SIMULTANEOUS H-INFINITY CONTROL OF A FINITE COLLECTION OF LINEAR PLANTS WITH A SINGLE NONLINEAR DIGITAL CONTROLLER

This paper considers the problem of simultaneous H-infinity control of a finite collection of linear time-invariant systems via a nonlinear digital output feedback controller. The main result is given in terms of the existence of suitable solutions to Riccati algebraic equations and a dynamic programming equation. Our main result shows that if the simultaneous H-infinity control problem for k linear time-invariant pl ants of orders n(1), n(2), ..., n(k) can be solved, then this problem can be solved via a nonlinear time-invariant controller of order n<(De lta)double under bar> n(1) + n(2) + ... + n(k). (C) 1998 Elsevier Scie nce B.V. All rights reserved.