A Tunable Fuzzy Logic Engine

by Richard Sevenich and Paul Leathers

Listing One

/* declare an input domain  */
input domain TIME    

/* define sets within TIME domain */
TIME EARLY_AM is  {0 0 6 7}
TIME MORNING is   {6 7 11 12}
TIME AFTERNOON is {11 12 16 17}
TIME EVENING is   {16 17 19 20}
TIME NIGHT is     {19 20 24 24}

/* declare another input domain  */
input domain TEMPERATURE      

/* define sets within TEMPERATURE domain */
COLD is  {0 0 40 50}
COOL is  {40 50 60 70}
WARM is  {60 70 80 90}
HOT is   {80 90 100 100}

/* declare an output domain */
output domain FAN_SPEED  

/* define sets within FAN_SPEED */
OFF is    {-5 0 0 5}
LOW is     {0 5 10 20}  
MEDIUM is {10 20 30 40}  
HIGH is   {30 40 50 50}  

/* some possible rules associated with the      */
/* preceding inputs and outputs - not a         */
/* complete selection of rules, merely examples */

if TEMPERATURE is HOT or TEMPERATURE is very WARM  
then FAN_SPEED is very HIGH        

if TEMPERATURE is COLD or (TEMPERATURE is COOL and TIME is 
EVENING)then FAN_SPEED is OFF

if TEMPERATURE is COOL or TIME is MORNING
then FAN_SPEED is LOW

if TEMPERATURE is WARM or (TEMPERATURE is COOL and TIME is 
MORNING) then FAN_SPEED is MEDIUM

Listing Two

 ...
if TEMPERATURE is HOT or TEMPERATURE is very WARM  
then FAN_SPEED is very HIGH        

input domain TEMPERATURE      
COLD is  {0 0 40 50}
COOL is  {40 50 60 70}
WARM is  {60 70 80 90}      
HOT is   {80 90 100 100}

Listing Three

 ...
Listing Three
ERROR at line 25, Unknown domain: <>

Listing Four

COOL is  {40 50 60 30}
WARM is  {70 60 80 90}

Listing Five

Listing Five
ERROR at line 13, set <> begins at 40, ends at 30
ERROR at line 14, set <> begins at 70, max at 60

Listing Six

if TEMPERATURE is HOT or TEMPERATURE is very HIGH 
then FAN_SPEED is very HIGH

Listing Seven

ERROR at line 21, Unknown <> set: <>

Listing Eight

if TEMPERATURE is HOT then FAN_SPEED is HIGH

Listing Nine

if TEMPERATURE is HOT AND FAN_SPEED is HIGH
  then DELTA_TEMPERATURE is NEGATIVE_SMALL

Listing Ten

input domain temperature
cold is {20 40 50 60}
cool is {50 60 65 75}
warm is {65 75 80 90}
hot is {80 90 100 100}

output domain fan_speed
off is {-10 0 0 10}
low is {0 10 10 20}
med is {10 20 20 30}
high is {20 30 30 40}

if temperature is cold then fan_speed is off
if temperature is cool then fan_speed is low
if temperature is warm then fan_speed is med
if temperature is hot then fan_speed is high

Listing Eleven

input domain temperature
cold is {20 40 50 60}
cool is {50 60 65 75}
warm is {65 75 80 90}
hot is {80 90 100 100}

input domain fan_speed
off is {0 0 0 0}
low is {0 10 10 20}
med is {10 20 20 30}
high is {20 30 30 40}

output domain delta_temperature
nm is {-15 -10 -10 -5}
zero is {-5 0 0 5}
ps is {0 5 5 10}
pm is {5 10 10 15}
pl is {10 15 20 20}

if temperature is cold and fan_speed is off
then delta_temperature is ps

if temperature is cold and 
(fan_speed is low or fan_speed is med or fan_speed is high)
then delta_temperature is zero

if temperature is cool and fan_speed is off
then delta_temperature is pm

if temperature is cool and fan_speed is low
then delta_temperature is ps

if temperature is cool and (fan_speed is med or fan_speed is high)
then delta_temperature is zero

if (temperature is warm or temperature is hot) and fan_speed is off
then delta_temperature is pl

if (temperature is warm or temperature is hot) and fan_speed is low
then delta_temperature is pm

if (temperature is warm or temperature is hot) and fan_speed is med
then delta_temperature is ps

if (temperature is warm or temperature is hot) and fan_speed is high
then delta_temperature is nm

End Listings