Selective assembly of complicated mechanical product based on SPEA2

Studies of selective assembly problem were criticized for the reason that most models were confined to single dimension chain and simple structure of assemblies. To deal with this problem, a selective assembly method of complicated mechanical product under the requirement of multi-objective based on the strength Pareto evolution algorithm 2 (SPEA2) was proposed. A selective assembly model under the requirement of multi-objective was established with assembly precision and assembly yield which were taken as the criteria of evaluation. A coding method taking characteristic dimensions as genes to build chromosome was used. The primary and secondary relations of the dimension chains were described using the complexity of dimension chains. The complexity parts was used to describe the interconnection constraint reference of the characteristic dimension in the operation of evolution respectively. The strength value and density information were taken into account to build the fitness function, which was taken as the evaluation rule of the individuals. The assembly of an automobile engine cylinder was taken as an example to prove the efficiency and feasibility of the algorithm, and the optimization results were stored in the Pareto-optimal front set.