Event-Triggered Disturbance Observer-Based Control for Trajectory Tracking of Ships with Actuator Saturation

This paper presents an event-triggered anti-disturbance control scheme for the trajectory tracking of ships with time-varying ocean disturbances and actuator saturation. By combining the disturbance observer with the auxiliary dynamic system, a robust disturbance observer-based control is designed with the backstepping technique and event-triggered mechanism. The disturbance observer provides the on-line time-varying disturbance estimations. The auxiliary dynamic system helps to reduce the actuator saturation effects. The event-triggered mechanism avoids the wear and tear of actuators through implementing the control signals on triggering periods. It is theoretically proven that the event-triggered anti-disturbance controller achieves the trajectory tracking and all signals in the closed-loop tracking control systems are uniformly ultimately bounded. Illustrative simulations on a 1:70 scaled model ship confirm the event-triggered anti-disturbance tracking control.