Combinatorial Optimal Method Of Routing And Formation On Urban Rail Transit

The operation of urban rail transit, as a mass transit mode, is closely related to the demand of passengers. In practice, the passenger flow between peak period and flat period is quite different and it is a common phenomenon of the mismatch in supply and demand. Operation effect is vary form different train routing scheme and train formation scheme, research of them can optimize using of train resource, to achieve the optimization of service level and operating cost. The main research contents and conclusions are listed as following:The paper analyzes the influence factors of train routing scheme and train formation scheme from two dimensions of operators and passengers, puts forward the limiting factor in the configuration of vehicles, and analyzes the relationship between the operating cost and service level. The relevant research results of literatures are sorted out to study the shortcomings and applicability of the preparation method of train routing scheme and train formation scheme.The principle and framework of combinatorial optimal method of routing and formation are put forward on the analysis of the influencing factors and compiling methods.The optimized targets of model are considered form passengers and operating company. Waiting time and the degree of congestion is taken seriously by almost passengers, and operating cost and difficulty of operation organization are important for operating company. The multi-objective function is transformed into a single objective function by two-phase method based on AHP and fuzzy theory. The constraint conditions of model are considered form many factors, such as the line transport capacity, the interval time of trains, the configuration of vehicle, the number of routing, and the number of different trains. Finally, a modified multi-population adaptive genetic algorithm is designed to solve the model.Several cases were used and analyzed to justify and explain relevant results. Initially, Beijing Subway Line 12 is solved as an example, two schemes are respectively obtained, scheme one adopts full-part route and multi-formation and scheme two adopts full-part route and single formation. They are compared with the scheme of single route and single formation. Two scene are built and solved based as the deviation of actual traffic and forecast passenger flow, outburst mass passenger flow. The former proves that the configuration of vehicles will be a major limiting factor to meet roaring passengers. The latter proposes some adjustment measures for outburst mass passenger flow. Furthermore, the OD data of virtual line are constructed based on B.P.R. model, the impact of different average travel distance and direction of mass passenger flow is studied for train routing scheme and train formation scheme.