Research On Trajectory Planning And Tracking Of Manipulator In Decommissioning Of Radioactive Container

The application of manipulator in the task of nuclear decommissioning is paid more attention than ever.Under the characteristics of inte nsive work,complicated work environment,serious radiation detriment and complex dismantling process,the manipulator trajectory planning problem in task space has important influence in state-of-the-art and smooth operation of manipulator for decommissioning task of the radioactive container.In this research,ultimate goal is decommissioning and dismantling of radioactive vessel and YASKAWA MH6S(6 degree of freedom robot)is used for experiments.The key position and pose of the cutting task is described through sampling in task space.The moving trajectory of manipulator which meets the requirement of cutting technique is planned with the help of pose planning an d position planning algorithms and these are appropriate for MH6 S.These methods ensure th at the manipulator can obtain smooth,stable and accurate pose track time function?_e(t),establishing the mapping relationship between the task and joint space through screw theory.It helped to make trajectory time function ?_e(t)with the energy optimal condition in the task space to get it mapped into joint space.Further studies include the trajectory tracking control method with the given reference trajectory input,which has a great significance not only to stabilize manipulator operations,but also increase reliability of the system along with a significant increase in efficiency.This paper further puts the position and pose planning of trajectory in the task space of MH6 S 6-degree-of-freedom manipulator and created mapping relation from task space to joint space.Finally,considering the trajectory time function ?_e(t)in the joint space as the given reference input of the manipulator,it verifies the trajectory tracking control algorithm.Through the non-uniform cubic B-spline interpolating algorithm,this paper illustrates a position planning method regardin g trajectories with the constraints of continuous path point in the task space;by using unit-quaternion and cubic polygon spline interpolating algorithm.This research also achieved the pose planning on the multi-pose constraints trajectories and sequenti ally realizes the manipulator 's pose planning with constraint of continuous path point in the task space.Along with that,it also utilized the quintic spline interpolating algorithm to plan the successive position and pose in the joint space.Path Plann ing is the basis of trajectory tracking of the manipulator.Taking the planned trajectory time function as the reference input of the control system,it utilized PD control algorithm with gravity compensation and established an argument that the manipulator can track and verify the reference trajectory using Lagrangian formula to build the dynamical model.Similarly,the trajectory planning with consecutive path points constraints and referenced task description is carried out by MATLAB /SIMULINK and Visual Studio,combining with screw theory to map the trajectory time function,planned in the task space and mapped into the joint space,realizing the successive planning on the trajectory smoothing in the joint space by utilizing the quintic spline interpolating.Experimental results show that proposed method in this paper is feasible for the trajectory planning of continuous path point constraint in the task space and lays a foundation for offline programming of manipulator.