A BOUND OF CONSERVATIVENESS IN SAMPLED-DATA ROBUST STABILIZATION AND ITS DEPENDENCE ON SAMPLING PERIODS

摘要

This paper investigates conservativeness of the L-2-induced norm in a sampled-data robust stabilization problem. Namely, it is shown that possible conservativeness of the L-2-induced norm can be bounded by the difference between the best achievable performance of time-invariant continuous-time controllers and that of sampled-data controllers. Moreover, this difference is proven to approach zero as a sampling period tends to zero, which means the conservativeness above loses importance when a sampling period is small. These results are important because robust stabilization based on the L-2-induced norm is computationally inexpensive compared with robust stabilization based on the non-conservative robust stability index. One key lemma plays an essential, role in this paper and it should be interesting independently. (C) 1997 Elsevier Science B.V. [References: 22]