Design for Assembly System Under Virtual Environment

DFA(Design for Assembly) in virtual environment is a new multidisciplinary study that integrates realtime 3D computer graphics, advanced interactive input and output devices and assemblability evaluation technology. This paper presents the architecture of an integrated DFA system in virtual environment (VirDFA). The procedures that a user manually disassembles an assembly under virtual environment are described, and all kinds of key techniques that are used to realize manual disassembly procedures and to record assembly sequences and paths in real time are investigated. In order to redesign product structures and select optimized assembly plans, an assemblability evaluation system is constructed to analyze product assembly structure and assembly sequences. The assemblability evaluation system includes a design efficiency model for assembly, an assembly complexity model, and an assembly costs model. According to the assemblability evaluation results, on the one hand, product structure can be redesigned, and on the other hand, a best assembly sequence and path can be selected wisely from a large set of feasible sequences.