Research On The Comprehensive Optimization Of Assignment And Maintenance Plan Of High-speed Railway EMUs

Due to the rapid speeding up of high-speed railways in China,the number of EMUs running on-line and the number of trains undergoing maintenance operations are increasing,and the characteristics of EMUs network utilization have become apparent.At the same time,as for the application and maintenance of EMUs,it is necessary not only to consider the basic constraints of maintenance,but also to meet the fluctuation of passenger flow in different periods.Therefore,the assignment and maintenance of EMUs in China is very complex and difficult to compile.In response to this problem,this paper has studied the optimization of the overall formulation of the application and maintenance plan of EMUs.First of all,based on the actual situation of EMUs assignment and maintenance management in China,the characteristics of maintenance management are summarized from the assignment mode of EMUs,maintenance management mode and maintenance regulation,and the relationship,influencing factors and internal capacity of the overall compilation of the maintenance plan are analyzed in detail.This will lay a foundation for the study of the overall optimization method of EMUs assignment and maintenance plan.Based on the theory of time and space network,the problem of assignment and maintenance of EMUs is analyzed,and the formulation of the plan is abstracted as a network problem.On the basis of determining the boundary conditions of the studied problems,a three-dimensional space-time network state map containing the EMUs state transition process was constructed based on the three main dimensions of EMUs assignment and maintenance,from the three dimensions of time,space and state.The basic idea of the integrated preparation of the EMUs maintenance plan was put forward.Secondly,through the construction of the time and space network of the assignment and the maintenance plan,each path of the EMUs in the space-time network is defined to express each work link in the planning cycle of the EMUs.Through the path combination scheme of the EMU,the EMUs assignment and maintenance plan are embodied.And based on the use efficiency and the reasonable maintenance plan of the train,the overall optimization model of the maintenance plan is established,which takes the train connection time and the least maintenance cost as the objective,considering the constraints of the maintenance system,the time and space constraints,the maintenance capacity and the number of spare motor units.Finally,based on the basic principle of the ant colony algorithm,the ant colony algorithm is used to generate the path of the EMUs,and the ant colony algorithm is designed from the general idea of the model constraint processing and problem solving.First,a small example is used to illustrate the problems and ideas of the research.Then a large scale example is designed and solved by ant colony algorithm.The results show that the method isvery effective and the speed of solving is very fast.However,with the increase of the problem,the efficiency of the solution is reduced,and the limitation of the time and space network itself is obtained.Under the condition that the number of EMUs is relatively small,this method can effectively utilize EMUs resources and improve the efficiency of EMUs.