A VR-based,Multi-Granularity Modeling Approach To Fire Evacuation Simulation

Fires are the catastrophic problem in the world.Typically,evacuation simulations can raise pedestrians safety awareness and reduce the risk caused by fires.However,the majority of models used in simulations can't simulate homogeneous high-density crowd,self-organizing phenomena and individual deversity behaviors simultaneously.Hybrid techniques are therefore proposed,however,original problems still exist and new efficency issues could be generated.Besides,current evacuation models usually focus on static spatial information but lack dynamic event perception and adjustment capabilities.This paper explores to realize comprehensive and efficient real-time simulation while using immersive VR environments to improve the user experience.The main contributions are:· We propose a multi-granularity modeling and simulating approach.The multi-granularity evacuation model consists three optimized submodels: dynamical network flow model,agent-based model and social force model.They will deal with the global crowd movement,self-organized phenomena and individual deversity behaviors.Besides,the model uses the heuristic algorithm in the global and local relationship together with the Voronoi Diagram in the local areas in order to achieve effective coupling.· We propose an optimized smoke diffusion prediction model and realize smoke influences on pedestrians.Meanwhile,we also design an emergency response mechanism driven by parameters extracted from external videos depending on the evacuation model.The emergency module will first simulate fire accidents according to parameters and then start an evacuation routine or adjust evacuation plans dynamically.· We design a configurable protype system in VR environments.After evaluations and analysis,the proposed modeling approach have been proven to be effective for comprehensive simulation.Meanwhile,users can experience the evacuation in VR environments with full immersive and visual experience.In summary,the proposed modeling and simulating approach can make the fire evacuation simulation more realistic and improve model efficiency in VR environments simultaneously.