A parameter-dependent Lyapunov function based approach to H<sub>∞</sub>-control of LPV discrete-time systems with delays

Abstract

In this paper we study the problem of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control of linear parameter-varying (LPV) discrete-time systems with delays. In an LPV system, the state-space matrices are a function of time-varying parameters which are assumed to be real-time measurable. We utilize a parameter-dependent Lyapunov function to establish a delay-dependent H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance condition for the LPV system with unknown but bounded delays. On the basis of the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance condition established, we develop a linear matrix inequality (LMI) based H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control strategy. We show that solving the related LMI optimization problem paves the way for designing a H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> controller for the LPV discrete-time system with delays. We also use a numerical example to demonstrate the application of the presented H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> controller design method.