Prod. Sigmoidal MF

Product of two sigmoid membership functions in Simulink software

Description

The Prod. Sigmoidal MF block implements a membership function based on the product of two sigmoidal curves. The two sigmoidal curves are given by

$f_{k} (x) = \frac{1}{1 + \exp (- a_{k} (x - c_{k}))}$

where k=1,2 The parameters a₁ and a₂ control the slopes of the left and right curves. The parameters c₁ and c₂ control the points of inflection for the left and right curves. Parameters a₁ and a₂ should be positive and negative respectively.