Observer-based adaptive output feedback tracking control of dynamically positioned surface vessels

In this work, we propose an observer-based adaptive output feedback tracking controller for dynamically positioned surface vessels. Specifically, to remove the velocity measurement dependency of the control formulation a nonlinear, model-free observer formulation have been proposed. The proposed observer does not make use of the system dynamics and together with the proposed controller structure ensure that the tracking error signal and the velocity estimation error asymptotically converges to zero. Stability of the closed-loop system is ensured by Lyapunov-based arguments. Simulation studies are also presented to illustrate the effectiveness of the proposed method.