Optimization Research Of Single-line Cooperative Flow Control Strategy In Urban Rail Transit

Currently,with the ever-increasing scale of urban rail transit construction in China,passenger volume continues rising.As a result,passenger flow congestion has become one of the major factors that affecting the operational safety of urban rail transit regarding the continuous impact of the increasing passenger flow.The adoption of reasonable measures is the most effective measure to ease congestion and to ensure operational safety.However,in actual operation,the formulation of the passenger flow control measures mostly rely on the subjective experience of the station staff,which somehow lack of a quantitative method to restrict the flow strategy and the coordination between stations.Therefore,from the aspect of urban rail transit,it is of great significance to study the quantitative formulation methods of single-line coordinated flow control strategies.In the basis of the theory and method of urban rail transit passenger flow control,this study analyzes the main influencing factors of the single-line coordinated flow control strategy;meanwhile,it builds a single-line coordinated flow control optimization model for urban rail transit.To optimize the single-line coordination of urban rail transit flow control strategy,we also take Beijing Batong subway as a case study.The specific research content is as follows:(1)The analysis of passenger flow control theory of urban rail transit and single-line collaborative flow control strategiesThis paper summarizes the passenger flow control theory of urban rail transit from the necessity of passenger flow control and the level of passenger flow control.It builds a single-line multi-station service system based on passenger travel behavior.Based on this,our study analyzes the single-line cooperative flow control strategy from the aspects of the connotation,influencing factors and common methods of single-line collaborative flow control.Given the passengers total waiting time,the total passenger travel time and the station flow rate indicator,we evaluate the effectiveness of establishing a single-line coordinated flow control strategy.(2)Establishing of an optimization model for coordinated flow control of urban rail transitThis chapter will express the indicators of the single-line multi-station service system in mathematical way.We establish a single-line coordinated current limit for urban rail transit using the number of flow-limiting units at each station entrance as the decision variable,minimization of the passengers' total travel delay time as the goal.The optimization model is based on passenger travel behavior at the station entrance,train location information,passenger boarding and boarding behaviors,and single-line multi-station service system capabilities as the constraint expression.The design is based on the improvement of the stochastic proportional operator perturbation simulated annealing algorithm(SAA)to search model optimal solution.(3)The parameter calibration and algorithm verification of single-line collinear flow control optimization modelBased on the single-line coordinated flow control optimization model,a small-scale five-station single-line system was constructed and accurately solved by using CPLEX software.The setting of the penalty coefficient of delay time in the model was analyzed from the constant term and expression of the penalty coefficient respectively.Moreover,the model is calibrated for the best control effect for stations in the entire line.We also study the impact of passenger traffic congestion at station platforms on the development of single-line coordinated flow control strategies,and to analyze the impact of single-line coordinated flow control strategies on passenger travel,taking changes in passengers' total travel delay time into account.The improved simulated annealing algorithm is used to solve the problem,and the results are compared with the exact results obtained by CPLEX to verify the practicality and accuracy of the design algorithm.(4)Optimization research on flow control strategy for Beijing Batong subwayWe take the stations of the Beijing Batong subway during morning peak hours(7:00 a.m.?9:00 a.m.)in the descending direction(Tuqiao station-Sihui station).The optimized simulated annealing algorithm was used to build the single-line collaborative flow control optimization model.This model compares the optimized single-line coordinated flow control strategy developed with no-limit flow control measures to verify it.It can reduce passengers' total travel delay without causing passenger loss as well.At the same time,it can also realize the identification of delays for passengers at all stations,and allocate more train residual capacity to control stations with higher passenger flow congestion.We verify the feasibility and optimization of the model.