Global practical tracking for a class of uncertain nonlinear systems via sampled-data control

This paper investigates the problem of global practical tracking via sampled-data output feedback for a class of uncertain nonlinear systems whose output functions are not precisely known. To solve the problem, we first construct a new sampled-data compensator and then use the backstepping and output feedback domination approach to design a linear sampled-data controller. An explicit formula for the sampling period is computed to regulate the tracking error under the proposed controller with appropriate gains. A practical example is given to illustrate the effectiveness of the proposed scheme.