Input/output delay approach to robust sampled-data H_∞ control

Sampled-data output-feedback H∞ control of linear systems is considered. The only restriction on the sampling and hold is that the distances between the sequel sampling times and holding times are not greater than given bounds. A new approach, which was recently introduced to sampled-data state-feedback stabilization, is developed to the H∞ control. The system is modelled as a continuous-time one, where the control input and the measurement output have piecewise-continuous delays. Sufficient linear matrix inequalities (LMIs) conditions for H∞ control of such systems are derived via Lyapunov-Krasovskii functionals and descriptor approach to time-delay systems. For the first time the new approach allows to develop different robust control methods for the case of sampled-data H∞ control.