On some properties of fuzzy systems
Constantin Voloşencu · International Conference on Signal Processing · 2009
The paper presents a short review of some main properties of fuzzy systems, useful in control and other applications. Fuzzy rule bases and fuzzy systems may be seen as applications between fuzzy or real sets, with algebraic properties as: commutative law, neutral element and symmetric elements. Fuzzy systems, developed with different rule bases, fuzzy values, membership functions, fuzzyfication and defuzzification methods may be characterised with SISO and MISO transfer characteristics. A spatial sector property, useful in the stability analysis with Lyapunov techniques, may be emphasised, on these characteristics. Also, the fuzzy systems have a variable gain with its inputs. The transfer characteristics and system linearization are usefull in the design of fuzzy PID controllers. Based on the transient characteristics we are showing that the control systems based on fuzzy PI controllers assure better quality criteria then the control systems based on linear PI controllers and they are more robust.