SLAA235A February   2005  – August 2018 MSP430F147 , MSP430F147 , MSP430F148 , MSP430F148 , MSP430F149 , MSP430F149

 

  1.   Fuzzy Logic Motor Control With MSP430™ MCUs
    1.     Trademarks
    2. 1 Background Information
      1. 1.1 Fuzzification
      2. 1.2 Fuzzy Inference
      3. 1.3 Centroid Calculation Defuzzification Method
    3. 2 Hardware Description
    4. 3 Software Description
    5. 4 References
  2.   Revision History

1.2 Fuzzy Inference

Zadeh MAX-MIN relations are used, because experience proves that they give precise results. The process consists of:

  1. Clear the output vector Y[ ].
  2. Take the first member of the vector X1[ ].
  3. Compare it to every member of the vector X2[ ]. The smaller value is recorded on every comparison.
  4. The maximum value is found among the members obtained in step 3.
  5. This maximum value is then added to the output vector member which is defined by the inference rules.
  6. The next member of the vector X1[ ] is taken and the process from 3 to 6 is repeated.

Table 1 lists the inference rules.

Table 1. Fuzzy Inference Rule Table

dError, X2[ ]
NM NS ZE PS PM
Error, X1[ ] NM PM PM PM PS ZE
NS PM PM PS ZE NS
ZE PM PS ZE NS NM
PS PS ZE NS NM NM
PM ZE NS NM NM NM

In the given example, the output vector Y[ ] = [0h, 30h, 3D0h, 0h, 0h]