欠驱动船舶的光滑时变全局渐近镇定

研究了欠驱动船舶的镇定问题。首先，通过恰当的坐标变换将整个动态系统转换成级联结构的非线性系统；其次，利用backstepping使得最后要镇定的问题变成一个3阶链式无漂移系统的镇定；再次，设计了光滑时变的反馈控制律，使系统全局渐近稳定到期望的平衡点。文章的设计方法是系统的，采用的技术都是现有的一些方法，主要是Lyapunov分析、级联方法、backstepping和坐标变换。仿真结果表明了该方法的有效性。

Smooth Time-Vvarying Global Asymptotically Stabilization for Under-Actuated Vessels

In this paper, the stabilization problem of an underaetuated vessel was studied. First, through a suit- able change of coordinates, the whole dynamical system was transformed into a third order driftless cascade non- linear system. Second, with backstepping technique, the control problem of the resulting system could be re- duced to the stabilization of a third-order chained form. Third, a smooth time-varying feedback law was derived to guarantee global uniform asymptotic stabilization of the system to the desired equilibrium. This law was de- signed on a systematic way with a general existence results. The techniques employed here we＇t＇e basic, such as classical Lyapunov analysis, cascaded approach, backstepping and change of coordinates. Simulation results show ed ihat the proposed control laws were effective.