Research On Scheduling Algorithm Of Remanufacturing Job Shop With Uncertain Process

With the rapid development of economy and the upgrading of products,the type and quantity of waste electrical and mechanical products appear explosive growth at the present stage.In order to reuse these resources and reduce pollution,the government advocates the recycling economy and green economy,and remanufacturing engineering arises at the historic moment.Job shop scheduling is one of the key technologies to achieve high efficiency,high flexibility and high reliability of the manufacturing enterprise.At present,there are a lot of research results on standard job shop scheduling model,however,due to many uncertain factors in remanufacturing process,the research results about remanufacturing job shop scheduling problem are rare,and there is a big gap between theory and practice.Process planning is the premise of scheduling,this paper focuses on the scheduling of remanufacturing job shop under process uncertain conditions,which has great theoretical value and practical significance to realize the high efficiency and high flexible production of remanufacturing enterprises.The contents of this paper are as follows:1)In view of the shortcomings of the traditional NSGAII algorithm,an improved NSGAII algorithm is proposed,including the improvement measures as follow:The process of removing duplicates and introducing new individuals to ensure the diversity of the population evolution.A cross method based on similarity is designed to ensure the cross efficiency in the prophase of the cross operation and prevent the resultless operation in the later stages.A local search operation is designed to improve the defect of local search capability of genetic algorithm to accelerate convergence.2)The job shop scheduling model was established to minimize makespan and minimize total tardiness.The improved NSGAII,SPEA,CMOEA,and MOPSO algorithm are used to solve the standard examples of 14 job shop scheduling.The comparison results show that the function value of the solution set calculated by proposed algorithm is better,and solution set contains more solution according to the comparison of function value,the Pareto frontier map and domination relationship of each solution set.3)This paper studies the characteristics of the process path in the process of remanufacturing,and proposes a method of combining integrated process planning and scheduling and re-scheduling strategy to solve the problem of uncertain process condition.A new multi-dimensional coding method and new algorithm flow which implement optimization of process and scheduling simultaneously of integrated process planning and scheduling are proposed,in order to solve the shortcoming of the traditional algorithm flow which implement optimization of process and scheduling step by step.A remanufacturing job shop scheduling model is established to minimize the makespan,the total tardiness,the total flow time,the total load of the machine,and the maximum load of the machine.Finally,this paper uses the NSGAII algorithm of the synchronization optimization process and the NSGAII algorithm and the HBMO algorithm of the traditional step-by-step optimization process to solve a numerical example.The comparison results show that the function value of the solution set calculated by proposed algorithm is better,and the proposed algorithm flow is more capable of continuous evolution according to the comparison of the mean,maximum,minimum,standard deviation,and convergence iterations of each optimization objective.