孙炜+吕云峰+唐宏伟+薛敏

摘 要：针对全局路径规划问题提出了一种改进的A*算法.首先，采用栅格方法建立环境模型，使用A*算法进行初步的路径规划.其次，针对A*算法规划的路径冗余点较多以及路径长度和转折角度较大的缺陷，提出将A*算法规划出的路径按较小的分割步长进行分割，得到一系列路径节点.最后，从起点开始依次用直线连接终点，当直线没有穿过障碍物时，则将中间路径点剔除，减小路径长度和转折角度.在仿真实验和实物实验中，分析和比较了本文算法与A*算法以及另一种改进A*方法.另外还研究了在不同障碍率、任务点数量和分割步长的情况下，本文算法与其他算法的优劣.结果表明，本文算法能有效地减小路径长度和转折角度.

关键词：移动机器人；路径规划；A*算法；栅格法

中图分类号：TP391.4 文献标志码：A

Mobile Robot Path Planning Based on an Improved A* Algorithm SUN Wei1， LV Yunfeng1， TANG Hongwei1，2， XUE Min1

（1. College of Electrical and Information Engineering， Hunan University， Changsha 410082， China；

2. Department of Electrical Engineering， Shaoyang University， Shaoyang 422000， China）

Abstract：An improved A* algorithm was presented for global path planning of mobile robot. Firstly， the environment model was described using the grid method， and the preliminary path was obtained by traditional A* algorithm. Secondly， the path planned by A* method was flaw with much redundant points， large path length， and turning angle. The original path was partitioned by tiny step to obtain a series of path point. The finish point from the start point was connected by using straight line in sequence. To decrease the path length and turning angle， the path node can be removed if there are no obstacles on the line. The analysis and comparison between the proposed algorithm， traditional A* algorithm and another improved A* method were then given in the simulation experiment and physical experiments. Additionally， the merits of the proposed algorithm and other algorithms were compared when the obstacle rate， amount of task point， and step length were different. The experiment results show that the proposed algorithm effectively reduces the path length and turning angle.

Key words：mobile robot； path planning； A* algorithm； grid method

路径规划问题一直是智能机器人领域的一个研究熱点.移动机器人路径规划是指机器人基于机载传感器获得的环境信息规划出一条从起点到终点的无碰、安全的可行路径，并在此基础上尽可能地优化路径[1].移动机器人路径规划主要解决以下三个问题：第一是规划出的路径能使机器人从起点运动到终点；第二是采用相应的算法使得机器人能够避开环境中的障碍物；第三是在满足前面两点要求的基础上，尽可能地优化机器人的运动轨迹，通常是以规划出的路径最短作为优化目标[2].根据机器人对环境信息的感知程度，路径规划问题分为全局路径规划和局部路径规划.前者是指机器人在拥有全部环境信息的基础上进行的路径规划，又称为离线路径规划；……