Dynamic Planning Of High-rise Building Fire Rescue Path Based On BIM And Improved A~* Algorithm

With the improvement of the world economy,urban land area is becoming more and more rare.In order to achieve maximum economic benefits on limited land and better meet people’s living needs,more and more high-rise buildings have sprung up.High-rise buildings have brought new challenges to the fire rescue of high-rise buildings because of their high layers,complex internal structure,dense personnel and many combustibles.How to combine the ever-changing technology and information technology with the theme of fire evacuation to form a smart fire protection system that meets the characteristics and requirements of the times has become a research hotspot.Based on the BIM three-dimensional model,this paper attempts to simulate the scenario of high-rise buildings after fire in Pyrosim software to obtain relevant data.On this basis,the A~*algorithm in path search is improved from three directions to generate the best path of fire rescue.In order to give full play to the characteristics of BIM visualization,combined with the secondary development technology of Revit,the path generated by Matlab is tried to be displayed in a three-dimensional manner in the Revit model,which provides a new display window for the intelligent fire protection results.The main research contents of this paper are as follows:Firstly,a high-rise building fire protection model based on BIM is established.This model makes up for the lack of materials and other parameters in the modeling process of Pyrosim software,so as to restore the fi re scene more truly and conduct simulation analysis based on it.With the passage of fire time,the temperature,visibility and smoke concentration of the fire scene at different times are quantitatively analyzed,which provides a reference for the subsequent fire rescue path planning.Secondly,the traditional A~*algorithm is improved to generate fire rescue path.Based on the advantages of traditional A~*algorithm in path search and the characteristics of high-rise building fire scenarios,the traditional A~*algorithm is improved in three aspects:(1)The search method of A~*algorithm is improved,and the search direction of traditional A~*algorithm is improved to bidirectional search,so that its computational efficiency is greatly improved.(2)The multipath pruning strategy is introduced to simplify the search direction of the original algorithm,so that the search direction of the original method is improved from eight directions to four quadrants,which reduces the traversal of useless nodes and improves the calculation speed.(3)The generated path is smoothed by Freud’s algorithm,and the jagged path nodes are removed to make it more consistent with the actual firefighters’search and rescue.Finally,the three-dimensional visualization of evacuation path is realized by Revit secondary development.With the characteristics of BIM technology visualization,the planned rescue path is displayed in a three-dimensional building model through the secondary development technology of Revit.On the one hand,it provides convenience for firefighters to read drawings and helps them better understand the structure of the building and the direction of the rescue path.On the other hand,it provides a reference for the correlation research between Matlab and Revit software.