convertToSugeno

Transform Mamdani fuzzy inference system into Sugeno fuzzy inference system

Syntax

sugenoFIS = convertToSugeno(mamdaniFIS)

Description

example

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

Examples

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Load a Mamdani fuzzy inference system.

mam_fismat = readfis('mam22.fis');

Convert this system to a Sugeno fuzzy inference system.

sug_fismat = convertToSugeno(mam_fismat);

Plot the output surfaces for both fuzzy systems.

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

The output surfaces for both systems are similar.

Input Arguments

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Mamdani fuzzy inference system, specified as a mamfis object. Construct mamdaniFIS at the command line or using Fuzzy Logic Designer. For more information, see Build Fuzzy Systems at the Command Line and Build Fuzzy Systems Using Fuzzy Logic Designer.

Output Arguments

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Sugeno fuzzy inference system, returned as a sugfis 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.

  • If sugFIS has a single output variable and you have appropriate measured input/output training data, you can tune the membership function parameters of sugFIS using anfis.

Introduced in R2018b