Abstract
In this study, a new delay-dependent robust H∞ controller having actuator saturation method is developed to attenuate the disturbance signals acting on system have bounded energy. Based on the selection of Lyapunov-Krasovskii functional, first a Bounded Real Lemma (BRL) is obtained in terms of linear matrix inequalities (LMIs) such that the nominal, time-delay system is guaranteed to be globally asymptotically stable with minimum allowable disturbance attenuation level. Extending BRL, sufficient delay-dependent criteria are developed for a stabilizing H∞ controller synthesis involving a matrix inequalitiy. A new H∞ controller is designed for a system having actuator saturation, norm-bounded uncertainties and actuator delay by the use of extended BRL and H∞ stabilisation criteria. This sufficient condition for designing such controller is given by delay- dependent bilinear matrix inequalities and a cone complementary algorithm is also utilized to solve the non-convex optimization problem. To show the effectiveness of the approach, performance of the proposed controller is examined in disturbance attenuation problem of seismic excitations, in a structural system having norm bounded uncertainties. The time history and frequency responses of structural system under seismic excitations show that the design controller has high damping performance and guarentees stability at maximum actuator delay and parameter uncertainty bounds under actuator saturation constraints.