Robust Adaptive Finite-time Fault-tolerant Control for Dynamic Positioning of Vessels

In this paper, a novel robust adaptive finite-time fault-tolerant control (FTC) scheme is presented for the dynamic positioning (DP) of vessels under thruster faults with unknown model parameters and environmental disturbances. The thruster effectiveness factor to express the loss-of-effectiveness fault state is transformed into a new unknown parameter, which is obtained by the adaptive law. Furthermore, based on the finite-time control technique, neural networks (NNs) technique and the sliding mode differentiator, a novel robust adaptive finite-time FTC strategy is developed for DP of vessels by resorting the backstepping design technique. It is theoretically proved that the proposed FTC scheme can force the vessel arrive at the desired position and heading in a finite time, while guaranteeing the boundedness of all signals in the closed-loop of DP control system. Simulation study results are provided to demonstrate the effectiveness of the proposed FTC scheme.