H∞-optimal sampled-data control: computation and design

H_∞-optimal control of sampled-data systems is considered. The H_∞ analysis or synthesis problem requires iteration on the achievable performance level γ. For each iteration, the sampled-data problem is reduced to an equivalent discrete-time problem. In this paper, a new set of formulas is obtained for the equivalent discrete-time system; in each iteration, the formulas depend on computing only one matrix exponential function. The formulas are applied to a design example and the results show clear advantage of the direct sampled-data design approach over the conventional approach of analog design and digital implementation.