Research On Fire Evacuation Path Planning In Historic District Based On Intelligent Algorithms

With the rapid economic and social development,historic districts have gradually developed into comprehensive districts integrating tourism and commerce,which has brought many fire safety hazards to historic districts.Buildings in historic districts are mostly brick-wood structures,with large fire loads,low fire resistance levels,and small fire separation distances between buildings,which makes the fire easy to spread.The safe evacuation of people is the key to reducing casualties.The streets and lanes of historic districts are small in size and the road layout is complicated.When a fire occurs,tourists who are not familiar with the block environment can hardly choose an effective escape path,which increases the detention time of the trapped people in the fire.It is even possible to enter the fire blocking area.Therefore,how to make people in a fire accident escape safely and quickly from the environment of the historic block is an important issue for emergency evacuation of the historic block.The main contents of this paper are as follows:(1)Analyze the characteristics of fire in historic districts and the characteristics of evacuation of people,explore the main causes of fires in historic districts,and analyze the causes of fire disasters in historic districts from three levels: building,district,and management.The factors affecting the safe evacuation of people were analyzed in various aspects,and the crowd density,roadway difficulty,temperature and CO concentration were determined as the main factors affecting the evacuation of people,and they were quantified.(2)Establish a path planning model that takes into account the factors affecting the evacuation of people in historic districts.In the model,the equivalent length is used to replace the geometric length in the traditional algorithm.In view of the problem that the traditional grid map will cause the calculation of the algorithm to be too large when modeling the historic block,the establishment of the grid The evacuation network formed by the obstacle vertices grid in the grid map is used as the solution space of the ant colony algorithm.The heuristic function of the ant colony algorithm is improved by introducing the target point information and the path equivalent length,and the method of simplifying the redundant path is used to improve the ant Deadlock processing strategy,and use this method to further optimize the evacuation path,and use the firework explosion operator to optimize the local section of the evacuation path to improve the local search ability of the ant colony algorithm.(3)Establish a model of fire spread in historic districts based on cellular automata.The model uses a hexagonal grid to replace the traditional quadrilateral grid to avoid the inconsistency in the time dimension of fire diffusion simulation and evacuation path planning,and the problem of evacuation paths obliquely penetrating the wall;the hexagonal cell space is used as the environment The model uses the intelligent water drop algorithm to solve the safe and reliable shortest evacuation path.Since cultural heritage such as historic districts and ancient buildings have high historic and cultural values,improving the safety of evacuation and evacuation in such areas cannot destroy their historic authenticity,life authenticity,and integrity of style and features.The intelligent evacuation system planned as the core technology is an effective method to improve the evacuation efficiency of people in historic districts.