Research On Urban Rail Transit Network Timetable Scheduling Strategy

Scheduling urban rail transit timetable is a complex systematic optimization problem.It is to achieve optimized indexes with the demand of the passengers and a series of constraints of train resources(e.g.number of trains,cost of use),running speed,minimum headway,maximum and minimum station dwell time.Throughout the development of urban rail transit network,many researchers had been working on developing efficient timetable scheduling theories and methods.In general,these studies are in two aspects:single-line timetable scheduling optimization;network timetable synchronization.Focusing on the core idea of meeting passengers' demands,the purpose of single-line timetable scheduling optimization is to schedule a detailed timetable to minimize passengers' waiting time at each station in the same line,while the purpose of network timetable synchronization is to minimize passengers' waiting time at interchange stations by coordinating and synchronizing different lines.The widely-used Auto Fare Collection System in urban rail transit offers a mass of data about passengers' demands,which is the basis of scheduling efficient and accurate timetables.Based on the passengers' demand,this paper studies in depth the single-line timetable scheduling optimization and network timetable synchronization.As far as single-line timetable scheduling optimization is concerned,this paper presents an optimized model of passenger waiting time and minimum line congestion timetable based on passengers' time-variant demands.This model system takes station capacity,train capacity and passenger waiting time into consideration.And it finds its solution by establishing multi-objective optimized function of minimum waiting time and station congestion,and by multi-objective optimization method based on genetic algorithm.An empirical analysis of the model based on actual data shows that the model can evidently reduce passengers'waiting time.And compared with some existing half-regular and irregular line timetable scheduling methods,this model can effectively cut down congestion events.As for the network timetable scheduling,this research models network timetable synchronization with multi-line departing time,running time,and headway as its control variables,establishes an objective function with minimum link-up time of all trains as its target,and optimizes it based on the genetic algorithm.For example,the result of empirically analyzing Nanjing Subway Network shows that the model can reduce trains' connection time at interchange stations compared with existing regular timetable scheduling methods.The text structures of this paper:The first chapter states the background and significance of researching urban rail transit network timetable scheduling strategy,and gives an overview on the current situation of this research and future development tendency of this subject.The second chapter systematically introduces some basic theories about timetable scheduling around the topic of spatial-temporal distribution characteristics of passenger flow,scheduling model,optimizing targets and its method.The third chapter presents a timetable optimization model of minimum passenger waiting time and line congestion based on passengers' time-variant demands;formulates a multi-objective optimization method based on the genetic algorithm to solve timetable scheduling problems,verifying it and its mechanism through practical cases.The fourth chapter discusses timetable synchronization optimization in network timetable scheduling.The fifth chapter summarizes the results of the research in this paper and gives prospects on timetable scheduling strategy researching.