Research On Theory And Method Of High-speed Railway EMU Circulation Plan Optimization

The construction of high-speed railway has been revolutionizing the technology and equipment of China's passenger railway transport.The networked features of China's high-speed railway are becoming prominent increasingly.As the most important operational equipment,although there have been fruitful research results that EMUs have achieved efficient turnover under the conditions of line-forming,with the change of the allocation of transportation resources,the continuous development of the high-speed rail management system,the emergence of the new EMU management mode,some new problems have been emerging in EMU utilization management problem and it is necessary to carry out targeted researches under consideration of the real situation.The EMU utilization problem is to study and analyze different management measures and modes that can improve the efficiency of EMU(including EMU's allocation method,operation mode,maintenance mode,and backup mode),combined with China's high-speed railway management mechanism,EMU management and operation characteristics,etc.,considering the selected EMU management mode,and EMU maintenance mileage and time limitation,type restriction of EMU maintenance,maintenance capability,night accomodation capacity,train tasks implementation as constraints,to optimize the EMU utilization efficiency and balance maintenance tasks assigned to each depot by routing,assigning and maintainning the EMUs.There are a series of problems in the EMU's circulation planning paroblems.The mainly existing problems are:(1)The EMU operation management modes' quantitative research that are suitable for China's characteristics need to be carried out.At present,China's railways have established a relatively complete system of EMU maintenance and operation.However,most of the theoretical researches are mainly based on the generation of feasible solutions of EMU circulation plans.For the relevant alternative management modes,the fixed EMU backup mode andthe EMU's first-level maintenance that does not return to the affiliation and another management mode,etc.,have not been fully quantified.The impact of these different management modes requires further research.(2)The existing EMU circulation planning based on the scheduled train timetable has stricter restrictions on the relevant factors,and the problem solution space is also strongly restricted.The effect of optimizing the EMU number and maintenance tasks is not obvious.(3)There are still insufficient consideration in the existing EMU circulation plan optimization model.(4)Most methods of the domestic research are heuristic algorithms.The optimization algorithms are used in domestic research,because the EMU uses the complexity and scale of the optimization problem.Although the heuristic algorithm can find a satisfactory feasible solution in a short time,their design and implementation have strong dependence on specific problem parameters,so the algorithm abstractness and scalability are weak,and the ability to find excellence solution is difficult to guarantee.In view of the above shortcomings,this paper mainly have researched the following:(1)Based on different railway transportation management conditions,there are certain differences in the EMU utilization and management in research and practice at home and abroad,this paper firstly analyzes the theoretical research and practice in the field of EMU utilization problems.Compared with other countries,the special restrictions in the EMU circulation plan in China's railway transportation organizations are summarized.Based on this,note that the existing researches have certain shortcomings and inadaptability and we specifically proposes the theoretical method based on the branch-and-price approach for solving the EMUs management modeling problem by group uses.(2)Based on the theoretical basis of relevant foreign research,considering the resource allocation of China's high-speed railway,the characteristics of train operation and the operation management mode,under the given conditions,the needs of EMU maintenance,the shortcomings in the actual situation and The EMU circulation planning process in the network environment are analyzed.The EMU operation management mode considering the characteristics of China's high-speed railway and the capacity allocation structure is provided for the optimization of the EMU circulation plan.With the above-mentioned key factors as constraints,the effective technical method route to save the EMUs number,reduce unnecessary EMU maintenance tasks and balance the EMU maintenace capability use,so that the proposed EMU circulation planning method is more suitable for the actual production needs,and the optimization model of the EMU circulation planning can overcome the shortcomings of previous studies lacking sufficient consideration in complexity of the maintenance factors.(3)Currently,the supply of EMU and other related resources are in short.When the new high-speed railway line is built and put into operation,it will affect the allocation of network resources by re-programming or adjusting the train operation timetable and EMU circulation plan according to the new high-speed railway network conditions.The problem of this research is that some lines must consider the restrictions of EMU resources during the train timetable scheduling.This paper mainly research on how to improve the efficiency of EMU from the perspective of transport enterprises and proposes an optimization method based on the given train timetable,which is different from the conventional method.The fixed train schedule are given to optimize the EMU.The main optimization objective is to reduce EMUs number used and the EMU's maintenance tasks with consideration of train travel time and so on.(4)In order to verify the feasibility and effectiveness of the proposed model and method,a case study on the EMU ciculation planning for Beijing-Shanghai high-speed railway was carried out,and the related results has been analyzed.