Path Planning Of Mobile Robots Based On A* Algorithm

Path planning has become one of the burning issues of robotics research with the rapid development of robot technology.Path planning not only needs to meet the demand to make robot process from the initial point to the target point smoothly,but also requires considering the condition factors such as time,distance,which should be optimized as possible.Since A* algorithm which has advantage of searching rapidly and easy to be implemented is a new heuristic searching algorithm,many researchers have been trying to use A* algorithm for solving path planning of mobile robots.While A* algorithm deletes some potential optimal nodes prematurely in earlier stage of heuristic searching and only has 8 neighborhoods when it extands,when A* algorithm is been used to solve the problem of mobile robot path planning,in many cases,the optimized solution is not the global optimal path,but one of the local optomal paths.Considering this shortcoming,this paper studies 2 mobile robot path planning methods based on improved A* algorithm in the mobile robot working environment which exists globally known static obstacles to improve disadvantages of traditional A* algorithm and plan a perfect path.In this paper,the contents of research includes the following aspects:Firstly,the length of path can't be the shortest when traditional A* algorithm be used for solving path planning of mobile robots as the reason that A* algorithm deletes some potential optimal nodes prematurely in earlier stage of heuristic searching and only has 8 neighborhoods when it extands.According to this disadvantage,the paper improves heuristic search strategy on the basis of traditional A* algorithm and extends the number of searching neighborhood from 8 discrete points to 24,so searching direction can be increased more.This improved algorithm is used for solving path planning of mobile robots,and contrasts with experimental data of A* and 44 neighborhoods A* algorithm to verify optimization of path length.Secondly,the paper raises Bi-directional 24 neighborhoods A* algorithm considering searching time of 24 neighborhoods A* algorithm is slower than traditional A* algorithm.The improved algorithm searches along the two directions and take the expanded best point as target point on the corresponding direction at the same time.Simulation results show that Bi-directional 24 neighborhoods A* algorithm can reduce path planning time successfully on the basis of length of path is shorter than traditional A* algorithm.These two improved A* algorithms for solving path planning of mobile robots can significantly improve the running efficiency of traditional A* algorithm and effectively overcome issues that the path length is not optimal and smooth,which has practical research significance.