Real-time Path Planning For Safe Rescue In Building Fire Based On BIM And CA

In the event of a fire in a building,firefighters are often required to enter the indoor environment for fire fighting and rescue.Due to the lack of understanding of the internal structure of the building and the impact of the spread of the fire field,firefighters were unable to find the best real-time rescue paths,and may not be able to find the best rescue paths in real time.The lack of effective real-time rescue paths guidance not only greatly reduces the rescue efficiency of firefighters,but also greatly threatens the life safety of firefighters.Nearly 20 firefighters are sacrificed in building fire rescue every year in China.BIM technology can build a building model consistent with real buildings,and provide a real three-dimensional building environment.The cellular automata model(CA)has been widely used in the research of personnel evacuation as a new discrete model,which can better simulate pedestrian motion characteristics.A real-time planning system of firefighter rescue paths based on BIM and CA is proposed in this paper,which can provided technical support for the development of fire prevention and rescue strategies for building fires,efficient and accurate rescue,and intelligent fire protection to relevant departments.An intelligent and universal CA path planning intelligent model is proposed,which can automatically identify various components and internal environment of the building.Use C # programming language to write “Grid” script and “PathPlan” script,which uses scene stratification and collision detection methods to automatically identify the various components and the internal environment of the building,and divide the single-storey building and multi-storey building evacuation grid.A BIM building model of a single-story large-space gymnasium and a BIM building model of a multi-story small-space office building were established by using Revit.By designing various building components and giving corresponding materials,fire resistance coefficient and other characteristics,the BIM building model has a consistent information database with the real building,so as to truly simulate the internal environment of the building.A fire rescue path real-time planning system based on BIM and CA path planning intelligent is developed in Unity 3D.Realize the layout of the fire scene by placing fire models,obstacle models and fireman models in the building.The“DynamicGridObstacle” script is written by using the C # programming language to realize dynamic obstacles and random catastrophic functions.In order to simulate the dynamic real-time adjustment and planning of the rescue path in the real fire sceneenvironment,the dynamic obstacle model and random catastrophe fire model are added to the fire field to study the real-time influence of the dynamics of the fire field on the rescue path.The script is written in C # programming language to realize the2 D or 3D intelligent division of the grid,intelligent generation of firefighters,intelligent generation of obstacles,multi-point real-time monitoring system,small maps,fire sound effects,and "Rover" models.The fire rescue path real-time planning system was used to simulate the fire rescue path real-time planning for the gymnasium and the office building.The simulation results showed that,(1)The five firefighters in the gymnasium can plan the optimal rescue path in real time according to the spreading fire field,and all firefighters have been evacuated from the fire safely within 126 time steps(about 34seconds).(2)Nine firefighters in office building can plan the optimal rescue path in real time according to the spreading fire field,and all firefighters have been evacuated from the fire safely within 219 time steps(about 59 seconds).The simulation results of two engineering cases show that the fire rescue path real-time planning system developed in this paper is suitable for the simulation of the fire rescue path real-time planning of single-story and multi-story buildings.