Output-Feedback Stabilization for Nonlinear Systems with Unmeasured States Dependent Growth

In this paper, the globally asymptotical output-feedback stabilization problem is investigated for a class of nonlinear systems with unmeasured states dependent growth and stable zero-dynamics. Because it is difficult to directly carry out the output-feedback control design for the system under consideration, a series of novel linear transformations are first defined to successfully separate the zero-dynamics from the original system, and the new system is thus derived which is convenient for the output-feedback design. Then, a simple design procedure is given for the output-feedback control of the transformed new system. This procedure is developed by extending the methods by H.L. Choi and J.T. Lim (2005), rather than the backstepping approach by P. Krishnamurthy et al. (2001). Besides, the globally asymptotical stability of the closed-loop system can be ensured by the positive definiteness of the derived matrix.