Research On Terrain Recognition And Path Planning Based On Regular DEM

In disaster relief,in order to ensure the efficiency of rescue,shorten the arrival time and facilitate the relief work,it is necessary to choose a flat region around the disaster site as a workplace and plan a reasonable rescue route between the disaster site and the flat region.Although it is easy to search for routes based on electronic maps such as BaiduMap and GaodeMap etc,the disaster may destroy the roads,and these electronic maps may not performance roads in remote areas,which makes that the electronic maps can not provide the appropriate routes.At this point,finding a new route is the key to make rescue succeed based on digital elevation model(referred to as DEM).To solve the above problems,this paper based on the study of the existing flat region searching and pathfinding algorithms,to meet the needs of region searching and pathfinding in disaster relief,combining with terrain recognition,A* pathfinding algorithm and Geographic Information System(referred to as GIS),propose a flat region searching algorithm and a A* pathfinding algorithm based on DEM data.Meanwhile,based on the Java version of World Wind digital earth released by NASA as a secondary development platform,the region selection as workspace for rescue and rescue route planning software was designed and realized.The main work of this paper is as follows:(1)This paper use maximum all-one sub-matrix searching in 0/1 matrix algorithm to solve the problem of flat region searching.The thought is that,firstly,the terrain flatness calculation of DEM data in Region Of Interest(referred to as ROI)is performed using slope or elevation standard deviation.Secondly,generate the 0/1 matrix corresponding to the regular mesh DEM data by a given threshold.Finally,search the maximum all-one sub-matrix in that 0/1 matrix to get the flat region.(2)To solve the problem of path planning,a new A* pathfinding algorithm based on regular grid DEM data is proposed.In this algorithm,the distance and slope are used as indicators in the evaluation function.This paper designs this evaluation function,on the one hand,in order to eliminate the effects of distance and slope on different dimensions.On the other hand,meet a constraint,which is that the slope in the path should not exceed the maximum climbing capacity of the rescue equipments(vehicle)or rescue personnel.Under such a premise,the distance to the rescue route should be as short as possible.On this basis,this paper designs the dynamic calculation model of the complete function g(n)based on resolution of DEM,and further constructs the heuristic function h(n)based on slope and distance.Simulation results show that the newly constructed A* algorithm can quickly search out a suitable path in the huge DEM data,and has high searching efficiency.(3)Based on World Wind development platform,this paper designs and implements the prototype of disaster rescue planning software for disaster relief needs.The functions of this software includes data processing,flat region selection based on 0/1 Matrix,route searching based on newly designed A* algorithm,displaying the searched region and path in the form of 3D in the digital earth.