The Study On Timetable Optimization For Urban Mass Transit Network Operation In The Last Train Time Period

Urban railway transit is the main bearer of urban commuter traffic,the main carrier of mass travel and an important support for the nonnal operation of the city.So far the urban railway transit system of most big cities have developed from a single line to a crisscross railway transit network.Under the condition of network operation,how to coordinate and compile timetable for last trains in the network is one of the key problems to be solved urgently.This paper synthesizes the relevant research results at home and abroad,analyses the features of last train time period--which refers to the time period starts at a particular moment after the evening rush and ends at the end of operation--under the condition of network operation,and does an in-depth study on the timetabling problem of last trains for urban railway network.The specific research contents are as follows:First of all,this paper investigates the current methods of last train timetable compilation in the representative urban railway transit system in China and discusses their applicability,advantages and disadvantages.On this Basis,this paper carries out an in-depth analysis on the characteristics of passenger demand,the features of operational organization and the process of transfer connection during the last train time period and studies the key factors that affect the timetable compilation for last trains.Then,according to the characteristics of urban railway transit,a simplified topology modeling method for urban rail transit network is proposed.Based on the synthesizing of existing last train timetable compilation models,this paper builds the general model for last train timetable compilation which sets the goal as "maximum the transfer flow"in order to optimizes the connection between last trains in the network.Furthennore,the period during the end of evening peak and the end of operation which to be called the last train period has a few characteristics such as the sparsity of passenger flow,large headway and long transfer waiting time.Due to all the characteristics,if the network timetable wants to work out good,it must be compiled with a comprehensive consideration of enterprise operation income,passenger transfer cost and other factors.Based on the above,this paper proposes the timetable compilation model for the last train period,which is no longer limited to the simple optimization of the connection between last trains of each line in the network,but aims at coordinating all the trains in the network and achieves the best optimal during the last train time period.After that,genetic algorithms and genetic simulated annealing algorithms are designed respectively to solve the two models which are based on analysis of the characteristics and difficulties of the two models.What's more,the basic theories of genetic algorithm and genetic simulated annealing algorithm are explained and the implementation process and operation steps of the algorithms are showed in detail.Finally,a real case which is in medium scale is designed to prove the validity of models and algorithms and to compare the differences,advantages and disadvantages between the models.In this case all the passenger flow data and network data are actual and real,and three methods--GAMS,genetic algorithm and genetic simulated annealing algorithm—are used to solve the two models.Besides,a case that is in large scale is designed to prove the applicability of the models and the efficiency of the algorithms in large scale,and to show that them can provide a meaningful reference for the timetable compilation of urban railway transit network at the same time.