Output tracking problem for systems with input saturations via nonlinear integrating actions

Abstract

In this paper we synthesize nonlinear state feedback controllers for locally stabilizing linear systems with both saturating actuators and additive disturbances when the output must track a certain reference level. The objective is to bring the steady-state error due to disturbances to zero by using a saturated controller that contains a nonlinear integrating action. The objective is two-fold since we want to determine both a stabilizing controller and a region of the state space over which the stability of the resulting closed-loop system is ensured, when the controls are allowed to saturate. The controller gains and the associated domain of stability are synthesized by using either Riccati equations (ARE) or linear matrix inequalities (LMIs). Copyright © 2000 John Wiley & Sons, Ltd.