Research On The Theory Of Passenger Flow Assignment And Control Technology In Urban Rail Transit Network

In order to solve the contradiction between supply and demand,this paper optimizes and adjusts the demand of passenger flow and puts forward an optimization method that first allocates the network passenger flow and obtains the passenger flow of each time segment,thereby improving the service level of the road network,reducing the operation risk of station and improving the traveling quality of passengers.Around the theory of urban rail transit network passenger flow assignment and controlling technology,this paper mainly completed the following research work:(1)The passenger flow distribution is performed to distribute the network passenger flow of time-segment to the effective path.The time segment is the interval between two train leaving the station adjacently,and the passenger flow of time segment during the OD period is the passengers who enter the platform at each time segment.Taking the travel time,transfer time,and the number of transfers as the general travel expenses of the passengers,the shortest path between the OD pairs and the minimum general travel expenses are calculated.Under the condition that both the relative threshold and the absolute threshold are satisfied,the effective path and the generalized cost of all OD point pairs are solved by the ergodic algorithm of the breadth first.The improved Logit model is used to calculate the selection probability of each valid path between passengers of each OD point pair,and finally to obtain the passenger flow on each effective path.(2)Constructing virtual line and virtual running line,matching the passenger flow of timesegment allocated to the effective path to the virtual running line.The line that is included in the effective path is connected to the virtual line by transfer arcs between transfer stations.Combined with the transfer time,the operation lines of each line on the virtual line are matched,so that the virtual running line is obtained,and finally the train diagram of the virtual line is formed.When the effective path belongs to part or all of the virtual line,the time period passenger flow of the valid path is matched to the virtual running line,so as to obtain the line passenger flow-timetable network of the virtual line.(3)Building the passenger flow control model is based on the passenger flow-timetable network of virtual line.Taking the maximum passenger turnover as the objective function,the passenger flow entering station in the time period as the decision variable and the time segment OD passenger flow demand as the input parameter.The passenger flow cooperative control optimization model is established under the constraint of train capacity,the capacity constraint of the platform,the passenger flow demand constraint and getting on and off passenger flow.(4)Take the metro network in Chengdu as an example,choose the morning peak passenger flow of a working day for example analysis.First of all,the early peak is divided into time interval,and the OD passenger flow of time-segment is obtained.According to the improved Logit model,the network passenger flow is allocated to the effective path.The effective path is matched with the virtual running line to get the line passenger flow of the virtual running line,and the line passenger flow of the virtual running line is also the input parameter of the flow control model.The commercial optimization software CPLEX is used to compile and solve the flow control model,and the optimization results are consistent with the actual situation,which proves the correctness and effectiveness of the flow control model.