Development And Experimental Research Of Virtual Reality Platform For Passenger Evacuation In Urban Rail Station Fire

Urban rail transit has been vigorously developed due to its advantages of large transportation capacity and high punctuality.As the operating mileage of China’s urban rail transit has steadily increased,its operational safety has attracted important attention.Looking at the safety operation accidents of urban rail transit,the frequency of fire accidents is relatively high.Due to the narrow underground space,saturated passenger flow and limited access to the outside world in urban rail transit stations,once a fire accident occurs,the casualties and economic losses caused are immeasurable.Most of the related researches on the evacuation of fire passengers in urban rail transit stations use numerical simulation methods.However,because it is difficult to obtain the real behavior characteristics of passengers in the fire environment,the reliability of the simulation results needs to be further verified.In recent years,the rise of virtual reality technology(VR)and the concept of metaverse have provided effective research ideas for the study of passenger evacuation in urban rail transit stations.Simulating the occurrence of fire in a virtual environment can more realistically observe the escape of passengers.It also provides effective means for emergency drills and training in operating stations.In view of this,this paper conducts in-depth research on fire simulation,pedestrian micro-simulation and virtual reality,and then develops the "Urban Rail Transit Station Virtual Reality Emergency Drill Platform".Research on fire evacuation characteristics of passengers in traffic stations.The specific research contents are as follows:First,the basic theory of fire development,fire numerical simulation theory and fire smoke toxicity model are deeply studied in this paper.Based on the fire development characteristics,a quantification method for fire smoke toxicity was established.Based on fire theory and pedestrian evacuation algorithm research,a pedestrian dynamic path model considering fire evolution is proposed to simulate the movement characteristics of pedestrians around the fire.Secondly,taking the National Library Station as an example,the station fire simulation is carried out,which provides sufficient data support for the research and development of the virtual reality platform.According to the reaction time of the station staff and the strategies adopted when a fire occurs,the fire simulation scenarios are divided into the situation of timely extinguishing,the situation of not extinguishing the fire in time and the situation of abandoning the extinguishing.Based on the above three situations,Revit and Pyrosim are used to construct the finite element model of the National Library Station,and the fire evolution law of the degree of smoke spread,visibility,temperature and carbon monoxide concentration inside the station is deeply studied.Finally,the fire evacuation is analyzed and studied through the available safe evacuation time index by combining all the data.Thirdly,combining the above fire simulation results and the local algorithm of human-fire interaction,the UI,logic framework and function framework of the platform are designed.Based on the result data of fire simulation and development environment with the help of the Unity3 D and 3ds Max rendering tools,the scene of the National Library Station is completed.The "Urban Rail Transit Station Virtual Reality Emergency Drill Platform" was built and developed to provide technical support and an experimental platform for the study of passenger fire evacuation characteristics.Finally,based on the virtual reality emergency drill platform of urban rail transit station,a real-life experiment is carried out to study the passenger evacuation characteristics of station personnel corresponding to different fire-fighting situations in the state of sudden fire at the station.Design the experiment reasonably and determine the appropriate investigation and research method to analyze the experimental data,and finally analyze and discuss the result data for escape efficiency,injury degree,path selection and personal characteristic indicators.The results show that(1)the fire extinguishing situation cannot significantly affect the passenger escape efficiency.(2)The injury rate of passengers who give up the firefighting situation is low.(3)Different fire situations cause different degrees of mental stress to passengers,but the firefighting situation cannot significantly affect the passenger’s route choice.(4)There is obvious herd mentality in the process of passenger evacuation,which can guide the evacuation behavior of some people with high risk preference value.