Dynamic minimum time trajectory planning and tracking of 6-DOF underwater manipulator

The underwater stationary intervention object is moving relatively to underwater manipulator base when underwater vehicle is hovering. To realize the relative dynamic object operation, cubic B-spline is used in manipulator trajectory planning. This paper provides maximum interval of two adjacent control points to adjust the control points near dynamic object to generate smooth trajectory in real time. The approximate minimum time trajectory is achieved by setting maximum adjacent control points´ interval. Gradient Projection Method (GPM) with new function scalar is introduced to optimize the trajectory in joint space when manipulator is tracking the dynamic trajectory in Cartesian space. Trajectory planning and tracking simulation for a fixed base 6-DOF underwater manipulator is presented in the last.