Research On Buffer Time Layout Optimization Method Of High-speed Railway Train Timetable

Train timetable is a train operation production plan for railway transportation enterprises to realize train safety,on-time operation and economical and effective organization of railway transportation.High-speed railways take safety,comfort,convenience,punctuality and reliability as their main competitive advantages to attract passenger flow.The timetable fulfillment directly affects the order of railway transportation organization and the quality of passenger service.However,in the process of train timetable implementation,there will be external interference,which makes the train arrival or departure time deviate from the timetable.It is an important means to improve the punctuality rate by reserving some buffer time in the train timetable to make it have good resilience.However,excessive buffer time will reduce the train travel speed and the utilization rate of transport capacity.Therefore,under the condition of limiting the total amount of buffer time,it is of great theoretical and practical significance to study how to allocate the buffer time,that is,to optimize the layout of the buffer time in the high-speed railway train timetable,to improve the timetable resilience,ensure the order of transportation organization and strengthen the advantages of high-speed railway passenger transport.In view of the limitations of existing studies,this study proposed two innovations:one is to establish a buffer time layout optimization model considering time window constraints to reduce the influence of the optimized timetable on other train path lines in the extended section and time period of the original train timetable;the other is to propose a train timetable simulation method based on the initial delay backtracking to increase the authenticity and rationality of interference scenes in the simulation process.This study,firstly,analyzed the disturbance and delay phenomena of train operation,derived the connotation and definition of train timetable resilience,and puts forward the premise of the study.On this basis,the resilience evaluation index of train timetable is established,and the realistic evaluation and experimental evaluation methods of elasticity are proposed.Then,the study analyzed the effect of buffer time of train timetable on improving the resilience,designed and put forward the optimization method framework of buffer time layout.The core of the framework is the buffer time layout optimization model considering time window constraints.Based on the SRCPSP theory,this model takes the optimization of the resilience evaluation index as the objective function.On the basis of the feasibility and security constraints of the train timetable,it considers reducing the influence on other train path lines,and adds the time window constraints.An improved greedy algorithm is designed to solve the model.Another important part of the framework is train timetable simulation based on initial delay backtracking.This study uses Markov chain to simulate the impact of train arrival and departure time fluctuation caused by drivers’ driving behavior,designs the simulation method and simulation process,proposes the method of tracing initial delay from the actual historical data of train operation,and uses the initial delay to fit the interference distribution.The interference scene library and generation method are designed to improve the authenticity and rationality of simulation.Finally,taking the train timetable of Beijingnan-Jinanxi section of the Beijing-Shanghai high-speed railway as an example,the full application of the train timetable buffer time layout optimization method was used to verify the validity of the time window constraint,the comparison and evaluation of the train timetable resilience,the validity of the optimization method was verified,the common optimization results was calculated,and the specific suggestions on the buffer time layout were given.There are 53 figures,25 tables and 81 references.