Event-triggered cooperative path following control of multiple underactuated unmanned surface vehicles with complex unknowns and actuator saturation

Abstract

We propose an event-triggered cooperative control scheme to address the path following problem of multiple underactuated unmanned surface vehicles (USVs) under complex unknowns and actuator saturation. The control law combines the line-of-sight navigation principle, backstepping technology, an uncertainty and disturbance estimator (UDE), an auxiliary system, a high-gain observer (HGO) and an event-triggered mechanism (ETM) to realize the path following control of individual USVs. A path update law is established based on the synchronization scheme. Our control strategy features the following two aspects: (i) the UDE and HGO are jointly constructed to estimate complex unknowns of USV formation with actuator saturation, and (ii) an ETM is employed to reduce the update frequency of the controller. The system stability is proved using the Lyapunov method. Numerical simulations and comparison with other control strategies demonstrate the feasibility and effectiveness of the proposed strategy.