A First Course in FUZZY and NEURAL CONTROL

122 CHAPTER 3. FUZZY LOGIC FOR CONTROL

0

y0.5

(^2468101214) y
z 0 (1.25) = 7.060 6,heightaboveα=0. 5

3.9.3 Maxcriterionmethod ....................

This method chooses an arbitrary value from the set of values in the domain on
which the fuzzy set assumes its maximum. The output set obtained in Example
3.6 produces a value 6 ≤z 0 (1.25)≤ 9.

0

y0.5

(^246) y 8 10 12 14
z 0 (1.25)∈[6,9]
A fuzzy set could be considered as a ìpossibility distributionî of the variable
z. From common sense, we could takez 0 to be a value at which the degree of
possibility is the highest. This is the max-criterion defuzzification method.

3.9.4 Firstofmaximamethod...................

First of maxima takes the smallest value in the domain on which the fuzzy set
assumes its maximum. The output set obtained in Example 3.6 produces the
valuez 0 (1.25) = 6.