Faculty of Mechanical Engineering and Naval Architecture

1. Third International ICSC-NAISO WORLD MANUFACTURING CONGRESS April 2-5, 2002, Rochester, New York, U.S.A. Section: ISMS 2001:Processes and Systems Development of a System for Concurrent Engineering Assembly Plan Generation Zoran KUNICA, Ph.D., Assistant Professor Professor Božo VRANJEŠ, Ph.D. Miljenko HRMAN, B.Sc., Postgraduate student -- trainee Faculty of Mechanical Engineering and Naval Architecture University of Zagreb Croatia

2. INTRO The most of the products have more than one part...so they must be assembled. The goal of the research: development ofCAEcomponent 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. 2

3. 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). 3

4. PRODUCT (ASSEMBLY) mechanism I – assembly paths mechanism II – components` motions ASSEMBLY SYSTEM standard components non-standard components ASSUMPTIONS • 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 Assembly process/system planning 4

5. PLAN GENERATION SYSTEM & ELEMENTS 5

6. SOME PLAN ELEMENTS For an automatically generated initial disassembly sequence, instead ofthe criterion distance of the part centre of gravity from theproduct centre of gravity, the combination of three criteriais 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). 6

7. One criterion... The improved alghorithm – three criteria... The example of advantages of using combination of criteria for initial disassembly sequence... the main part 7

8. EXAMPLES OF PLAN GENERATION 9

9. DEVELOPMENT OF THE ASSEMBLY PLANNING 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 10

10. Discrepancy in orientation: natural orientation of the part (A), technological orientation (B), orientation required in a product (C) 11

11. Origins of orientation definition 12

12. ASSEMBLY PLAN GENERATION OPTIONS Product class  Connectivity On check Off Automatic generation On of assembly sequence Off Automatic generation On of assembly system layout Off . . . Planning procedure should be analysed as a combination of automatically and interactively generated elements. Example of definition of plan generation parameters 13

13. INTELLIGENT ASSEMBLY SYSTEM DEVELOPER CATALOGUE standard components PROCESS STRUCTURE DEVICES OPERATIONS ADJUSTING OF DEVICE DESIGN DEVOTER non-standard components SYSTEM INTEGRATOR A concept of the intelligent assembly system development 14

14. Variants/variations of products Thompson's examples of variations of living organisms (1917) Duerer's examples of variations of living organisms  Two solutions of the same mechanism(Blanding, 1999) 15

15. Variations 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. Some of the structures for a product with six parts (Beneath the graphical presentation of each structure the structure’s numerical code is given.) 16

16. Hi6 Hi4 Hi3 Hi5 Hi2 • Variants of product`sinitial orientation xz – horizontal plane 17

17. Line assembly (L = 8639,487 mm) Variants of parts’layout . Hi5 Rotary-table (D = 1234,212 mm) Hi4 z distance Hi5-Hi6: 5924,22 mm Hi2 Hi3 18 Hi6

18. Variants of equipment’s manufacturer FANUC LR Mate 100i AdeptSix 300 ABB IRB 140 • Variants... variants... etc. ... 20

19. S. Freud FURTHER 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, deformablejoints - 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. & Eric Berne`s transaction analysis 21