Research On Process Planning And Flexible Job Shop Scheduling For Part Family

At present,China's economy is in the period of transformation and upgrading to high-quality development,and in the context of the global transformation to intelligent manufacturing,many small and medium-sized enterprises in the manufacturing industry are facing great changes in the market situation,and the market demand of multiple varieties and small and medium-sized batches has become the norm.In this situation,how to effectively organize production to meet market demand,reduce production costs and improve production efficiency has become an urgent problem for many small and medium-sized enterprises.In this paper,the machining workshop of an electric motor company is taken as the research object.From the perspective of process centralized optimization,the group technology is proposed to classify the multi variety parts into groups.Based on the parts classified into groups,the compound parts method is used to design the process specification of the corresponding part family and optimize the process route of the part family.Then,taking the part family process route as the process constraint,the model of multi-objective flexible job shop scheduling problem with completion time,total machine load and processing cost is established and its solution algorithm is studied,which provides a reference for reducing the production preparation time,shortening the time of multi product in process and improving the production efficiency.The main contents of this paper are as follows:First of all,based on the planning and design requirements and production drawings of the NC machining production line of the motor shell parts,through the study of parts classification,the parts are classified into groups by using group technology,and different types of parts families are obtained.Then,the composite parts method is used to optimize the machining process of each part family,in which two process planning schemes are designed for each part family Through the comprehensive comparison of the subject matter,the optimal scheme is selected,and then the optimal process route of the part family is obtained,which provides the process constraints for the workshop scheduling.Secondly,in order to make the production scheduling model more in line with the actual production situation of the machining workshop,this paper constructs a multi-objective flexible job shop scheduling model with the completion time,total machine load and processing cost as the optimization objectives.Thirdly,aiming at the selection and design of the algorithm for solving the model,this paper describes the excellent ability of NSGA-? with elite strategy to solve the multi-objective problem.Based on the operation mechanism of NSGA-? algorithm,this paper designs the coding and decoding mode,selection operation,crossover operator and mutation operator of chromosome,which makes the algorithm obtain PA finally Reto solution.Finally,based on the time information of the optimal processing route of each part family in the machining workshop,the scheduling example is analyzed and designed,and the NSGA-? algorithm is programmed with the help of MATLAB software to realize the simulation calculation;aiming at the multiple Pareto solutions obtained in the optimization stage,the AHP is used to help the decision-makers select the satisfactory scheduling scheme.The results show that the research in this paper is effective to shorten the completion time and reduce the production cost of the workshop.