Robust Antiwindup for One-Sided Lipschitz Systems Subject to Input Saturation and Applications

Abstract

This paper presents the robust nonlinear dynamic antiwindup compensator (AWC) design for nonlinear systems with parametric uncertainties and one-sided Lipschitz nonlinearities under actuator saturation. A decoupling architecture for a full-order AWC is proposed for the case of parametric uncertainties. AWC synthesis scheme is derived by employing the quadratic Lyapunov function, the notion of quadratic inner-boundedness, the one-sided Lipschitz condition, sector condition, and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gain minimization. An algorithm, based on the convex routines, by employing the cone complementary linearization, recursive computation, and a bilinear term resolving approach is provided for obtaining the AWC parameters. In contrast to the existing nonlinear AWC designs, our results provide a remedy to the input saturation for a widespread class of nonlinear systems and can effectively deal with the parametric uncertainties. The suggested AWC methodology is employed to compensate windup in the buck-boost converter and one-link flexible robot with revolute joint.