Abstract
In the design of feedback control systems, two kinds of uncertainties must be considered. One is the external disturbance, the other is the plant perturbation, which is caused by the variance of the parameters and the uncertainties of the mathematical model of the plant. The second must be considered seriously by system synthesis because the uncertainties can harm the stability of the colsed-loop system. A controller that satisfies the stability requirement under perturbation is the main aim of robust control.
In the case of centralized control systems, there are a lot of studies which are concerned with the robust control. Especially, the Structured Singular Value (SSV) method, developed by J.C. Doyle, et al., can deal with the robustness and performance simultaneously. This is why the SSV has received increasing attention. For the decentralized controll systems, S. Skogestad & M. Morari gave a sufficient condition for robust performance by using the SSV method.
In this paper, by using the SSV and the parameterization of all the decentralized stabilizers that the authors have obtained already, two kinds of perturbation models (an additive pertutbation and a multiplicative one) are considered.
