Dynamic Event-Triggered 3-D Tracking Control of Underactuated AUVs Based on Conditional Disturbance Negation

This paper presents a dynamic event-triggered 3-D trajectory tracking control scheme for underactuated autonomous underwater vehicles (AUVs) with unknown dynamics and time-varying disturbances based on conditional disturbance negation method. A nonlinear disturbance observer is constructed to estimate the combined effects of these unknown dynamics and disturbances. Compared with the existing disturbance observer-based methods, the proposed control scheme not only estimates the disturbance, but also evaluates the estimated disturbance to gain insights into the dynamic characteristics of the AUVs for selective compensation measures. A dynamic event-triggered protocol is designed in controller-actuator. Building on the observer and dynamic event-triggered protocol, a 3-D trajectory tracking control law is developed. The theoretical analysis shows that the tracking error of the AUVs converges to a neighborhood around zero. Furthermore, all signals within the closed-loop system remain bounded. Simulation results, including comparisons, validate the effectiveness and advantages of the proposed control scheme.