Integrated Optimization Of Line Plan And Train Timetable On Suburban Railway Based On Time-dependent Passenger Demand

With the accelerated urbanization in China,the population attraction of urban is rapidly increasing,while traffic congestion and other pressures are constraining the development of cities,so the centrifugal diffusion of urban population has become an inevitable trend of urban development at present.As a key transportation mode between urban and suburban,suburban railways play a crucial role in commuter travel.To promote the development of suburban railways,transportation efficiency of train timetable and line plan design have become bottleneck points for suburban railway’s resource allocation and transportation capacity development.Therefore,from the perspective of improving the transportation efficiency and optimizing the transportation organization of suburban railways,this paper proposes a method to optimize the integration of the train line plan and train timetable on suburban railways based on time-dependent passenger demand.The main contents are as follows.(1)The problem of integrating the preparation of train line plan and train timetable on suburban railway is analyzed.Firstly,this paper describes the functional positioning of suburban railways and the characteristics of commuter passenger flow.An analysis of the important contents of the train line plan and train timetable and the research improvement direction of these plans on suburban railways is proposed.Secondly,an allaround carving way of train running path and passenger traveling path based on time dimension and space dimension is proposed.Finally,this paper proposes the modeling method of integrated optimization of train line plan and timetable based on the discrete spatio-temporal network.(2)A 0-1 integer programming model for integrated optimization of train line plan and timetable on suburban railway based on time-dependent passenger demand is constructed.Firstly,the components and construction process of the spatial infrastructure network,train operation space-time network,and passenger assignment space-time network are explained,and the close relationship between the three networks is explored.Secondly,based on the space-time state network of trains and passengers,the integer programming model for integrated optimization of train line plan and timetable on suburban railway based on time-dependent passenger demand is finally constructed according to the multi-commodity flow model by minimizing train operation cost and passenger travel cost as the optimization objective function and considering the constraints of passenger flow demand,flow balance constraint,and safety.(3)A solution algorithm is designed based on the lagrangian relaxation and the alternating direction method of multipliers.First,according to the characteristics of the integrated optimization model,the lagrangian relaxation algorithm is used to decompose into the train operation subproblem and the passenger assignment subproblem for solving.Second,for the characteristics of the train operation subproblem,a solution algorithm based on the alternating direction method of multipliers is designed to efficiently solve the train space-time arc by updating the train variable blocks.Third,a dynamic programming algorithm for passenger space-time arc search is designed for a fast solution for the passenger assignment subproblem.At the same time,the parallel computational solution of the two subproblems is completed quickly and efficiently within the iterative framework of the lagrangian relaxation algorithm.Finally,the overall algorithmic framework and the solution process based on the lagrangian relaxation algorithm and alternating direction method of multipliers are described.(4)The feasibility of the proposed model and algorithm are verified with a suburban railway example.This paper has analyzed the optimized train line plan,train timetable,and convergence algorithm.By comparing with the integrated optimization results of the express-local stop scheme,it is proved that the integrated optimization model and algorithm can effectively meet the time-varying passenger flow demand of the suburban railway.And a feasible solution with better quality can be obtained within an acceptable time.This paper contains 37 figures,12 tables and 70 references.