Guaranteed cost robust Hinf reliable control for a class of uncertain time-varying delay systems

The problem of guaranteed cost robust Hinf reliable control is investigated for time-varying delay uncertain systems against actuator failures. In the considered system, the time-varying delay and its derivative are bounded. Actuators are classified into two sets (One set is susceptible to failure and the other set is not susceptible to failure). All the outputs of the failure actuators are assumed to be zero. Based on Lyapunov stability theory, a sufficient condition of the existence of guaranteed cost robust Hinf reliable controller is derived and furthermore transformed to a linear matrix inequality (LMI). At the same time, the designing approach of state feedback controller is presented and the upper bound of guaranteed cost function is given. The resultant control systems not only could retain asymptotic stability and disturbance attenuation with Hinf-norm bounds but also possess the performance index of guaranteed cost irrespective of any outages within a prespecified subset of actuators.