Reduced-order controllers for unstable multivariable linear systems that can be balanced

摘要

This paper considers the problem of H∞-stabilization of unstable multivariable linear systems. The major features of the approach are: (1) a reduced-order model is obtained using low-frequency balancing, the approximant will have the same number of unstable poles as the original system, (2) the controller design is accomplished by dynamic output feedback, and (3) sufficient conditions in the form of two algebraic Riccati equations and an upper bound explicitly characterize a H∞-controller of lower dimensions. At the end, an illustrative example is given to show the simplicity of the procedure.