A coordinated trajectory tracking method with active utilization of drag for underwater vehicle manipulator systems

UVMSs suffer severe drag owing to the manipulator while tracking a trajectory at a considerable speed. Drag, considered a negative force by other researchers, can be utilized for UVMS trajectory tracking. To this end, a novel coordinated trajectory tracking method for UVMS is proposed to actively utilize drag, which consists of three parts: a trajectory planner is developed to plan the desired velocity of the vehicle for trajectory tracking; also, a motion planner is designed to schedule the movement of the manipulator to actively utilize drag and the generating turning torque on the vehicle, making the vehicle approach the desired angular velocity; additionally, a computed torque controller (CTC) is developed to control the linear velocity and joint positions and its stability is demonstrated. Different simulations are performed, the results show that drag can be actively utilized for trajectory tracking, and the combination of the proposed method with other actuators can improve the maneuverability and tracking performance of the system. Pool experiments are conducted to verify the effectiveness of the proposed method in tracking yaw angles.