Study On Optimization-based Control Of Passenger Flow Distribution In Subway Stations

The subway station is the distribution point of larger amount of passengers in subway network.The operation and management of subway station experiences more and more difficulties along with the expansion of subway network and the increasing traffic demand.In order to improve the service quality of subway station,it is very significant to ensure the ordered passenger distribution under the limitation of facility capacity.Therefore,the subway station has been taken as the research object in this paper and the orderly control and uncertain interaction based location method of guidance signage in subway stations and the control models of passenger flow in corridors and subway stations are proposed to satisfy the intelligent management and the level of service requirements of passengers based on the previous studies.The main content of this paper is as follows:(1)Orderly control and uncertain interaction based location planning method of guidance signageAt first,a new and quantitative method to evaluate the ordering efficiency of signage systems and the guidance demand of pedestrians is proposed.Based on the phased interaction characteristics between passenger and guidance signage,the uncertain interaction model between passenger and guidance signage,which can be describes as a piece-wise probability function,is firstly proposed.The interaction between one passenger and one signage was extended to the interaction between crowd and signage system,the location optimization problem is simplified to a supply-and-demand issue.A location model of the guidance signage system was proposed to determine the minimum number of signs necessary to meet guidance demands.The location model was based on the Cooperative Location Set Cover Problem(CLSCP)and was correspondingly solved by a proposed exponential binary heuristic search algorithm(EBHS),i.e.,a combined exponential binary search method and a heuristic search algorithm for solving the Cooperative Maximum Cover Location Problem(CMCLP)..Finally,the proposed model was applied to determine the location of the guidance signage system on the station platform.The parameters used in the location model were calibrated based on experimental data.The model results showed that the proposed model can suggest the optimal number and best locations of signs.A sensitivity analysis showed that the guidance capacity of the signage system can be increased by improving the attractiveness of signage and passengers’ familiarity with environment.Because the microscopic passenger movement model and the interaction between the passenger and signage are incorporated into the proposed model,the model can be considered a general signage system location model.(2)Optimization-based control model of passenger flow in walkway of subway stationIn order to study the control method of passenger flow in walkways of subway station,the fundamental diagram of bidirectional pedestrian flow is derived from the unidirectional pedestrian flow by using the social force model under the uniform state.The walkway is divided into many sections due to the unequal passenger distribution.The model is proposed to simulate the passenger flow in unidirectional and bidirectional walkways.The control objective is calculated based on the fundamental diagram of pedestrian flow and the linear feedback control model of passenger flow is proposed.The static and dynamic control gain strategy(SK and DK)are proposed based on the linear characteristics of the proposed model.The proposed control model can maximize the passenger flow of corridor by adjusting the walking speeds of pedestrians and the inflows of the corridor in real time and thus avoid the blocking of passenger flow in corridors.The control efficiency of DK is proved to be higher than SK.(3)Level of service based hierarchical control method of passenger flow in subway stationIn order to satisfy the passenger flow control demand,the passenger distribution model of subway station is built based on the cell transmission model,and then the calculation method of control objective of passenger flow is proposed based on the level of service(LOS)concept.Finally,the hierarchical control method(HCM)of passenger flow which integrates the network flow control model(NFCM)and local flow control model(LFCM)is proposed.The NFCM is proposed to finds the optimal link inflows to ensure the number of passengers in the facilities satisfy the LOS requirement.However,the NFCM may lead to the non-uniform link density because the minimal control unit of NFCM is the facilities in passenger distribution network.In order to satisfy the premise of NFCM,the link flow control model(LFCM)is proposed to adjust the walking speed of passengers to realize the uniform facility density.Finally,the proposed HCM is applied in the passenger flow control of subway station and the model results shows that the HCM can find the optimal passenger inflow to meet the LOS requirements of subway station.The proposed model has high computing efficiency and the control results can be well accepted.The proposed model can provide support and decisions about crowd control for managers of subway station,and at the same time,the proposed model can promote the intelligent development of subway station and provide theoretical foundation for the construction of intelligent subway station.