Research On Coordinated Optimization Of High-speed Railway Timetabling And EMU Circulation Scheduling

In the organization of high-speed railway operation,the train diagram and EMU circulation schedule are the keys to reducing internal operating costs and improving service levels.The traditional process of planning the train diagram and then planning the EMU circulation schedule cann’t guarantee the quality of both at the same time.Therefore,it is necessary to set up an integrated planning process.Optimize the quality of train connections during planning the train diagram,increase the utilization rate of EMUs,and reduce the number of operating EMUs.In the field of transportation organization,the coordinated optimization of the train diagram and the EMU circulation plan has important theoretical and engineering significance for reducing the cost of EMU operating and improving the efficiency of passenger services.In this paper,the following four aspects of the research about the coordinated optimization problem are as follows:(1)Systematic analysis about coordinated optimization problems is the theory of train diagrams and EMU circulation schedules.Analyze the influencing factors,general model and compilation traditional process of train diagrams and EMU circulation schedules.And analyze the mutual influence between the train diagrams and EMU circulation schedules,propose an integrated compilation process,then compare it with the traditional process and feedback adjustment process.Finally summarize the advantages of integrated compilation process and coordinated optimization.This paper also summarizes the objective functions and constraints that need to be considered in the coordinated optimization model.(2)Establish a coordinated optimization model of the train diagram and EMU circulation schedule based on the train connection network and time-space-state network.The optimization problem is transformed into the vehicle routing problem through the train connection network.And the parameters and variables in the model are discretized,and the solution scale is reduced through the time-space-state network.The main objective functions are to optimize the total travelling time of the trains,the number of EMUs and the first-level maintenance cost,and then consider the objective function of the balance of the operating miles of the EMUs.The constraints of the model is the least train arrival and departure interval time,the service uniqueness,connection time and EMU’s first-level maintenance.A calculation example of 8 trains was designed and solved with GAMS.The results proved the correctness of the coordinated optimization model.(3)A solution algorithm based on Alternating Direction Method of Multipers(ADMM)is designed.Analyze the decomposability of the model,reconstruct the model using the alternating direction multiplier algorithm,and relax the augmented Lagrangian of the complex constraints involving the coupling relationship of multiple trains to the objective function,and linearize the quadratic penalty term.The original problem is decomposed into sub-problems of single EMU routing optimization,and the model solving is accelerated.Design the upperbound solution of the ADMM algorithm,the lowerbound solution of the LR,the sub-problem solving of the forward dynamic programming algorithm,and the algorithm parameter update process.Solve solve the cases of train nodes of different sizes,and compare them with the calculation indicators of the LR and GAMS to verify the feasibility and high efficiency of ADMM algorithm.(4)Large-scale case study.Finally,sign the actual Beijing-Tianjin intercity high-speed railway and Beijing-Shanghaihongqiao high-speed railway network cases to solve the optimization problems.Calculate the number of EMUs,the utilization rate and other indicators,compare with the actual situation,in order to verify the adaptability and effectiveness of the model and the algorithm.With 43 figures,34 tables and 61 reference literatures.