Abstract: Concurrent assembly of complex product is restricted by various factors, which makes concurrent assembly sequence planning more difficult. The concurrent assembly sequence planning method based on fuzzy rough sets is proposed. Concurrent degree is defined as the overall constraint parameter of concurrent assembly, and the part assembly indicator table is given to depict the assembly characteristic parameter, structure characteristic parameter and restriction characteristic parameter of each part in the assembly. According to these parameters, parts to be installed are taken as knowledge universe, and appropriate membership degree function as assessment index is brought forward to define the indiscernibility relation. In the knowledge base made of knowledge universe and indiscernibility relation, the fuzzy rough sets model is adopted to generate the concurrent assembly sequence. The effectiveness of the method is verified by actual assemblies of machine vice and plasma enhanced chemical vapor deposition.

Key words: Assembly constraint, Concurrent assembly sequence, Concurrent degree, Fitness membership degree, Fuzzy rough sets