Robust adaptive terminal sliding mode control for dynamic positioning of a semi

In this paper, a robust adaptive terminal sliding mode controller is proposed for dynamic positioning of a semi-submersible offshore platform. First, a state feedback controller is designed to stabilize the nominal system. Then a robust adaptive terminal sliding mode compensator is developed to eliminate the effects of uncertain dynamics and disturbances. It is shown, using Lyapunov methods, that the tracking error is driven to zero in finite time using the proposed control. The efficacy of the control algorithm is validated using simulation studies; it is shown that recent developments in the domain of robust exact differentiation are very helpful for controller implementation