Dynamic event-triggered composite anti-disturbance fault-tolerant tracking control for ships with disturbances and actuator faults

This paper investigates the dynamic event-triggered composite anti-disturbance and fault-tolerant tracking problem of ships with external ocean disturbances and actuator fault effects. The dynamic event-triggered composite anti-disturbance and fault-disturbance tracking is achieved by combining the disturbance observer and the fault observer with the dynamic event-triggering and the vectorial backstepping control method. The nonlinear disturbance observer is constructed to obtain the online external disturbance estimations in the ocean time-varying environment and thus overcome the unexpected disturbances. The actuator fault observer is exploited to achieve the online fault estimations of actuator faults. The dynamic event-triggered mechanism reduces execution frequencies of control signals to mitigate the tear and wear of ship actuators. The dynamic event-triggered composite disturbance compensation fault-tolerant control ensures the globally uniformly ultimately stability of tracking control system and enables the ship to track the expected trajectory with the small errors. Simulations and comparisons with static event-triggered control on a full-scaled ship validate the dynamic event-triggered control.