ROBUST SEMIGLOBAL OUTPUT TRACKING FOR NONLINEAR SINGULARLY PERTURBED SYSTEMS

In this work, a robust controller design methodology for a broad class of singularly perturbed nonlinear systems with time-varying uncertain ties is developed. When the fast subsystem is stabilizable and the slo w subsystem is input/output linearizable with input-to-state stable (I SS) inverse dynamics, the developed state feedback controller guarante es boundedness of the trajectories of the closed-loop system and robus t output tracking with arbitrary degree of asymptotic attenuation of t he effect of uncertainty on the output, for initial conditions and unc ertainties in an arbitrarily large compact set, so long as the singula r perturbation parameter is sufficiently small. The controller is a co ntinuous function of the state of the system and its construction requ ires the knowledge of bounding functions on the size of uncertainty. T he developed method is applied to a non-isothermal continuous stirred tank reactor with fast jacket dynamics.