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Sub assemblies
This document discusses automatic identification of sub-assemblies in an assembly. It begins with an introduction that defines assemblies and their hierarchical and complex nature. It then discusses the need for automatic sub-assembly identification to aid in assembly planning and reduce costs. The objectives are to extract information from a computer database, build liaisons, and develop an algorithm. The methodology section outlines generating a database of part mating relations and developing an algorithm to analyze the relations and identify sub-assemblies. The document concludes by noting benefits like reduced assembly costs and time through automation of sub-assembly identification.
Sub assemblies
- 1. Automatic Identification of Sub Assemblyin an Assembly Ishan Kossambe
- 2. Content • Introduction • Literaturereview • Methodology • Implementation • Conclusion
- 3. Introduction • Assembly • Need •Objectives
- 4. Assembly • Hierarchical process •Information and complex relationships • Consists of combination of sub assembly • Better final assembly
- 5. Need • Complex assembly= Number of subassembly • Assembly planning • Assembly cost • Frequent changes in design • Automatic Assembly planning
- 8. Objective • Extracting informationfrom computer database • Building of liaisons • Use of API of CAD Software • Develop an algorithm
- 9. Literature Review • Severalpapers have been published • Most of the sub assembly detection techniques makes use of mathematical models • Automation of subassembly detection • Reducing human interference
- 10. Zussman • Object graph •Kinematic Relationship Dini and Satochi • Rules for generation of sequencing Ong and Wang • Made use of connectivity and relationship Zhang • Mathematical models and computer program
- 11. Methodology 1. Generation ofdatabase 2. Development of Algorithm 3. Implementation
- 12. Generation of Database •Mating relations in the assembly are required to decide about the sub- assemblies • Code is written which extracts the mating relations • It is stored in the database
- 14. Algorithm start EXTRACT INFORMATION STORE INDATABASE . MATE MATERI AL TYPE PART EXTRACT THE MATE INFORMATION AND NUMBER OF PARTS A
- 15. A DOES PART i HASA MATE WITH PART j SAVE THE PART CONSIDER A PART AND COMPARE WITH OTHER PARTS DOES PART j HAS A MATE WITH THE i UNSAVED PART COUNT DON’T COUNT B B COUNT=1 PART i AND SAVED j PARTS IS NOT A SUB ASSEMBLY SUB ASSEMBLY END DON’T SAVE REPEATTILLi≤NUMBEROFPARTS REPEATTILLj≤NUMBEROFPARTSSAVED NO YES YES NO YES NO
- 16. Implementation • Crane HookAssembly • Extraction of mating relations using AME Algorithm • Execution of Sub-assembly detection algorithm
- 17.
- 18. Extraction Of MatingRelations
- 19. Conclusion • Reduction innumber of parts to be handled during assembly. • Assembly cost and time. • Automation. • Feasible sub-assembly detection.
- 20. Future Scope • Validatingassemblies. • Feasible sub-assembly detection.
- 21. References • J. L.Nevins and D. E. Whitney, “Concurrent design of product and processes,” McGraw-Hill, New York, 1989. • U. Rembold, C. Blume, and R. Dillmann, “Computer- integrated manufacturing technology and systems,” Mar-cel Dekker, New York, 1985. • S. S. F. Smith, “Using multiple genetic operators to re-duce premature convergence in genetic assembly plan- ning,” Computers in Industry, Vol. 54, Iss. 1, pp. 35–49, May 2004. • E. Zussman, E. Lenz and M. Shpitalni, “An approach to the automatic assembly planning problem”, Annals CIRP, 39(1), pp. 33–36, 1990. • Dini, G.; Santochi, M., “Automated sequencing and sub-assembly detection in assembly planning”, Annals of the CIRP, Vol.41, 1992. • Ong, N.S.; Wong, Y.C., “Automatic Sub-assembly detection from a product Model for disassembly sequence generation”, International journal of Advanced Manufacturing technology, Vol.15, 1999, pp. 425-431. • Y.Z. Zhang, J. Ni, Z.Q. Lin, X.M. Lai, “Automated sequencing and sub-assembly detection in automobile body assembly planning”, Journal of Materials Processing Technology, 129 (2002) 490–494. • Arun Tom Mathew; C. S. P. Rao, “A Novel Method of Using API to Generate Liaison Relationships from an Assembly”, Journal of Software Engineering & Applications, 2010, 3: 167-175
- 22.
Editor's Notes
- #5 Carries large amount of information and complex relationships
- #6 But assembly planning still poses a challenge like the description of assembly data and information specifically. There is much interest in reducing the cost of assembly activities.Assembly costs account for 10–30% of total industrial product labor costs [1], and as much as 50% of product manufacturing cost [2, 3]
- #9 Relational models represent geometric relations in the form of mating features between individual parts or subassemblies called liaisons.
- #10 E. Zussman, E. Lenz and M. Shpitalni, “An approach to the automatic assembly planning problem”, Annals CIRP, 39(1), pp. 33–36, 1990An object graph is generated which links the objects with a kinematics relationship between the objects. Subassemblies are formed from the object graph by grouping components into pairs, which have a kinematics relationship