A rough set solution to a fuzzy set problem

When designing a Takagi-Sugeno (TS) fuzzy controller, reducing the number of rules makes it easier to derive a stable Lyapunov based controller using linear matrix inequalities (LMIs). The paper describes an intuitive way of reducing a fuzzy ruleset by eliminating rules that are very similar in terms of parameters and membership functions. It is then suggested that a more formal approach to this intuitive idea may be found in rough set theory.