Research On Job Scheduling Of Multi-workshop Mixed Assembly Line Based On Improved Discrete Particle Swarm Optimization

China's manufacturing enterprises of finished automobile began to learn and introduce Toyota Production System(TPS)in the 1980 s,but the actual production effect of most vehicle manufacturing enterprises is not ideal.Under the production mode of Just In Time(JIT),it has been a research topic for academia and business circles to realize the high-efficiency production of mixed assembly lines in multiple workshops.The job sequencing problem of multi-workshop mixed assembly lines is a kind of complex combinatorial optimization problem.When making production plans,enterprises should consider not only the production process and organization mode of products,but also the supply of spare parts.In this paper,Faw Jiefang Automotive Company is taken as the background to study the job sequencing problem of mixed assembly lines.Firstly,the mathematical model of the job scheduling problem of mixed assembly lines is established.The job sequencing problems of mixed assembly lines includes the problems under JIT production mode and multichannel buffer area.Based on the sequencing problem of mixed assembly lines in JIT production mode,the mathematical model is established by production load balance of assembly shop,leveling of material consumption and switching times of painting color in the painting workshop.Based on the sequencing problem of mixed assembly lines in multi-channel buffer area,the mathematical model is established by production load balance of assembly shop,leveling of material consumption and number of channels in a multichannel buffer areas.To solve the sequencing problem of mixed assembly lines,an improved discrete particle swarm optimization is proposed based on DPSO,and the concept of population pool is proposed.Replace the method of optimal individual particle leading the population with that of particles in the population pool leading the population.By referring to the crossover strategy in the genetic algorithm,the way of information interaction between particles was improved and update mode of particle location is changed.Combined with Simulated Annealing(SA)algorithm,the local search ability of the improved discrete particle swarm optimization algorithm is enhanced.The improved discrete particle swarm optimization algorithm is used to solve the sequencing problem of mixed assembly line in JIT production mode and the validity of the algorithm is verified.This paper discusses the structural characteristics of multi-channel buffer area,studies the sequencing method of mixed flow operations based on multi-channel buffer area by combining the improved discrete particle swarm optimization algorithm and heuristic rule set,and verifies the effectiveness of the improved discrete particle swarm optimization algorithm in optimization problems of solving combination.By optimizing the number of channels in the multi-channel buffer area,the influence of the number of channels on the sequencing ability of the multi-channel buffer area is discussed.Finally,taking the truck manufacturing workshop of Faw Jiefang Automotive Company as the background,the operation sequencing system of mixed assembly line is developed by using GUI tool in MATLAB software.First,the system is to solve the sequencing problem of mixed assembly line jobs in single workshop and multiple workshops under JIT mode.Second,it tends to solve the sequencing problem of mixed assembly line jobs in multi-channel buffer area.The human-machine interface of the system is simple and easy to operate which can offer help for dispatcher...