THE ALGORITHMS FOR STUDYING THE TRADE-OFFS BETWEEN H-INFINITY, ATTENUATION AND UNCERTAINTY TOLERANCE

Uncertainty tolerance and H-infinity attenuations are two important concerns in feedback control design. It is therefore important to develop effective methods to compute the trade-off between these two objectives. Using a quasiconvex optimization approach, this paper develops algorithms for two problems in this regard: (1) given the uncertainty size of the system, compute the minimum H-infinity norm bound of the closed loop system reachable by state feedback control; and (2) given the required maximum acceptable H-infinity norm bound of the closed loop system, compute the maximum uncertainty size which can be tolerated when state feedback control is applied. A numerical example is included to show the trade-off between uncertainty tolerance and H-infinity attenuations, and the effectiveness of the algorithms.