Backstepping Sliding Mode Course Control for the Hovercraft With Yaw Rate Constraint and System Uncertainty

The course control problem of hovercraft with yaw rate constraint is studied under the system uncertainty caused by model parameter uncertainties and external disturbances. Firstly, a sliding mode observer is proposed to estimate the system uncertainty, which effectively compensates the influence of uncertainty in the process of course control. Secondly, the direct method and indirect method are used to constrain the yaw rate while designing the controller with the backstepping sliding mode. The auxiliary dynamic system is used to adjust the control input in the direct method, while the auxiliary dynamic system is used to constrain the virtual yaw rate, at the same time, the barrier Lyapunov function is used to limit the yaw rate error in the indirect method. Finally, simulation results verify the effectiveness of the method proposed in the terms of uncertainty estimation and yaw rate constraint of hovercraft. It also shows that the indirect method is better than the direct method to strictly constrain the yaw rate.