Research On Passenger Movement Patterns In Subway Stations Based On Cellular Automata Mode

The subway has the advantages of high speed,large capacity,low noise and low pollution.It is the preferred means of transportation for most urban residents.However,due to the limitation that subway stations are mostly built in closed underground space and the particularity of passenger movement in the station,the problem of passenger evacuation under emergencies has become increasingly prominent,which has become one of the hot issues in the current research.The current research mainly focuses on the route selection of passengers evacuating to the exit during the peak passenger flow or emergencies in the station.There are relatively few studies considering that the point of emergencies is in the subway carriage.The research on the whole movement process of passengers leaving the carriage and then choosing the stair/escalator/elevator to evacuate to a safe area is not enough.Based on the microscopic cellular automata model,combined with fuzzy logic theory and logistic model,this paper establishes the passenger dynamics model to study the pedestrian evacuation in the subway station,the selection of passenger stair/escalator/elevator,and the modeling of passenger movement behavior in the stair area.The details are as follows.Firstly,a passenger evacuation movement model based on improved cellular automata model is proposed to analyze the rule of passenger evacuation movement in case of sudden emergency in subway train carriage.Under the influence of the instinctive response of passengers to seek advantages and avoid disadvantages in the face of emergencies and the herding psychology,the selection mechanism of carriage doors during passenger evacuation is constructed by using the fuzzy logic theory,and the motion model of passengers is established based on the cellular automata model.The simulation experiment is used to analyze the influence of the occurrence point of the emergency,the effective utilization width of the door and the seat layout in the carrage on the evacuation efficiency.The following simulation results are obtained.The evacuation efficiency of passengers is the highest when the fire occurs in the middle carriage,compared with that occurs in the first carriage or the last carriage.The overall evacuation efficiency of passengers could be improved in a certain range with the increase of the effective utilization width of the door.It is recommended that the seats be arranged in a single row longitudinal way,which can not only bring comfortable traffic experience to passengers but also enable all passengers to leave the carriage with high evacuation efficiency in case of emergency.Secondly,a passenger stair/escalator/elevator selection model in subway station is proposed to study the selection behavior of passengers from platform floor to concourse floor based on cellular automata model and fuzzy logic theory.Fully considering the two factors of the distance between passengers and the stair/escalator/elevator and the density of passengers,a passenger stair/escalator/elevator selection mechanism is established with the help of fuzzy logic theory.Through the simulation experiment,the relationship between different numbers of passengers/escalators,passenger speeds and passenger evacuation efficiency is analyzed,and the following conclusions are obtained.The number of passengers who choose escalators is more than that who choose stairs and elevators.The number of passengers who choose stairs increases with the increase of the initial number of passengers,but the number of passengers who choose elevators does not change significantly.Increasing the number of escalators can reduce the time required for passengers to leave the platform floor to a certain extent.When the number of passengers is moderate,the increase of passenger speed is conducive to the overall rapid departure from the platform floor.Finally,a cellular automata model based on logistic model is established to analyze the motion rules of subway passengers in the ascending staircase area.Considering the destination expected by passengers when climbing the stairs,the route choice of other passengers and their own walking preference,the transfer probability formula in the cellular automata model is improved based on the logistic model,and the model parameters are corrected with the help of SPSS.The actual motion trajectory of passengers in the field data is extracted with Tracker software,and the verification of the model is completed by comparing the actual motion trajectory with the simulation trajectory.Through the simulation experiment,the following conclusions are obtained.The more passengers in the ascending staircase area at the initial time,the longer it takes for all passengers to leave the stairs.Properly increasing the length of stairs and steps can effectively improve the evacuation efficiency.When the number of descending passengers in the ascending stairs increases,the overall evacuation efficiency could be reduced.