Robust Stabilization of Uncertain Systems with Measurement Sensitivity Using Output Feedback

We prove that global robust stabilization is possible by output feedback for a class of nonlinear systems with measurement sensitivity characterized by an unknown time-varying parameter. The nonlinear systems under consideration are assumed to satisfy a linear growth condition with a polynomial output-dependent rate, and thus cover a larger class of uncertain systems than the previous ones studied in [15], [2]. To deal with effectively the polynomial nonlinearity and the measurement sensitivity, we propose an estimator with a high-gain that needs to be updated dynamically. Then, an estimator-based controller is constructed step-by-step, achieving global state regulation of the resulting closed-loop system.