Path following and Stabilization of Underactuated Surface Vessels Based on Adaptive Hierarchical Sliding Mode

Path following of underactuated surface vessels is important practice in ship motion control field. Some of current studies have restrictions on forms of desired trajectory of which straight line or sinusoid curve was excluded. In this paper, adaptive robust controllers for path following of underactuated surface vessels are proposed based on hierarchical sliding mode method which suits various forms of curve. Adaptive technique is employed to deal with uncertain parameters. The proposed control strategy is robust to uncertain parameters and time-varying disturbances. Stabilization is presented as a special case. The numerical simulations are conducted to illustrate the effectiveness of the proposed methodology. Lyapunov stability theorem guarantees the stability of the closed-loop system.