Robust Adpative Formation Control Strategy for Underactuated Unmanned Surface Vehicles with Unmeasurable Velocity and Actuator Saturation

A cooperative leader-formation control issues for underactuated unmanned surface vehicles (USVs) in the presence of unmeasurable velocity. All USVs are subject to unknown external time-varying disturbance, the model uncertainties, and actuator saturation. Initially, the follower USV form a formation by acquiring the leader USV's position information. Lumped interferes consisting of external time-varying interferes and the model uncertainties and velocities vector are evaluated by a third order finite-time convergent extended state observer (ESO). Meanwhile, to ameliorate the affect of actuator saturation, a finite-time auxiliary dynamic system (ADS) is introduced. First order filter is drew into the controller for decreasing the number of derivation. Closed loop system is proven to be stable in limited-time via Lyapunov stability theory. Finally, numerical simulations demonstrate the rationality and feasibility of the design of the control.