Observer based output feedback tracking control of dynamically positioned surface vessels

This work concentrates on tracking control of dynamically positioned surface vessels where only position and orientation measurements are available. Specifically, in order to remove the velocity measurement dependency of the control formulation, we designed a nonlinear, model-free observer which enables the observer-controller couple to achieve asymptotic tracking. 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.