Linguistic decoupling control of fuzzy multivariable processes

Abstract ‘Precise’ decoupling control techniques are likely to suffer from a serious lack of robustness since they are often too sensitive to system model uncertainties. Approximate decoupling might be one way to solve this problem. Based on fuzzy sets and system theory, the so-called ‘linguistic decoupling’ problem is considered in this paper and the design of a linguistic decoupling controller via cascade compensation is discussed, accompanied by a numerical example. The basic idea in linguistic decoupling is to decouple the system at the linguistic level rather than in a precise manner, as is usually the case.