Integrated Train Scheduling And Rolling Stock Circulation Planning For Metro Lines With Variable Train Composition

At present,trains are operated with fixed composition in most of metro lines of China.However,with the refinement of metro operation management and time-space variances of passenger flow characteristics,the traditional train operation with fixed train compositions is difficult to satisfy the following requirements,i.e.,improving passenger service level and reducing the operation cost.The metro operation with variable train compositions can adjust the length of trains flexibly and provide a high service frequency to achieve the accurate match between passenger demands and transport capability based to the various time-space characteristics of passenger flow.This paper studied the integrated train scheduling and rolling stock circulation planning for metro lines with variable train composition,investigated the potential of variable train composition for metro lines,and provided some guidance for the practical application of variable train composition.This paper mainly includes the following four parts:(1)The development status of urban rail transit system is analyzed and the problems that are faced in the train operations with fixed compositions is summarized.The feasibility and necessity of the train operations with variable compositions are demonstrated based on the existing literature on the train scheduling and rolling stock circulation planning for metro lines.Moreover,the concepts of train scheduling are summarized,where the key point of the train scheduling problem is the accurate match between the transport capability and the unbalanced passenger flow in time and space.(2)The integrated model of train scheduling and rolling stock circulation planning with the operation of variable train composition is constructed.By analyzing the process of coupling and decoupling operations,the resulting optimization problem is a mixed integer nonlinear problem,where the new characteristics in dwell times,headways,etc.of the variable compositions are considered.The model can be solved by CPLEX solver by applying the linearization properties.The case study is carried out based on the line and operation data of Beijing Daxing International Airport Express.The computational results are shown that the operation with variable train compositions could meet the passenger flow demand better and reduce the number of waiting passengers,when compared with the fixed train composition and multiple train composition.(3)A solution algorithm based on Lagrangian relaxation is designed for the integrated train scheduling and rolling stock circulation planning problem.Due to the computational complexity of the integrate model,only some small-scale cases can be solved by the CPLEX solver.Therefore,a Lagrangian Relaxation based algorithm is developed to solve the large-scale cases efficiently.A case study based on the line and operation data of Shanghai Metro Line 16 is designed to demonstrate the effectiveness of the algorithm.For some cases,the relative error of upper and lower bounds can be converged on less than 1% by the Lagrangian relaxation algorithm.In addition,the influence of the different temporal and spatial passenger flow distribution is evaluated for metro lines with variable train operations.The results showed that the trains could be coupled or decoupled at nearby stations to adapt to passenger flow variations during the transition period between the peak and off-peak hours.However,if the passenger flow is too big and concentrated within a short period,it tends to that the coupling and decoupling operation is only appeared at the starting or ending stations of metro lines.In this case,the coupling and decoupling operations at the intermediate stations take a relatively long time,the headways between train services will be affect and the number of waiting passengers at stations is raised to a higher value.(4)The integrated train scheduling and rolling stock circulation planning problem is investigated for multiple lines that are operated jointly.Different forms of joint operation are summarized in this paper and are divided into two types,i.e.,the extension of branch line that is at the end of the main line and the extension of branch line that is not at the end of the main line.The integrated train scheduling and rolling stock circulation planning problem with variable train composition for the scenarios of joint operation is studied in this paper,where the relationship between different line structures of joint operation is analyzed and the constraints around the transfer station is modified.The effectiveness of the model is verified for the different line forms of joint operation.In addition,the computational results are shown that when the coupling/decoupling operation time is short,the headways between trains in the branch line can be reduced to meet the passenger flow demand better.However,if the operation time is too long,the variable train composition operation in the transfer stations and other intermediate stations cannot benefits the operation of trains in metro lines.There are 45 figures,18 tables and 71 references included in the thesis in total...