Discrete-time Gain-Scheduled Output-Feedback controllers exploiting inexact scheduling parameters

This paper addresses the design problem of Gain-Scheduled Output-Feedback (GSOF) controllers for discrete-time Linear Parameter-Varying (LPV) systems. In our problem setting, the scheduling parameters are supposed to be provided with some uncertainties. The LPV systems as well as the GSOF controllers to be designed are supposed to be parametrically affine. Two design problems, i.e. H_∞-type and H₂-type problems, are addressed using parameter-independent Lyapunov functions. We give sufficient conditions for our problems in terms of parametrically affine Linear Matrix Inequalities (LMIs) with a single line search parameter. Our result recovers the conventional result when exact values of scheduling parameters are available.