Two-degree-of-freedom controller design for an ill-conditioned distillation process using ľ-synthesis
Petter Lundström, Sigurd Skogestad, and John C. Doyle

IEEE Transactions on Control Systems Technology
7 (1), 1999, pp 12-21

Abstract

The structured singular value framework is applied to a distillation benchmark problem formulated for the 1991 IEEE Conference on decision and control (CDC). A two degree of freedom controller, which satisfies all control objectives of the CDC problem, is designed using ľ-synthesis. The design methodology is presented and special attention is paid to the approximation of given control objectives into frequency domain weights