A Dual Observer Method for Global Stabilization of Nonlinear Systems with Limited and Uncertain Information

This paper considers a general setting for the stabilization of a planar nonlinear system given only the measurement of the output state. Additionally, we assume that a certain amount of uncertainties is inherent in the system under consideration, where we only need to know the bounding function of the nonlinear terms. Under this setting we consider a class of systems whose nonlinear bounding functions are polynomially bounded in the unmeasurable state, with orders both greater than and less than one. The primary novelty of this method is the utilization of a dual observer approach, estimating lower-order states and higher-order states in parallel.