Robot Path Planning Of Autonomous Walking And Space Operation

With the development of science and technology and artificial intelligence,robots have been widely used in space exploration,military reconnaissance,industrial assembly,agricultural picking,medical assistance and other fields,and the research on robot technology has increased.As one of the key technologies of robot,path planning can not only plan safe paths autonomously for the robot to ensure the successful execution of various tasks,but also can be used for the initial planning of the movement trajectory of the manipulator in space operation.However,some existing path planning algorithms have problems such as low search success rate,easy to fall into local extrema and poor obstacle avoidance ability in unstructured environments.Therefore,the study of path planning methods in complex environments can not only improve the adaptability of robots to different tasks and environments,but also have great significance to meet the needs of social automation and intelligent development.In this paper,the path planning method of robot autonomous walking and manipulator space operation in complex environment is studied as follows:Firstly,the global path planning of robot in complex static environment is studied.In order to solve the problems of poor directional random expansion and slow convergence in the later stage of RRT algorithm,this paper proposed an improved RRT algorithm with a Goaloriented mechanism and a random fluctuation strategy of target points based on the field investigation of orchard environment and the characteristics of orchard robot tasks.The improved RRT algorithm is compared with the RRT algorithm and an adaptive PSO algorithm in different simulation scenarios.The results show that the proposed improved RRT algorithm is superior to the RRT algorithm and the adaptive PSO algorithm,and allows the robot to walk autonomously in complex environments.Secondly,in order to solve the local path planning problem of robot in complex environment,an improved DWA local path planning algorithm based on fuzzy control is proposed.The weight coefficients and defects of the DWA algorithm are first analyzed,and then three fuzzy controllers are designed based on the principles of directionality and safety to achieve dynamic adjustment of the three weight parameters of the DWA algorithm.Simulation results in different scenarios show that the improved fuzzy DWA algorithm can avoid the emergency obstacles safely,and it has stronger adaptability to different environments Thirdly,modified D-H method was used to establish the kinematics model of the manipulator,and the forward and inverse kinematics of the manipulator were deduced and analyzed in detail.The forward and inverse kinematics simulation model of the manipulator was established by Robot toolbox to verify the accuracy of the forward and inverse kinematics solutions,so as to meet the different needs of the manipulator in space operation.Finally,the obstacle avoidance motion planning of manipulator is studied.In order to alleviate the problem of inefficient motion planning due to discrete grasping postures when grab objects of high-dimensional space in narrow environment,the concept of workspace target region(WGR)is used to provide a continuous and complete description of graspable region,and then the RRT* algorithm is used to plan the robot arm obstacle avoidance path.The path is smoothed using the "corner-cut" method.The simulation results show that the proposed path planning algorithm can effectively avoid the obstacles in the process of grasping and placing objects,and plan a reasonable path for the manipulator.