Adaptive event-triggered global asymptotic full-state stabilization of under-actuated surface vessels with unknown model parameters

Abstract

This paper studies an adaptive event-triggered controller (ETC) for global asymptotic full-state stabilization of under-actuated surface vessels (USVs) with unknown model parameters. Applying an inner–outer loop structure, desired linear and angular velocities regarded as control inputs of the outer loop subsystem are designed free of any model parameters, such that the outer loop subsystem is globally asymptotically stabilized. The generated desired velocities are assigned as the reference signals for the inner loop subsystem, thereby the actual adaptive ETC is designed to track the reference velocities and to compensate for the effect of the unknown model parameters. The proposed scheme guarantees global asymptotic stability of the closed-loop system proved by the Lyapunov-based analysis. The switching threshold event-triggering mechanism (SWT-ETM) is introduced to alleviate the system’s burden requiring less resources for communication and actuator execution. Simulation results show the effectiveness of the proposed method.