Robust non-fragile finite frequency [formula omitted] control for uncertain active suspension systems with time-delay using T-S fuzzy approach

Abstract

In this paper, the problem of non-fragile H∞ control for uncertain active suspension systems (ASSs) with time-delay is investigated via a fuzzy control approach in the finite frequency domain. Firstly, considering the variation of sprung and unsprung masses, a Takagi-Sugeno (T-S) fuzzy model is constructed to describe the nonlinear suspension dynamics based on a typical quarter-automobile ASS model. Meanwhile, the input delays and gain perturbations of the actuator are considered to approximate the real physical device situations in the control systems. Secondly, through combining Lyapunov stability theory, generalized Kalman-Yakubovich-Popov (GKYP) lemma with the further universalization of the strict S-procedure, a sufficient condition is presented to ensure that the resulted closed-loop system is asymptotically stable and satisfies the desired finite frequency H∞ performance simultaneously. Furthermore, the existing conditions of the fuzzy controller are given as a convex optimization problem in terms of a set of linear matrix inequality (LMI) constraints. Finally, numerical simulations are implemented to examine the effectiveness and performance advantages of the proposed control approach.