Adaptive dynamic control allocation for over-actuated dynamic positioning system based on backstepping method in case of thruster faults

Abstract The objective of the research considered in this paper is dynamic positioning of a nonlinear over-actuated marine vessel in the presence of limited information about thruster forces. First, the adaptive backstepping method is used to estimate the input matrix which will compensate partial loss of actuator effectiveness in the presence of actuator dynamics. Then, the adaptive commanded virtual forces and moment are allocated into individual thrusters by employing the control allocation algorithm to compensate total faults. The effectiveness of the proposed control scheme is demonstrated by simulations involving a redundant set of actuators, when actuators lose partially their efficiency or failed.