This paper addresses the problem of tracking constant references for linear systems subject to actuator saturation considering an state-space framework. The constant reference tracking and the constant disturbance rejection are taken into account by the introduction of an integral action in a unitary output feedback scheme. Based on this structure, conditions to design simultaneously a stabilizing feedback gain and an anti-windup gain are presented in the form of matrix inequalities. These conditions ensure that the trajectories of the closed-loop system are bounded in an invariant ellipsoidal set, provided that the initial conditions are taken in this set and the references and the disturbances belong to a certain admissible set. LMI-based optimization problems are then proposed to compute the gains aiming at enlarging the set of admissible references, disturbances or initial conditions.
reference tracking; actuator saturation; anti-windup; LMIs
