convertToSugeno

Convert Mamdani fuzzy inference system into Sugeno fuzzy inference system

Syntax

sugenoFIS = convertToSugeno(mamdaniFIS)

Description

sugenoFIS = convertToSugeno(mamdaniFIS) converts the Mamdani fuzzy inference system mamdaniFIS into a Sugeno fuzzy inference system sugenoFIS.

Examples

Transform Mamdani FIS into Sugeno FIS

Load a Mamdani fuzzy inference system.

mam_fis = readfis('mam22.fis');

Convert this system to a Sugeno fuzzy inference system.

sug_fis = convertToSugeno(mam_fis);

Plot the output surfaces for both fuzzy systems.

subplot(2,2,1)
gensurf(mam_fis)
title('Mamdani system (Output 1)')
subplot(2,2,2)
gensurf(sug_fis)
title('Sugeno system (Output 1)')
subplot(2,2,3)
gensurf(mam_fis,gensurfOptions('OutputIndex',2))
title('Mamdani system (Output 2)')
subplot(2,2,4)
gensurf(sug_fis,gensurfOptions('OutputIndex',2))
title('Sugeno system (Output 2)')

The output surfaces for both systems are similar.

Input Arguments

mamdaniFIS — Mamdani fuzzy inference system

mamfis object | mamfistype2 object

Mamdani fuzzy inference system, specified as a mamfis or mamfistype2 object.

mamdaniFIS must not contain rules with NOT logic in the consequent.

Output Arguments

sugenoFIS — Sugeno fuzzy inference system

sugfis object | sugfistype2 object

Sugeno fuzzy inference system, returned as one of the following:

• sugfis object when mamdaniFIS is a mamfis object

• sugfistype2 object when mamdaniFIS is a mamfistype2 object

sugenoFIS:

• Has constant output membership functions, whose values correspond to the centroids of the output membership functions in mamdaniFIS

• Uses the weighted-average defuzzification method

• Uses the product implication method

• Uses the sum aggregation method

The remaining properties of sugenoFIS, including the input membership functions and rule definitions remain unchanged from mamdaniFIS.

Tips

• If you have a functioning Mamdani fuzzy inference system, consider using convertToSugeno to convert to a more computationally efficient Sugeno structure to improve performance.

Alternative Functionality

App

You can interactively convert a Mamdani FIS into a Sugeno FIS using the Fuzzy Logic Designer app. You can then export the system to the MATLAB^® workspace.

Version History

Introduced in R2018b

R2018b: Replaces mam2sug

This function replaces mam2sug for converting a Mamdani system to a Sugeno system.