Research On Assembly Sequence Planning For Assembly Simulation

Assembly simulation is a new means for product design. Assembly simulation can make designers check product assemblability in the design phase so as to shorten product development period, reduce product costs and improve product design quality. Assembly sequence planning is important information to describe product assembly process, and it is also an important precondition to realize product assembly process simulation. In this paper, current researches on assembly sequence planning are first reviewed. Then some key questions of assembly sequence planning process are researched systematically and thoroughly as follows: (1) Based on the study of all information required by the assembly sequence planning process and the characteristics of product assembly structure, an assembly information model based on level hierarchy connection relation is put forward in this paper. This model has both advantages of level model and relation model, and also has good opening property and can expediently realize intercommunion with external information. (2) On the basis of the study of assembly structure, an assembly sequence reasoning rule-set based on the recognition of subassemblies is put forward. Using the automatic reasoning mechanism of the reasoning rule-set will significantly improve the automatization level and efficiency of assembly sequence planning. (3) Under the support of assembly information model and reasoning rule-set, AOV(Activity On Vertices) model of product assembly is built. Then a topological algorithm of directed graph is introduced to generating assembly sequence. (4) As practice and application of the above theories and algorithms, an assembly sequence automatically planning system, which is applied to box product assembly sequence planning, is developed based on the MDT platform and the system is validated by a example of gear reducer.The key point of this paper is the creation and realization of assembly information model and assembly sequence reasoning rule-set, and the application of the technology of topological sort of directed graph in the process of assembly sequence planning. Using the method presented in the paper, the question of combinatorial explosion in current researches can be overcome, so the generation of assembly sequence can be simplified.