Fuzzy Approach

CS 331/531 Dr M M Awais 2

RBS

Crisp Vs Fuzzy

young

25

age

Mem

bers

hip

valu

e

1

0

Crisp boundary

old

CS 331/531 Dr M M Awais 3

RBS

Crisp Vs Fuzzy

25

age

Mem

bers

hip

valu

e

1

0

Fuzzy boundary

old

30

young

CS 331/531 Dr M M Awais 4

RBS

Crisp Vs Fuzzy

25

age

Mem

bers

hip

valu

e

1

0

old

30

young MV of young is 1 MV of old is 0

Fuzzy Young

CS 331/531 Dr M M Awais 5

RBS

Crisp Vs Fuzzy

25

age

Mem

bers

hip

valu

e

1

0

old

30

young

Some what youngMV varies from 0.5 to 1

0.5

CS 331/531 Dr M M Awais 6

RBS

Crisp Vs Fuzzy

25

age

Mem

bers

hip

valu

e

1

0

Nearly oldMV varies from 0.5 to 0

old

30

young

Some what young

0.5

CS 331/531 Dr M M Awais 7

RBS

Fuzzy Rule Base System Fuzzify each antecedent Find the fuzzy value for the

conclusion Defuzzify this value

CS 331/531 Dr M M Awais 8

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Fuzzify the conditions

CS 331/531 Dr M M Awais 9

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

Fuzzify the conditions

CS 331/531 Dr M M Awais 10

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

Fuzzify the conclusion

CS 331/531 Dr M M Awais 11

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

Find the membership for Temp 20

CS 331/531 Dr M M Awais 12

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

20

0.3

Find the membership for humidity 20%

CS 331/531 Dr M M Awais 13

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

20

0.3

Transfer the min value as and operator exists between conditions

Transfer the values to find the membership value of Thermo

CS 331/531 Dr M M Awais 14

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

20

0.3

Transfer the min value as and operator exists between conditions

Min(0.3,0.6)

Transfer the values to find the membership value of Thermo

CS 331/531 Dr M M Awais 15

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

20

0.3 0.3

Transfer the values to find the membership value of Thermo

CS 331/531 Dr M M Awais 16

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

20

0.3 0.3

25

Defuzzify the membership value of Thermo

CS 331/531 Dr M M Awais 17

RBS

temp

Mem

bers

hip

valu

e

IF TEMP. 20C and HUMDITY 20% THEN THERMOSTAT HIGH

Hum

Mem

bers

hip

valu

e

THERMO

Mem

bers

hip

valu

e

20

0.6

20

0.3 0.3

25

The new thermo setting is 25 after this rule firesThe new thermo setting is 25 after this rule fires