Output Feedback Stabilization of Nonlinear Systems with Uncertain Integrators

Abstract: We present a control design to solve the global output feedback stabilization problem of a class of uncertain nonlinear systems. Each system in this class consists of some dynamic uncertainties, linear parametric uncertainties and, most importantly, output-dependent uncertain integrator gains or virtual coefficients. To solve the problem, an observer design is proposed, and the robust adaptive backstepping and the nonlinear small gain techniques are applied to construct an output feedback dynamic controller. The controller guarantees that all the closed-loop signals are bounded and also the output of the systems can be made arbitrarily small. If extra conditions are imposed on the systems, regulation of the systems’ states can also be achieved.