Output Feedback Constant Reference Tracking and Disturbance Rejection for Constrained Linear Systems

Set-invariance techniques are proposed to provide a solution to the problem of tracking a constant reference signal for constrained, linear, discrete-time systems in the presence of bounded additive disturbances via output feedback control. We consider the special case in which the disturbances are supposed to be constant. In this regard, Output-Feedback Controlled Invariant Polyhedra, robust with respect to the disturbances, are used to ensure that the constraints are satisfied all time. In particular, based on the evolution of the sets of possible state and disturbance values consistent with present and previous output measurements, we design a dynamic output feedback controller which is able to achieve reference tracking under state and control constraints during the transient period in spite of the disturbances. The results are illustrated by numerical examples. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.