L. Marconi et A. Isidori, Mixed internal model-based and feedforward control for robust tracking in nonlinear systems, AUTOMATICA, 36(7), 2000, pp. 993-1000
The purpose of this paper is to compare different features of two approache
s to the problem of tracking-prescribed trajectories in a nonlinear system,
and to propose a possible merger of these approaches in what is called her
e the problem of "Asymptotically Robust Perfect Tracking". The latter is th
e problem of designing a feedforward/error-feedback control law achieving p
erfect tracking in case the initial conditions of the system/exosystem are
known and compatible with perfect tracking, and asymptotic tracking in all
other cases. (C) 2000 Elsevier Science Ltd. All rights reserved.