Fuzzy Logic Based Dryer Controller

Abstract

The fuzzy logic control system determines the real-world constraint of the dryer’s heating rate to the dryer driver circuit which is constructed with the pulse width modulation (PWM) technique. Input and output operations to and from the computer system are carried out via parallel interfacing and Turbo C++ programming. The humidity sensing circuit is constructed around a 555 timer with astable operation which is a non-sinusoidal oscillator. This humidity sensing circuit produces a rectangular wave with the frequency indirectly proportional to the sensed humidity. In order to achieve the perfectively symmetrical square wave as well as to reduce the frequency value, the clocked flip-flop, CD4017BC that is divided by 10 Johnson counter with 10 decoded outputs and a carry out bit is added to the timer’s output. The resultant frequency is applied into the computer system integrating with the fuzzy logic and it determines the frequency value and its rate of change which are input to the fuzzy logic control system.