Dynamic Positioning Control for Unmanned Marine Vehicles With Thruster Faults and Time Delay: A Lyapunov Matrix-Based Method

This article investigates the problem of dynamic positioning (DP) control for unmanned marine vehicle (UMV) subject to thruster faults and time delay. Time delay is a negative factor for DP of the UMV. Therefore, proposing a better time delay compensation method is necessary. This article first introduces a novel Lyapunov matrix-based complete-type Lyapunov-Krasovskii functional (LKF), in which more comprehensive delay information is considered. An effective time delay compensation strategy in the framework of complete-type LKF is then designed, which leads to less conservativeness. The upper bounds of time-varying stuck fault and disturbance are estimated by the adaptive mechanism. Based on it, an adaptive fault-tolerant controller is proposed to compensate the effect of thruster faults, time delay, and disturbance. Furthermore, it is shown that the state errors of UMV converge asymptotically to zero. Finally, the simulation comparison results to validate the effectiveness of the proposed Lyapunov matrix-based method.