H-INFINITY AND H-2 DESIGN TECHNIQUES FOR A CLASS OF PREFILTERS

This paper presents H-infinity and H-2 techniques for the design of a certain class of prefilters. In order to avoid high order prefilters w e use a particular structure in which both prefilter and feedback cont roller share the same dynamics. The suboptimal H-infinity design probl em is shown to be equivalent to an linear matrix inequality (LMI) cons traint, and the solution of the H-2 optimal design may be obtained by a simple formula. The H-2 technique developed will be illustrated on a helicopter example and compared with classical techniques.