assembly system design and assembly execution are still of pretty rare design, assembly system design and assembly execution are still of pretty rare occurrence.occurrence.

Especially, CAD/CAE Especially, CAD/CAE support for assembly system designsupport for assembly system design is still is still u underdeveloped.nderdeveloped.

The The goals of the researchgoals of the research::

• upgrading the planning methodology upgrading the planning methodology of automated of automated assembly systemassembly systems,s,

• development of the development of the CAE toolsCAE tools for planning. for planning.

In this paper, we In this paper, we have triedhave tried to identify the procedure appropriate to assembly to identify the procedure appropriate to assembly system design.system design.

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SUPPORT FOR THE PLANNINGOF AUTOMATIC ASSEMBLY SYSTEMS

General softwareDedicatedintegratedsoftware

Single programs

I-DEAS

CATIA

DFMA

Adept Digital Workcell

Adept Production Pilot

FESTO ProPneu

FESTO ProDrive

FESTO Gripper Selection

Catalogues

COSIMIR

Manufacturers

Research software(science & development)

Third-partyhttp://www.part-solutions.com

Within software

Standards (VDI 2860…)

Supporting software companies (Delmia, Tecnomatix, …)

II. ASSEMBLY PLANNING TOOLS

55

III. PLANNING SOFTWARE CONTENT

66

DFA & ASSEMBLY TECHNIQUESDFA & ASSEMBLY TECHNIQUES

ASSEMBLY SYSTEM/WORKCELL DESIGN (including: catalogues, CAD ASSEMBLY SYSTEM/WORKCELL DESIGN (including: catalogues, CAD translators & importers)translators & importers)

DEFINITION OF POSITIONSDEFINITION OF POSITIONS

PROGRAMMINGPROGRAMMING

PROGRAM OFF-LINE SIMULATION (COLLISION CHECK)PROGRAM OFF-LINE SIMULATION (COLLISION CHECK)

PROGRAM DOWNLOAD TO ROBOT/STATION CONTROLLERPROGRAM DOWNLOAD TO ROBOT/STATION CONTROLLER

PROGRAM EXECUTIONPROGRAM EXECUTION

LAYOUT OPTIMISATIONLAYOUT OPTIMISATION

PRODUCTION CYCLE OPTIMISATIONPRODUCTION CYCLE OPTIMISATION

FINANCIAL METRICSFINANCIAL METRICS

DIGITAL I/O AND WIRING DIAGRAMSDIGITAL I/O AND WIRING DIAGRAMS

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CAD CAE

PRODUCTDESIGN GENERATION

PLAN

CAM

EXECUTION PROGRAMMINGSYSTEMDESIGN

Development approaches

CAD-based Programming-based

Assembly-based

The basis for assembly system design is appropriate The basis for assembly system design is appropriate ASSEMBLY PLANASSEMBLY PLAN, which, which defines:defines: assembly sequence,assembly sequence, assembly paths,assembly paths, parts' positions (before and after assembly)parts' positions (before and after assembly),, assembly operations.assembly operations.

Assembly paths and operations imply Assembly paths and operations imply principal technical solutionsprincipal technical solutions of particular of particular assembly devices assembly devices (device type, number, kinematics and dimensions)(device type, number, kinematics and dimensions) within within assembly system.assembly system.

The equipment –The equipment – devices, for assembly system is defined in three ways: devices, for assembly system is defined in three ways: choosing among existing equipment,choosing among existing equipment, modification of the existing equipment,modification of the existing equipment, design of entirely new equipment.design of entirely new equipment.

Devices Devices areare modelled modelled interactivelyinteractively and and automaticallyautomatically during CAD session, during CAD session, and using CAD libraries and catalogues, which possess parameterised designand using CAD libraries and catalogues, which possess parameterised design base of devices. The manufacturers or third party companies base of devices. The manufacturers or third party companies (Part Solutions)(Part Solutions)make equipment available for download on internet, also.make equipment available for download on internet, also.

IV. ASSEMBLY SYSTEM DESIGN: APPROACH & ASSUMPTIONS

88

A concept of the assembly system development

PROCESS STRUCTURE & OPERATIONS

DEVOTERnon-standard components

CATALOGUEstandard

components

DEVICES

SYSTEM INTEGRATOR

ADJUSTING OF DEVICE DESIGN

99

AAssembly process/system planning

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

planning stageplanning stage an assembly system is a complementary mechanisman assembly system is a complementary mechanism

non-standard components

PRODUCT (ASSEMBLY)

ASSEMBLY SYSTEM

standard components

mechanism I – assembly paths

mechanism II – components` motions

1010

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 1111

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

1212

Origins of orientation definition

1313

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

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

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TThompson's examples of variations of living organisms

(1917)

Variants/variations of productsVariants/variations of products

Duerer's (1471-1528) 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

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.

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xz – horizontal plane

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

Hi6Hi6

Hi5Hi5Hi2Hi2

Hi4Hi4

Hi3Hi3

1717

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

1818

Treatment of identical parts in a productTreatment of identical parts in a product

Disassembled product...

Without taking into account identical parts...

Taking into account identical (yellow) parts...

