Optimization Research On Flexible Compositions And Multiple Service Routes Combination Mode Of Urban Rail Trains

At the end of 2021,the urbanization rate of China’s resident population was 64.72%,which means that the population structure has undergone a fundamental change,with more and more rural population turning into urban population,and there is a continuous upward trend.Therefore,many first-tier and second-tier cities have started to develop urban rail transport vigorously in order to relieve the pressure of urban roads,but the increasing passenger flow demand has brought a greater challenge to the operating enterprises.The existing mode of operation with fixed train compositions and single service routes can no longer adapt to the spatial and temporal changes in passenger flows.In order to solve the problem of uneven distribution of passenger flow in time and space,this paper proposes the optimization of flexible train compositions and multiple service routes combination mode to cope with the uneven time distribution of passenger flow by operating flexible train compositions at different times,and to cope with the uneven spatial distribution of passenger flow in the form of multiple service routes.The main work and research content of the thesis is as follows.(1)To explore the characteristics of metro passenger flow,based on the AFC data of Hangzhou Metro,analyze the spatial and temporal distribution characteristics of passenger flow after sorting,and verify the uneven distribution of metro passenger flow in different time periods of the same day,weekdays and weekends,as well as holidays and non-holidays,combined with the actual situation of the Hangzhou metro network to verify that the spatial distribution of passenger flow on each line is not balanced.On this basis,the time-space travel rules of passengers are statistically analyzed.(2)Analyzing the current train compositions system and service routes adopted by urban rail in my country,most of the lines still use fixed train compositions and single service routes operation mode,and a few lines adopt the operation mode of reconnecting compositions or multiple service routes,which shows that flexible train compositions and multiple service routes.The combination mode of the road is feasible from a technical point of view.In addition,from the perspective of engineering technology,the key technologies that control the combination mode are analyzed from the aspects of train control system,vehicle equipment,platform,screen door,station wiring,train moving-to-drag ratio and passenger information organization system.(3)Based on the principle of urban rail train running plan,a multi-objective optimization model is constructed to minimize the operating cost of the enterprise and the travel cost of passengers.In the passenger flow distribution module,the prospect theory is used to improve the logit passenger flow allocation model to better describe the psychological state of passengers when choosing a route.Therefore,it is applied to the distribution of OD passenger flow in the model,and the NSGA-II algorithm is used to solve the problem.The fuzzy membership function is used to decide the most satisfactory solution.(4)Through the comparative analysis of the results and the existing schemes,the optimal scheme increases the passenger time cost by 1.89%,and reduces the number of vehicles and vehicle travel distance by 7.46% and 8.65%,respectively.It shows that the combined mode can save the operating cost of the enterprise very well,but due to the application of multiple traffic routes,the time cost of passengers increases slightly.If the average increase is only 25 seconds per passenger,it can be ignored.In addition,comparing the section full load rate of the two schemes,it can be seen that under the premise that the average section full load rate is almost the same,the maximum section full load rate of the optimal scheme is 30% lower than that of the existing scheme,indicating that the optimal scheme is more feasible.In addition,Hangzhou Line 2 currently adopts the operation mode of large and small service routes during the morning rush hour,which further verifies the views proposed in this paper.