说明：  基于距离转换的栅格地图路径规划方法,DT方法是从目标位置反向搜索路径。在栅格化环境中，从目标位置开始的距离传播视为一个波(wave front)沿空闲栅格传播。对于环境中任意给定的起始点，其到目标点的最短路径可通过使用最速下降法搜索而得到。
(Raster map conversion path planning approach based on distance, DT reverse the search path from the target location. Distance from the target location in the grid environment, spread as a wave (wave front) along the idle grid dissemination. Starting point for any given environment, the shortest path to the target point by using the steepest descent method of searching.)