Optimization Research Of Urban Rail Transit Scheme Based On Large Passenger Flow State Identification

The Urban Rail Transit System is responsible for a large number of residents’travel demand,and congestion becomes a prominent problem during busy hours.When the capacity of the line can not meet the demand of the passengers along the line,resulting in heavy passenger flow at some stations,it will affect the service level of the line along the line and adjacent lines,reduce the travel efficiency and exist security risks.Therefore,this paper proposes an optimization model of Urban Rail Transit Operation Scheme based on the identification of the state of the large passenger flow,which can judge whether the station is in the state of the large passenger flow through the identification model of the state of the large passenger flow,in the case of large passenger flow station concentration,the paper studies the plan of large and small passenger flow,and improves the efficiency of large passenger flow in metro.The main research contents of this paper are as follows:(1)The paper reviews the existing studies at home and abroad from three aspects:the concept and characteristics of large passenger flow,the identification method of large passenger flow,the operation organization and the optimization of Operation Scheme,and describes the definitions of foreseeable passenger flow and unforeseeable passenger flow qualitatively,and according to the passenger flow,the occurrence time,the passenger flow constitution carries on the classification to the passenger flow.(2)The paper introduces in detail the contents of the train operation plan,analyzes one by one the influencing factors of the train operation plan of Urban Rail Transit,and introduces the basic compiling method of the train operation plan,which lays a theoretical foundation for the following research contents.(3)The paper analyzes the causes of the formation of large passenger flow and its propagation process,puts forward the identification basis of large passenger flow according to the influencing factors of large passenger flow,and on this basis,constructs the identification model of the state of large passenger flow,the model not only considers the passenger flow congestion of each station in the line,but also considers the passenger flow congestion of the line interval.The characteristics of large passenger flow are analyzed from macroscopic and microscopic perspectives,including macroscopic space-time characteristics,duration of large passenger flow,influence of large passenger flow on passenger flow and disequilibrium coefficient.(4)According to the analysis index△θ_i of the passenger flow variation Coefficient of the adjacent sections in a single period,the fluctuation range of the passenger flow in each section is quantitatively judged,by calculating the ratio of the section-to-section passenger flowθ_i and the section-to-section passenger flow△θ_i,the section with△θ_i greater than0.1 andθ_i greater than 0.5 is regarded as the high-density section of passenger flow,this paper presents the establishment of traffic type and the setting method of turn-back station in the case of large passenger flow station concentration.(5)An optimization model of train routing with the highest train carrying rate and the lowest total passenger waiting time under the matching condition of supply and demand is constructed,the model needs to consider the constraints such as the number of cars,the degree of congestion,the tracking interval time and the waiting time.In order to compare the operation effect before and after optimization,the section average full load rate,transportation efficiency,the number of passenger stations and the number of stranded passengers are selected as evaluation indexes.Finally,taking the section from South Station to Xujiahui of Shanghai Urban Rail Transit Line 9 as an example,the state identification of large passenger flow is carried out,and the optimized operation scheme is obtained by solving the optimization model of train routing,it is verified that the urban rail transit is more suitable for large and small intersections under the condition of the concentration of passenger flow stations.In this paper,by calculating the stranded passenger flow and the maximum capacity of the station,we judge whether the station is in the state of large passenger flow or not,and according to the train routing optimization model,we get the routing optimization scheme when the stations of large passenger flow are concentrated,it can provide a theoretical basis for the adjustment of Urban Rail Transit Operation Scheme under the condition of large passenger flow,and effectively alleviate the pressure of large passenger flow.