Research Of Structural Design And Obstacle Avoidance Path Planning For 6-DOF Robot In Constrained Space

Nuclear energy is a reliable and clean energy.With the sustained and rapid development of the nuclear power industry,the inservice maintenance tasks of nuclear power plants will also increase dramatically.The steam generator is one of the core equipment of nuclear power plant and is connected to the reactor pressure vessel through the main pipeline.During the overhaul of the nuclear power plant,temporary plugging of the main pipeline is necessary toprevent the damage of core fuel caused by foreign bodies entering the pressure vessel at the primary side.In order to reduce the radiation dose of workers and improve the efficiency of work,an operation mode of robot instead of human is proposed.However,the environment around the steam generator is very limited and necessary to avoid obstacles from the manhole of the steam generator water chamber.Based on this problem,a robot is designed and its obstacle avoidance path is studied.Firstly,according to the limited working space around the steam generator,a six-degree-of-freedom robot configuration for moving and rotating mixed joints is proposed.According to the work requirements and operating parameters,the joint structures of the robots are analyzed and designed,and the joints are the required drive motor,reducer and driver were selected and designed.The analysis software was used to check the strength of the robotic arm putter to achieve the working requirements.Secondly,the linkage coordinate system is established,and the kinematics is used to analyze the forward and inverse kinematics of therobot.The collision detection model of the cylindrical bounding box is established.The collision problem encountered in the actual operation of the robot was applied to the manhole wall of the robotic arm and the steam generator water chamber.The principle and steps of the step-bystep algorithm are introduced in detail and the step size is improved to fit the designed six-degree-of-freedom robot with moving joints and rotating joints.The collision detection model and the improved collision are added.The step size algorithm is combined to plan the obstacle avoidance path.Finally,using MATLAB and solidworks software,the virtual simulation model of the robot is established.The workspace of the robot is simulated.The cylindrical collision detection model of the robot arm and manhole wall is established.The programming is simulated by the obstacle avoidance path planning.The optimal step size is obtained by analyzing and comparing the simulation results,and the effectiveness of the algorithm is verified.