Research On Balancing And Scheduling Optimization Of Bogie Mixed Model Assembly Line

In recent years,our country's rail transit industry has developed rapidly,and it has gradually stepped out of the country to enter the international market.With the continuous increase in the operating mileage of the rail transit industry,the demand for supplementary vehicles for different train vehicle types on various operating lines has gradually increased.Under this trend,the production model of bogies,which are the core components of train vehicles,has also changed from small varieties and large batches to multiple varieties and small batches.In order to meet market demands and improve production efficiency,the mixed-flow assembly lines will be gradually applied to bogie assembly production.The thesis takes a company's existing bogie mixed-flow assembly line as a research object,proposes an improvement plan for the shortcomings in its production status,and studies the balance and scheduling optimization of the parallel workstation bogie mixed-flow assembly line designed in the improved plan.Mainly completed the following aspects of work:(1)Analysis of the problem of bogie mixed flow assembly line.First,the production status of a company's bogie for mixed-flow assembly line was introduced,and through the process flow analysis of three different locomotive bogies on the assembly line,the deficiencies of the assembly line were found,and an improvement plan was proposed for the deficiencies.The key problems and difficulties in the improvement plan design were analyzed,and the corresponding research technical route was formulated.(2)Research on the balance optimization of the mixed flow assembly line about the parallel workstation bogie.Firstly,the initial model was constructed,and the correctness of the initial model structure was verified by using the correlation matrix method of Petri net.Then,the bottleneck of the initial model was analyzed and optimized by Flexsim simulation software.The mixed flow assembly line of the parallel workstation bogie was obtained.The setting plan of the number of parallel workstations in each processing stage in the last stage is compared with the evaluation index of the balance degree of the company's existing bogie mixed flow assembly line model.The results show that the parallel workstation bogie mixed flow assembly line model has a better balance effect and balance.The rate increased from the current 73.7% to 85.8%,the balance loss rate decreased by 12.1%,and the smoothness index decreased from the current 2002.2 to 706.4,a decrease of 64.7%.(3)Research on scheduling optimization of mixed-flow assembly line of parallel workstation bogies.First,the scheduling problem is described and a mathematical model for scheduling decision is constructed.Then,based on the balanced and optimized parallel workstation bogie mixed flow assembly line model,the improved PSO algorithm is used to design the scheduling model,and a minimum is solved by Matlab programming.Minimizethe maximum completion time of the production cycle,get the optimal product scheduling plan,draw the optimal scheduling Gantt chart,and at the same time compare the performance of the PSO algorithm before and after improvement,and finally pass the company's existing bogie mixed flow assembly line scheduling model A comparative analysis of the solution results shows that the parallel workstation bogie mixed flow assembly line model has better production flexibility and higher production efficiency.With the improved PSO algorithm for multiple operations,the average completion time in a minimum production cycle is 1099.7min shortened to 695.9min,a 36.7% reduction.