Solved–Assignment 4 –Solution

Description

1. [10 marks] A fuzzy system is used to control the temperature in a room. The inputs to the controller are the ‘Temperature’ and ‘Temperature change’. The outputs are the ‘Fan Speed’ and ‘Heater power’. The membership functions are shown in the following figures

and the rule base is described by the following table

LOW MEDIUM HIGH
NEG LOW/ON ON/LOW MEDIUM/ON
ZERO LOW/ON LOW/OFF MEDIUM/OFF
POS LOW/OFF MEDIUM/OFF HIGH/OFF

If the temperature is 22°C and the change of temperature is 4°C/hr, answer the following questions:

a) What is the result of fuzzification of those inputs?

b) Use the rules and Mamdani inference to specify the output fuzzy membership functions.

c) Calculate the ‘Heater power’ and ‘Fan speed’ using your choice of defuzzification method.