Research On Path Planning Of Indoor Mobile Robot Based On Improved A~* Algorithm And Dynamic Window Approach

With the rapid development of robot technology,mobile robot has been widely used in logistics handling,industrial transportation and so on.This paper takes four-wheel omnidirectional mobile robot as the research object,and improves the traditional A~*algorithm and the traditional DWA algorithm.In the global path planning algorithm,A~*algorithm is improved by combining skip search strategy and pruning strategy.In the local path planning algorithm,an improved DWA algorithm is adopted by combining global path and heading Angle optimization.Specific research contents are as follows:(1)Firstly,the common environmental modeling methods are analyzed,and the experimental environment is modeled by grid method.Secondly,the forward and inverse kinematics of the four-wheel omnidirectional mobile robot is analyzed.Finally,the feasibility analysis of the mobile robot path planning algorithm is carried out.(2)The principle and process of the traditional A~* algorithm are introduced.In view of the problems of long computing time and large memory occupation caused by excessive redundant nodes visited by the traditional A~* algorithm when planning the path,the skip point search algorithm is used to replace the access node of the traditional A~* algorithm.There are many transitions and path redundancy problems in the calculated path.The pruning algorithm was used to prune the path.The results of simulation experiments on multi-size maps show that the improved A~* algorithm shortens the path search time,reduces the path transition and shortens the path length.(3)The principle and evaluation function of the traditional DWA algorithm are analyzed.In order to solve the problem that the traditional DWA algorithm is easy to fall into the local optimal solution when following the global path,the evaluation subfunction close to the global path is added to the evaluation function,so that the path can better fit the global path and follow the global path to prevent falling into the local optimal.Aiming at the problem that the turning radius of robot is too large due to the influence of course Angle,a course Angle optimization strategy is proposed to effectively reduce the turning distance.Through simulation experiments,it can be concluded that the path planned by the improved DWA algorithm can not only avoid falling into local optimal,but also effectively solve the problem of path redundancy.(4)In order to verify the effectiveness of the improved A~* algorithm and the improved DWA algorithm,Gazebo simulation software was used in ROS to conduct realistic environment simulation and verify the feasibility of the improved A~* algorithm and the improved DWA algorithm.The actual mobile robot is used to build A raster map in the experimental environment,and the improved A~* algorithm and the improved DWA algorithm are verified experimentally in the static environment and the dynamic environment respectively,which further proves the feasibility of the improved algorithm in the actual environment.To sum up,aiming at the defects of the A~* algorithm,this paper proposes to improve the A~* algorithm to improve the speed of the planned path and remove the redundant parts in the path.Aiming at the problems existing in DWA algorithm,an improved DWA algorithm is proposed to strengthen the global path following and optimize the path during turning.The simulation results in Gazebo and the experimental results on the actual robot experimental platform show that the improved A~* algorithm and the improved DWA algorithm proposed in this paper can complete the path planning task of the robot in the actual environment.