Design Of Fire Evacuation Simulation System Of Rail Transit Station Based On BIM,VR And Agent Model

Urban rail transit is an important means of public transportation in many large and medium-sized cities.However,the urban rail transit station is a closed space and the passenger flow in the station is often large.Once an emergency happens in the station,there may be serious consequences of casualties,and fire is the main type of accident.Therefore,it is necessary to conduct simulation research on fire accident in the station.The existing pedestrian model is mainly studied by means of microscopic simulation.Among them,the Agent model is one of the main microscopic pedestrian models due to its advantages of autonomy and adaptability.In traditional computer simulation studies,the simulation process is usually carried out from a third-person perspective with insufficient participation,and the research focus is generally on the behavioral characteristics of pedestrians,while the delicacy and authenticity of evacuation scenes are neglected.The workload of evacuation scene modeling is also large.In view of the above problems,this study is based on the widely used building information modeling(BIM)technology,virtual reality(VR)technology and Agent model to achieve high degree of reality of pedestrian emergency evacuation simulation,and through the integration of research results to develop VR emergency evacuation simulation system.The research was carried out from the following aspects,and the corresponding results were obtained:(1)Summarize the universal BIM modeling method.The method uses Revit as a software tool.The content includes station selection,data research,and Revit software modeling and selects the Beijing Metro Weigongcun Station as the target station for case application.(2)Load the completed BIM model into the VR engine Unity3 D,complete the docking work of BIM and VR in Unity,and realize the development work of docking the VR environment with external VR devices,providing technical support for the rapid VRization of the BIM model Save modeling effort.(3)Through the comparative analysis of relevant domestic and foreign norms,virtual fire scene is realized in VR scene,including fire location,available evacuation facilities,total number of people and allowable evacuation time,and two evacuation modes of general evacuation and evacuation guidance are set.(4)According to existing studies,pedestrians are divided into four categories: male and young adults,female and young adults,the elderly and children.Different model size parameters,speed parameters and perception parameters are assigned to each type of Agent.Through C# programming and the principle of finite state machine,the four states of the Agent in the whole process of evacuation are designed and realized,namely,Reaction state,Evacuation state,Reponse state and Arrival state.(5)Based on the development work of BIM,VR and Agent,integrate the research results,develop a VR emergency evacuation simulation system,test the realization effect of its VR and Agent sub-modules,and implement system case applications for actual engineering problems,Make optimization suggestions and verify the actual evacuation problems.The research combines the advantages of BIM and VR technology,and realizes more realistic pedestrian evacuation simulation by combining the Agent model construction.The VR system developed can also play its value in the field of scientific research and engineering application.