Non-fragile mixed H2/H∞ control for discrete-time system with multiplicative controller gain variations

This paper is concerned with the problem of a non-fragile mixed H₂/H_∞ controller design for linear discrete-time systems in the presence of multiplicative controller gain variations. The purpose of work is to design a dynamic output feedback controller via matrix inequalities such that the closed-loop system is asymptotically stable and has mixed H₂/H_∞ performance criterions. Further, the result can be easily extended to robust non-fragile mixed H₂/H_∞ dynamic output feedback controller design for the convex polytopic uncertain discrete system via the affine characteristic of matrix inequality. Two numerical examples are given to illustrate the design procedure and its effectiveness.