Disturbance-observer-based path following predictive controller for underactuated surface vessels

The path-following control problem is considered for a 3 degree-of-freedom underactuated surface vessel with disturbances. The Serret-Frenet coordinate and nonlinear state transformations are used to transform the system into a SISO nonlinear chained system. By using the disturbance observer to compensate the influence of external dynamic disturbance, a composite generalized predictive anti-disturbance controller, which integrate the nonlinear disturbance observer with the feedback loop, is proposed. The controller guarantees that the system state trajectories can asymptotically track the given reference trajectories. The numerical simulations demonstrate the validity of the antidisturbance control strategy.