A catalog of LMI conditions for gain-scheduled output-feedback H∞-control

A number of Linear Matrix Inequality (LMI) conditions for the design of gain-scheduled quadratic H
_∞
output-feedback controllers can be found in the literature under a variety of assumptions on both the system as well as the controller structure. The first contribution of the present paper is to provide a catalog of such conditions, including some new conditions, which cover most practical applications. In each setup, LMI conditions allowing implicit and explicit computation of the controller matrices are provided. As a second contribution, we illustrate how to use these conditions and compare their performance using a numerical example which allows us to exercise the controller design procedure in the various scenarios covered.