Research On Job Shop Scheduling Problem Of Aerospace Shell Based On Multi-objective Evolutionary Algorithm

Space shell is one of the key components of spacecraft,and its manufacturing requires highly precise machining and quality control.Therefore,the scheduling of aerospace shell job shop is a very critical link,which directly affects the efficiency and quality of aerospace shell manufacturing.Under the production mode of aerospace shell products presenting with multiple varieties and small batches,the production tasks of aerospace shell job shop are numerous and various,and in order to ensure the quality and efficiency of production,the production tasks of the job shop need to be reasonably allocated and optimally scheduled.This paper takes aerospace product shell manufacturing process as the research object and systematically studies the optimization method of aerospace shell production line job shop scheduling with multiple resource constraints and multiple objectives.Its main research contents are as follows:(1)Aiming at the problems of uneven task delivery distribution,tight equipment resource deployment and low equipment utilization due to many production tasks and complex production processes in the aerospace shell production line job shop,an optimal scheduling method based on improved fast nondominated sorting and decomposition-based multi-objective evolutionary algorithm is proposed.The multi-objective scheduling model of aerospace shell production line job shop with maximum completion time,maximum machine load,total resource consumption and total labor cost as the optimization objectives is established to improve the algorithm performance in terms of encoding and decoding,initialization population approach,cross-variance approach and operator design as well as individual selection strategy to improve the local search capability and convergence speed of the algorithm.(2)A multi-objective aerospace product shell production line shop scheduling problem with equipment and process constraints is proposed for the dependency relationship between processes of the same work type,and then solved using the algorithm designed in this paper and compared with the aerospace product shell shop scheduling problem without equipment and process constraints.The algorithm designed in this paper performs better with better convergence,uniformity and dispersion for 10 flexible shop scheduling example problems of different sizes.For the aerospace shell shop scheduling problem and the multiobjective aerospace product shell production line shop scheduling problem with equipment and process constraints,the algorithm designed in this paper can obtain higher quality and better convergence of Pareto optimal solutions,obtain optimal scheduling solutions,and achieve shop production task scheduling optimization.