Fuzzy logic
- Fuzzy logic: a computational approach centered on the idea of ‘degrees of truth’ rather than the black/white true or false approach of most systems.
- Fuzzy membership function: permit individuals to be partial members of different, overlapping sets( crossover point: the point where the grade of membership is 0.5 )
Left sigmoidal: requires two parameters, expressed fall
Sigmoidal or triangular function: requires three parameters representing about
Trapezoidal-shaped: four required parameters for moderate
Right trapezoidal function: requires two parameters, indicate an increase
- Fuzzy operators:
And: The output map is controlled by the smallest fuzzy membership value at each location.
Or: Output membership is controlled by the maximum value of input maps
Fuzzy Algebraic Product: output is always less than or equal smallest FM, FM all values are involved
Fuzzy Algebraic Sum: sum of 0.75, 0.5 = 1- (1-0.75) * (1-0.5) = 0.875, the result is always larger than the maximum