Backstepping control with energy reduction for an over-actuated marine platform

We present the design of a backstepping controller for a triangular over-actuated marine platform, controlled by three rotating jets. Our goal is the stabilization of the position and the orientation of the platform, under realistic environmental disturbances, such as wind forces, wave forces and hydrodynamic forces. Actuator thrust and angle dynamics, as well as settling delays, in the rotation of the jets and in the response of the desired thrust, are included in the algorithm, despite the presence of an allocation scheme. Thrust and angle velocity, limitations are also taken into account. A Thrust Upper Limit (TUL) manipulation heuristic is introduced in order to reduce the thrust requirements and the energy consumed. The performance of the developed backstepping controller is compared to the case with and without the TUL. Simulation results show that the use of the heuristic reduces energy consumption.