Trajectory Tracking for Underwater Swimming Manipulators using a Super Twisting Algorithm

International audienceThe underwater swimming manipulator (USM) is a snake-like, multi-articulated, underwater robot equipped with thrusters. One of the main purposes of the USM is to act like an underwater floating base manipulator. As such, it is essential to achieve good station-keeping and trajectory tracking performance for the USM using the thrusters, while using the joints to attain a desired position and orientation of the head and tail of the USM. In this paper, we propose a sliding mode control (SMC) law, in particular the super-twisting algorithm with adaptive gains, for trajectory tracking of the USMs center of mass. A higher-order sliding mode observer is proposed for state estimation. Furthermore, we show ultimate boundedness of the tracking errors and perform a simulation study to verify the applicability of the proposed control law and show that it has better tracking performance than a linear PD-controller