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

In this paper we synthesize nonlinear state feedback controllers for locall y stabilizing linear systems with both saturating actuators and additive di sturbances when the output must track a certain reference level. The object ive is to bring the steady-state error due to disturbances to zero by using a saturated controller that contains a nonlinear integrating action. The o bjective is two-fold since we want to determine both a stabilizing controll er and a region of the state space over which the stability of the resultin g closed-loop system is ensured, when the controls are allowed to saturate. The controller gains and the associated domain of stability are synthesize d by using either Riccati equations (ARE) or linear matrix inequalities (LM Is). Copyright (C) 2000 John Wiley & Sons, Ltd.