Research On Path Planning Technology Of High-degree-of-freedom Mobile Robot Considering Vehicle-manipulator Coordination

With the development of technology in digital workshops and unmanned factories,it is difficult to meet the new production needs of the robot arm with fixed base,and the development of the robot arm with movable base has attracted much attention.The combined high-degree-of-freedom mobile robot combining the mobile platform and the robotic arm inherits the mobile platform's mobile performance and the robotic arm's operating performance,and is highly reconfigurable,which can reduce production costs and improve production efficiency and flexibility.Existing motion planning methods mainly use decentralized planning for a single mobile platform or robotic arm,making it difficult to apply to complex operating environments.Therefore,it is of great theoretical value and practical significance to study the motion planning of high-freedom mobile robots coordinated by vehicle arms.The thesis studies the path planning of high-freedom mobile robots.The main research contents are as follows:This paper introduces a high-degree-of-freedom mobile robot system,analyzes the kinematic characteristics of the manipulator,establishes the kinematic equations of the manipulator,and establishes a high-degree-of-freedom mobile robot system model.According to the operating environment characteristics and task requirements of the mobile platform and the top loading robot arm,different expressions of the operating environment are adopted.A path planning method for mobile platform based on improved A * algorithm is proposed.By analyzing the target constraints,obstacle constraints and vehicle arm constraints that exist when the mobile robot arm is integrated,the obstacle map and Delaunay triangulation are used to preprocess the environment map to ensure the safety and randomness of the planned path Aiming at the problem of slow convergence of the A * algorithm in complex map environments,a method of constructing Open List using priority queues is proposed,and dynamic weighting is performed on the heuristic function to achieve rapid convergence of the algorithm;combining linearization processing and cubic Hermite The interpolation method post-processes the path to achieve the effect of smoothing the path.The simulation test of the proposed path planning method verifies the efficiency and superiority of the proposed method.A motion planning method for bodywork manipulator based on improved RRT algorithm is proposed.The influence of the docking error of the mobile platform on the motion planning of the bodywork arm is studied,and the error compensation measures based on coordinate conversion are given.The shortcomings of the RRT algorithm in complex maps for motion planning are analyzed.Regarding the problems of the RRT algorithm's slow convergence and easy to fall into local search in complex maps and narrow channels,a regression filtering mechanism is proposed to avoid repeated node expansion and reduce collision The number of detections improves the convergence speed of the algorithm.Aiming at the characteristics that boundary nodes have a large probability of expanding invalid nodes,a random point boundary expansion mechanism is proposed to reduce the number of invalid node expansions and greatly shorten the number of robotic arm collision detections.In the tunnel environment and the labyrinth map environment,the proposed robotic arm motion planning method was simulated and tested to verify the effectiveness and efficiency of the proposed method.In this paper,the overall framework and software system architecture of the highdegree-of-freedom mobile robot working system are constructed,and the path planning module of the mobile platform is designed and implemented.Finally,experiments were carried out on the mobile platform and the robotic arm to verify the feasibility of the proposed method.