Research On Key Technologies Of Nuclear Facility Decommissioning And Waste Disposal Robots

Nuclear is an important part of energy.Due to the existence of radioactivity,nuclear environment has great harm to human body.Therefore,the operation in nuclear environment strongly depends on teleoperation or automatic operation.Robots are good choices for realizing teleoperation and automatic operation in nuclear environment.With the development of nuclear industry,the demands for decommissioning of nuclear facilities and disposal of nuclear waste are increasing,which requires robots to have high radiation resistance,easy decontamination ability,good maintainability and highprecision motion control performance.Based on this background,this dissertation studies the configuration design and the kinematic control method of robots systems under typical nuclear environment.In addition,the vibration suppression problem of flexible joint manipulator and the dynamic adaptive control problem of dual manipulator cooperative operation with task space constraints,which may existed in the previous configurations are studied.According to the configuration of 7-DOF manipulator and 9-DOF robot,the key technologies of mechanical system design and environmental adaptability are studied,and the prototype development and performance and function test are carried out.Firstly,the configuration of the robot is designed for the typical operation scenarios of nuclear facilities decommissioning and nuclear waste disposal,including 7-DOF manipulator,9-DOF robot and muti-degrees obstacle avoidance robot.Based on POE theory,forward and inverse kinematics control methods of 7-DOF and 9-DOF manipulators are established.Aiming at the inverse kinematics problem of muti-degrees obstacle avoidance robot,an inverse kinematics control method of muti-degrees obstacle avoidance robot based on polynomial curve fitting is proposed.The rationality of the kinematics algorithms of the three kinds of robots is verified by MATLAB simulation.Next,aiming at the vibration problem of the muti-degrees obstacle avoidance robot proposed above,the vibration suppression control method of the flexible-joint series robot is studied.Firstly,the dynamic model of the flexible-joint manipulator is established,and then the vibration evaluation function of the manipulator is established based on the residual energy method.Then,the off-line optimal trajectory is searched by using particle swarm optimization(PSO).Finally,the online vibration suppression path planning method based on BP neural network is established,whose training samples are supplied by the offline optimal trajectory searching method based on PSO.The effectiveness of the algorithm is verified by Matlab platform simulation.This method realizes the effective vibration suppression of the flexible-joint manipulator under the open-loop control through the fast path planning based on BP neural network,which has practical significance for robots in nuclear environment without vibration sensors.Due to the great damage of nuclear environment to personnel,the operation of nuclear environment highly depends on robot equipments.Some complex operations often need two robots to cooperate.For example,some workpieces requires one manipulator to clamp and the other manipulator to operate.Due to the process requirements,the task space of multi-manipulator cooperative operation also needs to be constrained.Aiming at the dynamic control problem of double manipulators cooperative operation with time-varying task space constraints,a dynamic controller of double manipulators cooperative operation with known model parameters is constructed by using barrier Liapunov method,and the dynamic controller of double manipulator cooperative operation with unknown model is constructed by using radial basis function(RBF)neural network.Finally,the effectiveness of the dynamic controller is verified by simulation.In this method,a dynamic controller for dual manipulators is proposed to realize the cooperative operation of dual manipulators with unknown dynamic parameters and timevarying task space constraints.Furthermore,the mechanical systems of the 7-DOF manipulator and 9-DOF robot are designed in detail,and a robot design scheme with high protection and easy maintenance is designed.The key technologies of robot’s adaptability to nuclear environment are studied,including the radiation resistance of polymer materials and the radiation resistance reinforcement technology of robot.On this basis,the type-selection and prototype manufacturing are carried out,and the performance and function tests of the prototype are carried out to verify the rationality of the design.