Research On Path Planning For Mobile Robot Based On Improved A~* Algorithm

Nowadays,the modernization,industrialization and automation of society have aroused the craze of robot research,which is considered to be one of the most important inventions of humans in the 20 th century.Especially,with the development of computer science and automatic control technology,robots have been widely used in many fields.In the aspect of industry,robots have almost done repetitive and heavy manual work in the factory for humans,in which the structured environment make it easy for mapping and path planning.Motion planning and trajectory planning are two important fields of robot mission planning.Motion planning includes path planning and path tracking.Path planning means to find an optimized non-collision path from the starting node to the target according to certain evaluation function.The performance of the planning algorithm is closely related to the complexity of the environment.A widely used path planning algorithm-A~*,by calculating the heuristic function value of each node and choosing sub-node with the smallest heuristic function value,search the optimal path from the starting node to the target.The main problems of A~* algorithm are time-consuming and storage-space consuming.Aiming at those disadvantages,an improved A~* algorithm was improved in this paper through comparing several widely used path planning algorithms and some improved A~* algorithms.Firstly,exponential function was used to weight the estimation cost of both current node and its parent node so that the algorithm could search forward to the target quickly when the current node is far away from the target and local search carefully when it is near to the target,which ensure the target is reachable even if the target node is surrounded by obstacles.Secondly,the generated path was smoothed by quintic polynomial so that it is convenient to control robot to track the path.Thirdly,through simulation experiments on MATLAB,comparing the runtime and path length of Dijkstra,conventional A~* and improved A~* algorithms,the improved algorithm in this paper have reduced the run-time,shortened the path length and eliminated the right corner turning point so that the robot could track the path without pausing and turning.Finally,the proposed algorithm was verified under maze environment.The result shows that the proposed algorithm can adapt to different environments and has a good real-time performance.