Restricted Global Robust Output Regulation for Output Feedback Systems with Nonlinear Exosystems

In this paper, we study the global robust output regulation problem for output feedback systems with nonlinear exosystems. Under a set of standard assumptions, it is shown that, for any given exogenous signals generated by the exosystem contained in some compact set and any set of unknown constant parameter, there exists an output feedback controller such that the solution of the closed-loop system, starting from any initial state of the closed-loop system, exists and is bounded for all t > 0, and the tracking error e approaches zero asymptotically. Such problem is called restricted global robust output regulation problem as opposed to the global robust output regulation problem defined previously.