Disturbance observer‐based event‐triggered tracking control of underactuated surface vessels with prescribed performance

This paper addresses the trajectory tracking control problem for underactuated surface vessels (USVs) subject to model uncertainties and external disturbances. A composite adaptive finite‐time event‐triggered control (ETC) scheme with prescribed performance is proposed. To relax the restrictive initial condition requirements in conventional prescribed performance control (PPC), a finite‐time prescribed performance function is introduced. This function allows flexible error boundary assignment while ensuring smooth control signals, which mitigates actuator wear, improves transient response, and avoids potential singularity issues. Furthermore, an adaptive event‐triggered mechanism is developed to reduce communication and computational loads by updating control signals only when necessary, thus achieving a balance between tracking performance and operational efficiency. By integrating the event‐triggered mechanism, PPC, and a disturbance observer (DOB) into a unified framework, the proposed approach guarantees prescribed transient and steady‐state tracking performance, provides robustness against uncertainties and disturbances, and alleviates practical resource constraints. Simulation results on an USVs model validate the effectiveness and advantages of the proposed control scheme.