Dynamic output feedback stabilization for systems with sector-bounded nonlinearities and saturating actuators

In the present work a systematic methodology for computing dynamic output stabilizing feedback control laws for nonlinear systems subject to saturating inputs is presented. In particular, the class of Lur’e type nonlinear systems is considered. Based on absolute stability tools and a modified sector condition to take into account input saturation effects, an LMI framework is proposed to design the controller. Asymptotic as well as input-to-state and input-to-output (in a L2 sense) stabilizations are addressed both in regional (local) and global contexts. The controller structure is composed by a linear part, an anti-windup loop and a term associated to the output of the dynamic nonlinearity. Convex optimization problems are proposed to the controller synthesis considering different optimization criteria. A numerical example illustrates the potentialities of the methodology.