Research On Methods Of Multi-station Assembly Sequence Planning For Complex Product

Assembly sequence planning is the core of complex product assembly planning,and the result determines the subsequent assembly process and the complexity of the assembly process,which ultimately affects the product assembly quality and assembly costs.Multi-station assembly line as a widely used production method for complex product assembly,can effectively reduce the product manufacturing cycle,improve the quality of assembly,and maximize the utilization of resources.In order to solve the shortcomings of the traditional assembly sequence planning,this paper studies the multi-station assembly sequence planning combined with the assembly line balance,and mainly breaks through the two key technologies at determination of evaluation method and assembly sequence optimization in multi-station assembly sequence planning,which simultaneously achieves the optimization of assembly sequence in the requirements of assembly process and assembly station.The main contents of this paper are as follows:(1)Based on the analysis of multi-station assembly sequence,the overall framework of multi-station assembly sequence planning of complex products is proposed.The information requirement of multi-station assembly model is analyzed,the expression method of assembly information model is introduced,and a multi-level assembly information model for multi-station assembly sequence planning is established.(2)A multi-station assembly sequence evaluation system is established with the consideration of part-level factors,product-level and work-level factors.The matrix storage expression method of assembly information model is proposed and the corresponding algorithms for matrix generation are given.Combined with the extracted assembly information,the mathematical models of each evaluation index are established.The optimal orderly reference set method is used to realize the comprehensive evaluation of part level indexes.A two-level fuzzy evaluation model is constructed.The fuzzy comprehensive evaluation of assembly sequence is realized by the combination of AHP and fuzzy comprehensive evaluation.(3)A discrete particle swarm optimization algorithm for multi-station assembly sequence planning is established.In order to solve the problem of premature convergence in the algorithm,an adaptive inertia weight of dynamic decreasing method is proposed.At the same time,the chaotic mutation is introduced into the particle swarm optimization based on chaos characteristics of randomness and ergodicity.An improved particle swarm optimization algorithm is proposed,and the sensitivity of the algorithm parameters is analyzed.Through example application and algorithm comparison analysis,the effectiveness and superiority of the improved particle swarm algorithm to solve the multi-station sequence programming problem are proved.(4)A multi-station assembly sequence planning prototype system has been developed on the DELMIA V6 software platform.The application process of each function module has been illustrated by an instance of a aircraft landing gear.The theory and method of multi-station assembly sequence planning are verified.