State-space solution to the periodic multirate H/sub ∞/ control problem: a lifting approach

Abstract

A state-space solution to the H/sub /spl infin// control problem for periodic multirate systems is presented. The solution is based on the lifting method, where an equivalent time invariant system description is derived for the original periodic multirate problem. The H/sub /spl infin//-optimal controller for the multirate system is expressed in terms of two algebraic Riccati equations. The so-called causality constraints are represented by a set of positive definiteness conditions and coupling criteria.