Robust position stabilization of underactuated hovercrafts with modeling parameter uncertainties

In this work, we investigate the position stabilization problem for the underactuated hovercraft with modeling parameter uncertainties. The second-order hovercraft model is converted into the first-order one by two coordinate transformations. Based on the converted form, two control schemes are proposed to steer the position and velocity variables to zero. The first control algorithm takes a polynomial form of states, and is able to achieve local asymptotic stability of the closed-loop system via center manifold approach. To achieve global stability of the closed-loop system, the back-stepping and Lyapunov redesign techniques are combined to derive the second control scheme ensuring global asymptotic position stabilization. Both control laws are highly robust against the model parameters. Simulation results verify the effectiveness of the proposed control laws.