Robust controller design for a heating system

Abstract

A new robust linear controller design procedure is applied to the design of a controller for the heating system of a pilot plant distillation column. The heating system exhibits nonlinear dynamics. For design purposes, it is represented by seven linear time-invariant models obtained at different operating points. The robust control design procedure combines the loop-shaping design procedure (LSDP) and the controller design method by frequency response approximation (FRA). A scaling procedure by which the condition number of the plant model is reduced is used to facilitate the design. The controller for the scaled system is then rescaled to control the original system. The order of the controller is reduced using again the FRA procedure. The results of the simulation of the nonlinear plant model show that the design was successful. Copyright © 1999 John Wiley & Sons, Ltd.