Savings in space and equipment! 1919

Variants of equipmentVariants of equipment’’s s manufacturermanufacturer

ABB IRB 140 FANUC LR Mate 100i AdeptSix 300

Variants... variants... etc. ...Variants... variants... etc. ...2020

xzxz – – horizontal planehorizontal plane

A productA product – – assemblyassembly

HiHi22HiHi77

HiHi33

HiHi55

VI. ASSEMBLY SYSTEM DESIGN: AN EXAMPLE

100 mm100 mm

75 mm75 mm

7575mmmm

2121

HiHi33HiHi33HiHi55HiHi55

Disassembly simulation (sequence and paths, and positions ofDisassembly simulation (sequence and paths, and positions of parts before assembly) parts before assembly)

HiHi22HiHi22

HiHi77HiHi77

tHi7 = 397 mmtHi5 = 397 mm

tHi3 = 265 mm

tHi2 = 265 mm

Top view

2222

2323

Variant IVariant I

Double acting cylinder DSNU-25-400P-A

TThere are four identical pneumatic here are four identical pneumatic cylinders. The cylinders push parts cylinders. The cylinders push parts from their positions before from their positions before assembly, towards required final assembly, towards required final positions, to make the assembly.positions, to make the assembly.

The cylinders are pretty long, The cylinders are pretty long, implying a larger necessary space. implying a larger necessary space. The parts come in the assembly The parts come in the assembly process in ordered state -- process in ordered state -- magazines.magazines.

Assembled product Assembled product is is removed from removed from the assembly spot by a murder the assembly spot by a murder hole.hole.

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Double acting cylinder DSW-32-P-B

Variant IVariant IIIAAlmost the same as the variant I. lmost the same as the variant I. There are also four identical There are also four identical cylinders, but of another typecylinders, but of another type – with – with shorter strokes. In that way it was shorter strokes. In that way it was possible to place parts closer to the possible to place parts closer to the assembly spot (correction of position assembly spot (correction of position values obtained by assembly plan).values obtained by assembly plan).

The cylinders in both variants (I & II) The cylinders in both variants (I & II) are chosen among many available, are chosen among many available, and applicable to this specific and applicable to this specific situation.situation.

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Linear module HMP-20-400

Parallel gripper HGP-35-10

Variant Variant IIIIIITThe assembly system consists of he assembly system consists of four identical manipulators, each four identical manipulators, each containing two linear modulescontaining two linear modules, , and and havhavinging identical grippers. identical grippers.

Additionally, there is also a Additionally, there is also a pneumatic cylinder for the part pneumatic cylinder for the part Hi7.Hi7.

Three manipulators with their Three manipulators with their grippers carry the parts to the grippers carry the parts to the required final positions. The required final positions. The fourth manipulator takes the part fourth manipulator takes the part Hi7 and delivers it at the Hi7 and delivers it at the pneumatic cylinder, which pushes pneumatic cylinder, which pushes the part in its final position within the part in its final position within the product.the product.

Since the manipulators have only Since the manipulators have only two DOFs,two DOFs, included included pallets pallets should be movableshould be movable ( (two DOFstwo DOFs))..

2626

Vacuum gripper VAS-30-1/8-PUR

Variant IVariant IVV

The variant IV is similar to the variant III, except a robot equipped with a vacuum gripper is added to the part Hi7, so the cylinder from the variant III is obsolete.

2727

Variant Variant VV

The variant V is the enhancement of the variants III and IV.

The main difference -- three robots (with four DOFs each) are used in the variant V, instead of manipulators in the variants III and IV.

Consequently, movable pallets are no longer needed.

2828

Variant Variant VVII

Three identical robots from the variant V are replaced with one single robot.

The savings in equipment cost and space are obvious, but assembly cycle will be longer.

2929

Variant Variant VIVIII

Only one single robot with four DOFs, will assemble the whole product.

Since the part Hi7 requires different gripper than the rest of the parts, the assembly system should involve a possibility of gripper change.

Neglecting the gripper change subsystem, the variant VII carries further cutting of equipment and space costs. However, the assembly cycle becomes longer.

3030

Variant Equipment

Ranking criterion

Productivity, 60 %

Price, 25 %

Flexibility, 10 %

Space, 5 %

I4 pneumatic cylinders DSNU-25-400P-A, magazines, murder hole

4 5 3 4 4,15

II4 pneumatic cylinders DSW-32-P-B, magazines, murder hole

5 5 3 5 4,8

III4 manipulators+grippers, pneumatic cylinder, movable pallets, murder hole

3 3 4 1 3

IV

3 manipulators+grippers, robot+vacuum gripper, 3 movable pallets, fixed pallet, fixed pallet for assembled products

3 2 5 3 2,95

V 4 robots+grippers, 5 fixed pallets 3 1 5 2 2,65

VI 2 robots+grippers, 5 fixed pallets 2 3 5 4 2,65

VIIsingle robot, 2 grippers, five fixed pallets

1 4 5 5 2,35

Comparison of the assembly system variants

VII. FURTHER WORK

S. FreudS. FreudS. FreudS. Freud & Eric Berne`s transactional analysis& Eric Berne`s transactional analysis

Detailed variant design of devices, including:

• analysis and optimization of (dis)assembling paths (directions and lengths),

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

Implementation of assessment criteria.

Automation of the design procedure.

Experiments with concurrent generation of assembly plans and systems.

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

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

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