LAUSR

Abstract This work investigates the problem of designing H∞ and H2 output-feedback controllers for discrete-time linear systems with time-invariant uncertainties. The proposed control law incorporates samples of the system output measurements over several instants of time, producing a controller with memory that can provide an improved performance to the closed-loop system. Sufficient parameter-dependent linear matrix inequality conditions are given for the computation of the gains associated with the incorporated measurements. A bound to the H∞ or the H2 norms of the closed-loop system is assured by means of a parameter-dependent Lyapunov matrix. Numerical examples illustrate the advantages of the proposed approach when compared to other methods from the literature, showing that better H∞ and H2 performance can be obtained by increasing the amount of information in the control law.