Research On Trajectory Planning And Force Control Method For Underwater Master-slave Manipulator

At present,the majority of nuclear accidents occur in the extreme environment of underwater radiation such as steam generators of the primary loop,spent fuel pool and reactor coolant port.It is an internationally recognized technical problem that it is very difficult and dangerous to carry out the emergency maintenance work of the leakage accident of a nuclear power station.In this paper,the master-slave underwater manipulator is mainly used for the detection and emergency repair work for steam generators of the primary loop,spent fuel pool,reactor coolant port and other locations of nuclear power plant to reduce the risk of staff injuries.The master-slave underwater manipulator was studied and the joint structure of high-precision manipulator with integrated motor of dual encoder and reducer was designed.The manipulator adopts the modular design method.The joint installation and removal problem and rapid fault repairing problem are solved.The D-H method is used to solve the positive and inverse kinematics equations of manipulator.It is verified that the kinematic solution is correct by building the MATLAB/Simulink model.The space mapping relationship between master and slave manipulators is studied.The working spaces of master and slave manipulators are simulated by MATLAB Robot toolbox.Cartesian space path planning is carried out for the developed manipulator.The traditional method of linear and circular interpolation combined with Bessel equation is used to optimize the manipulator trajectory to solve the problem of trajectory transition.It makes the trajectory of the manipulator smoother.In order to make the operator complete the work task more efficiently and accurately,the position/force hybrid control is studied based on the force telepresence technology.The operator controls the master manipulator which transmits the movement information to the slave manipulator,and the slave manipulator feeds the force situation back to the master manipulator.Not only the sealing but also the water resistance problem need to be considered for the underwater manipulator.Therefore,the hydrodynamic model of slave manipulator is established.The model is simulated by Monte Carlo method.The effect of water resistance onthe manipulator was ensured.The master-slave position/force hybrid control method is studied for this model,and the position/force hybrid controller is designed.In this paper,the master-slave hybrid control of manipulator is simulated.In this paper,the master-slave hybrid control of manipulator is simulated and compared.The force feedback error is obtained by comparing the actual value with the expected value.The range of error is(-5%,15%).The method allows the operator to feel the force variation in the process of work.The experimental research on the master-slave heterogeneous manipulator was carried out,and the experimental platform was set up.The pressure experiment,load experiment and precision experiment were carried out.The rationality of the manipulator design was verified.The master-slave trajectory mapping experiment is carried out,so that the slave manipulator can track the path of the master manipulator as required.The accuracy of the master-slave heterogeneous manipulator trajectory planning is verified.Based on the force telepresence technology,the position/force hybrid control experiment of the master-slave manipulator is completed,which proves the proposed position/force hybrid control method is feasible.