Product of two sigmoid membership functions in Simulink software
The Prod. Sigmoidal MF block implements a membership function based on the product of two sigmoidal curves. The two sigmoidal curves are given by
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.