Research On Optimization Model Of Train Stock Scheduling For Urban Rail Transit Based On Time-space Network

With the development of social economy,the urbanization process has been accelerating.So the scale of the city has been expanding,and people's daily activities have put forward new requirements for the development of urban public transportation system.As the core force of the urban public transportation system,the urban rail transit system is an important tool to solve the needs of large-scale passenger flows between regions.In recent years,the development of urban rail transit has been pushed to a new level.To meet the large-scale and high-quality travel demand,most cities are expanding their urban rail transit networks.At the same time,they are also striving to explore high-efficiency organizational operation models,and open up a way for the greenly and efficiently developing of urban rail transit system,to provide strong support for the healthy development of the city.Generally speaking,the formation of a complete operation mode must meet the needs of existing passenger flow.Then it should determine a reasonable train operation plan through research,and reasonably make the rolling stock scheduling plan according to the operation plan.As an important part of the urban rail transit system,the rolling stock utilization is an important factor affecting the overall operational efficiency.Under the conditions of different road network scales and passenger flow requirements,the optimization of rolling stock utilization based on the planned trains is not only rich in methods,but also valuable in improving the comprehensive benefits of operations.Therefore,taking the network operation mode as the research foundation,and focusing on the ownership relationship between the train rolling stocks and the car depot,,this paper studies the hot research problem of the rolling stock utilization and try to construct an optimization model of the train rolling stock utilization based on space-time network to enrich the optimization method system of the train rolling stock utilization.Based on the analysis of the development of urban rail transit,this paper discusses the formation and significance of the network operation mode.Meanwhile the relevant factors of the rolling stock utilization have been studied which aims at optimizing the urban rail transit operation.Based on the ownership relationship between the rolling stocks and the car depot,this paper analyses the characteristics of the train rolling stock utilization in the unfixed depot mode and the relevant influencing factors of the train rolling stock utilization plan,and clarifies the basic functions of various elements.From the perspective of the operator,this paper combines the network operation and space-time network,and analyses the model of train rolling stock scheduling for urban rail transit,which takes the minimum total operating cost as the optimization target.Then the uncertainty of ownership relationship between the rolling stocks and the car depot have been analyzed,and the optimization method of train rolling stock utilization has been further studied.At the same time,the basic characteristics of the model in the two modes are compared and analyzed.Due to the space-time network theory and the characteristics of the train rolling stock utilization model,the paper selects the Lagrange relaxation algorithm as the solving algorithm,and designs the solution framework of the two models separately.In addition,considering the actual operation situation,this paper combines with the basic functions and interaction of urban rail transit system,passenger flow system and external environment system,and sorts out the disturbance factors of rail transit operation.Then the causes and effects of time delay in operation organization process are analyzed,and the adjustment model of train stocks scheduling is constructed based on time delay.Finally,the method of adjusting the train stocks scheduling is put forward to eliminate the time delay,from the dynamic perspective,which provides reference for the actual operation organization.Finally,the paper analyses the case based on a network operation line of a city and the optimization effect of the two models that the ownership relationship of the rolling stocks and the car depot is certain and uncertain,analyses the adjustment of the train rolling stock utilization based on time delay,compares the value of two modes can bring in improving the comprehensive benefits of operation,and provides the development direction for optimizing the urban rail transit operation mode.