Delay-dependent H∞ variable structure control of uncertain singular time-delay systems:: An LMI approach

A delay-dependent H-infinity variable structure control is presented for uncertain singular time-delay systems. System with mismatched norm-bounded uncertainties and mismatched norm-bounded external disturbances are considered. In terms of linear matrix inequalities (LMIs), we give a delay-dependent sufficient condition for the existence of switching surfaces, on which sliding mode dynamics is regular, impulse free, and internally asymptotically stable and satisfies H-infinity performance. We also give an explicit formula of such linear switching surfaces. A state feedback controller is derived to guarantee system trajectories convergent to the linear switching surface.