Research On The Optimization Of Electric Locomotives Maintenance Plan And Job-shop Scheduling Problem

With the rapid development of China’s railway,electric locomotives has become the main source of traction power for passenger and freight transportation.The maintenance of electric locomotives has the characteristics of high complexity,strict standard requirements,multi department cooperation,etc.it is the key factor to determine the safe operation and use efficiency of electric locomotives,which directly affects the quality and benefit of railway passenger and freight transportation.At present,the planned preventive maintenance mode with fixed cycle is widely used in the maintenance of electric locomotives.There is a certain disconnection between the maintenance content and the actual quality status of locomotives,which is easy to cause "insufficient maintenance" or "excessive maintenance";at the same time,due to the unreasonable process layout and work scheduling in the maintenance Job-shop,the maintenance time is prolonged,and the use efficiency of locomotives is reduced.Therefore,it is of great engineering value and theoretical significance to study the optimization of maintenance plan and content,the optimization of maintenance Job-shop process and scheduling,so as to make the maintenance work more scientific and reasonable,so as to further improve the maintenance quality and efficiency.In this thesis,based on the engineering value and practical significance of the optimization of electric locomotives maintenance plan and Job-shop scheduling,combined with the domestic and foreign research results and the problem reality,the idea of using intelligent algorithm to solve the problem is established.This thesis focuses on the optimization of the maintenance plan of the minor repair and the scheduling of the medium repair Job-shop1.This thesis defines the non ideal state of locomotives maintenance,introduces the two-stage delay time theory to describe the degradation process of components,establishes a mathematical model based on reliability constraints,adds the opportunity maintenance strategy to optimize the maintenance plan,and advances or delays the maintenance time of each component to achieve simultaneous maintenance,so as to optimize the maintenance cycle,reduce the number of downtime,and achieve The goal of minimizing unit downtime cost is achieved.2.This thesis analyzes and summarizes the work flow of medium maintenance Job-shop of electric locomotives,starting from the problems of extensive maintenance work and lack of macro organization and scheduling,taking the topological relationship of process and the assembly relationship of accessories as the main constraints,with the help of the idea of classic Job-shop scheduling problem,establishes the mathematical model with the minimum maintenance time as the optimization goal,and uses the improved ant with congestion degreeThe simulation results show that the model and algorithm can effectively improve the work efficiency of the Job-shop.