Research On Mobile Robot Path Planning Based On A* Algorithm

In recent years,the robot industry has developed rapidly and has been widely used in various industries,gradually affecting the production and life of society.Mobile robots have the characteristics of autonomous movement and flexible movement,and have widespread application and development prospects in industrial production and domestic services.The core of the mobile robot is the robot path planning.An efficient path planning algorithm can enable the mobile robot to quickly plan the optimal path and ensure the safety and stability of the robot movement.At present,there are many path planning algorithms,and the A* algorithm is more intelligent and widely used.This thesis mainly studies the A* algorithm,optimizes the improved A* algorithm and combines it with the improved dynamic window method.The effectiveness of the fusion algorithm is verified by matlab simulation and the Hawkbot mobile robot platform.The research in this thesis is as follows:1.In view of the problem of low search efficiency and long path of A* algorithm,firstly,the search neighborhood of A* algorithm is expanded,from the traditional 3*3neighborhood to 5*5 neighborhood;Secondly,the A* evaluation function is adjusted;Finally,the path planned by the improved A* algorithm is optimized by extracting key nodes.The path length planned by optimized and improved A* algorithm is reduced by2.165%,time is reduced by 47.233%,Path nodes are decreased by 69.697%,the inflection point of path is decreased by 27.273%.2.Aiming at the problem that the dynamic window method is easy to fall into the local optimum,the path evaluation function is dynamically adjusted.When the distance is far from the obstacle,the proportion of the moving direction is increased;when the distance is closer to the obstacle,the proportion of the moving speed is increased,so that the robot can quickly approach the target point.The improved dynamic window method reduces the search time by 13.41%.3.Aiming at the problem that the path planned by the optimized and improved A*algorithm is not smooth enough and cannot achieve dynamic obstacle avoidance,the optimized and improved A* algorithm is combined with the improved dynamic window method to form an improved fusion algorithm.Specifically,the optimized and improved A* algorithm uses the improved dynamic window method according to node segments.The path planning of the improved fusion algorithm is reduced by 2.19%.4.The proposed improved fusion algorithm is verified in the actual environment.First,we build the actual mobile robot Hawkbot,and use the YDLIDAR-X2 lidar to scan the environment information to build an environment map in Rviz,and then conduct experiments.Through experiments,it can be seen that Hawkbot can avoid obstacles and reach the target point according to the improved fusion algorithm.Compared with the traditional fusion algorithm,the planned path is smoother.The research techniques and methods adopted in this thesis also have certain reference value for readers to improve the path planning algorithm of mobile robots.