Study On Digital Assembly Sequences Planning System

Assembly Sequences Planning (ASP), one of the important research contents of Design for Assembly (DFA), plays an important role in product design. The results of ASP, rational or irrational, have direct effect on product assemblability, assembly cost and assembly quality, which have become the focus of modern enterprise playing attention to. On the other hand, ASP is a Nondeterministic Polynomial (NP) combination optimization baffling problem on essence, how to obtain the right assembly sequence by high efficiency, lowest cost and most suitable to the relative enterprise, is the hot point of current research.This paper has first analyzed the architecture and the overall function structure of digital assembly design, and the position of ASP in digital assembly design is confirmed. Secondly, a kind of composite assembly model for assembly sequence planning is set up, the assembly model can not only describe assembly's structure, the parts' self feature information and assembly relatives, but also can describe assembly resource information; at the same time, assembly semantic is still introduce to offer local prior assembly sequence and offer semantic identification convenient to assembly model reconstruction; Thirdly, a modified Genetic Algorithm (GA), based on the above foundation, is proposed to optimize assembly sequences. And the factory application example is given to illustrate the availability of the GA. Finally, a digital assembly sequences planning system prototype which parasitizes on UG system is developed by visual C++ language, the prototype system can satisfy the preliminary needs of enterprise, and has realized preliminary function of assembly sequence planning.