Dynamic Evacuation Method Of Multi-Targets Under Scene Constraints Based On Geometric Algebra

With the continuous development of the social economy,all kinds of emergency often occurs,which poses a great threat to the people's life and property security.The development of GIS technology has laid a foundation for using computers to simulate evacuation planning under emergency scene.However,Simulations based on computer technology need to abstract the complex multi-source/multi-type evacuation scene data,and integrate multiple constraints caused by data association in dynamic environment,which lead to difficulties for path planning in evacuation.Therefore,how to integrate and manage the evacuation scene data scientifically and efficiently to realize the evacuation path planning under dynamic environment has become a hot issue in the academic field.Geometric algebra is an algebraic system that uses algebraic language to express and solve geometric problems.It can express multi-dimensional geometries in unified expression,and has a reference for solving the organization and management of multi-type scene data in evacuation environment.At the same time,with the help of the rich computing operators in geometric algebra,it is helpful to better solve the problem of multi-objective dynamic path planning.In this paper,based on geometric algebra,a multi-source data integration and modeling method is proposed through multi-vector structure.Based on geometry and distance calculation,which shows the advantages of circle centers in the spatial distributions and spatial relations relying on correlation distance,the hierarchical index structure of circles was constructed to organize and manage the evacuation scene data.Based on the path expansion theory of geometric algebra,a heuristic routing algorithm expressed by geometry algebra was constructed.Combined with the circle index,the optimization of such routing algorithm was carried out.For emergency evacuation environment,a constraint system for path planning was constructed,and the updating method of scene index structure in dynamic environment was also proposed to study the multi-objective path planning problem in the dynamic environment.Finally,an experimental case was designed,and a visualization system for evacuation path planning and analysis was implemented.The research work of this paper mainly includes the following aspects:(1)Expression and organization of evacuation scene based on geometric algebra.According to the different data types in the evac,uation scene and the common data structure in GIS system,the method of integration and modeling of evacuation scene data based on geometric algebra was built.Based on the division of circles and the spatial features,the hierarchical structure of the evacuation scene was constructed,and the unified organization and management of evacuation scene data was implemented.(2)Optimal path searching algorithm based on geometric algebra.Relying on geometric algebra path expansion theory,the geometric algebra expression of heuristic algorithm was proposed,and the path expansion process was optimized combined with the constraints system and circle index.(3)Dynamic path planning under scene constraints.The multi-constraints system and the dynamic updating method of circle indexes were constructed,and the dynamic path planning of the multi-target was implemented by the heuristic searching algorithm.Based on geometric algebra,the integrated modeling method and organization model of scene data were constructed in this paper.Then,the heuristic searching algorithm was expressed by geometric algebra and optimized by circle indexes.Based on such two aspects,the dynamic path planning of multi-objective evacuation under constraints of the emergency environment was implemented.It may have reference value for the simulation of evacuation under the emergency environment.