Abstract
There have been a number of interesting papers on H∞ type control problems of sampled-data systems.
In order to desgin a digital controller to minimize the L2/l2(or l2/L2) induced norm of a closed-loop system, Chen and Francis gave some farmulas for the norms of SP and PH; P is a linear continuoustime system, S is an ideal sampler, and H is a zero-order hold.
Hara and Kabamba investigated the H∞ type control problems of sampled-data systems in the state spase representations and they poposed the discrete-time systems, the H∞ control problems of which have the same solusions as the original problems do. These discrete-time systems are here called to be equivalent to sampled-data systems.
This paper shows that the equivalent discrete-time systems can be derived very simply by characterizing the class of minimum energy disturbances.
