IEEE Transactions on Automatic Control, Vol.50, No.1, 111-117, 2005
Output feedback tracking: A separation principle approach
We study the practical and asymptotic tracking problem for nonlinear systems when only the output of the plant and the reference signal are available for feedback. We provide sufficient conditions and a control topology yielding practical tracking. In the special case when the reference signal is generated by an exosystem and there exists an internal model satisfying suitable observability properties. tracking becomes asymptotic.