12-05-2012, 05:38 PM
FUZZY LOGIC BASED SPEED CONTROL OF DC MOTOR USING 89C52 MICROCONTOLLER
[attachment=21961]
Objective:
The objective of this project is to develop fuzzy logic based speed control system for DC motor using 89C52 Microcontroller
Theory:
The speed of a DC motor depends on armature voltage and flux. If the field current is maintained constant, the speed is directly proportional to armature voltage. So by varying armature voltage, it is possible to control the speed of the motor.
Functioning:
In this project, motor field is excited by the fixed dc voltage obtained from uncontrolled rectifier. The armature is excited by a variable dc supply obtained from any one of the following motor drive.
a) Half/Full controlled bridge rectifier using SCRs.
b) Single quadrant chopper - using MOSFETs.
c) Four quadrant chopper -using MOSFETs.
The system has provision to set the required speed using keyboard. The Microcontroller computes the actual speed of the motor by counting pulses coming from proximity sensor. The Microcontroller compares set speed with the actual speed, and generates an error signal using Fuzzy logic/PID, which is then used to vary the duty ratio of the chopper to maintain the desired speed (in case to controlled rectifiers, the firing angle of SCRs are varied to maintain the desired speed). Thus the armature voltage is varied in order to achieve the desired speed.
Hardware:
The Hardware of this system has two parts,
Microcontroller section: This section includes 89C52 Microcontroller and 8279 - Keyboard/ Display interface and speed sensing circuit.
Power electronics section: This section includes uncontrolled rectifier using diodes and either controlled rectifier using SCRs or chopper using MOSFETs.
Choice of display:
Either Seven-segment display or LCD display.
Software:
Keil C language for programming 89C52 Microcontroller.
[attachment=21961]
Objective:
The objective of this project is to develop fuzzy logic based speed control system for DC motor using 89C52 Microcontroller
Theory:
The speed of a DC motor depends on armature voltage and flux. If the field current is maintained constant, the speed is directly proportional to armature voltage. So by varying armature voltage, it is possible to control the speed of the motor.
Functioning:
In this project, motor field is excited by the fixed dc voltage obtained from uncontrolled rectifier. The armature is excited by a variable dc supply obtained from any one of the following motor drive.
a) Half/Full controlled bridge rectifier using SCRs.
b) Single quadrant chopper - using MOSFETs.
c) Four quadrant chopper -using MOSFETs.
The system has provision to set the required speed using keyboard. The Microcontroller computes the actual speed of the motor by counting pulses coming from proximity sensor. The Microcontroller compares set speed with the actual speed, and generates an error signal using Fuzzy logic/PID, which is then used to vary the duty ratio of the chopper to maintain the desired speed (in case to controlled rectifiers, the firing angle of SCRs are varied to maintain the desired speed). Thus the armature voltage is varied in order to achieve the desired speed.
Hardware:
The Hardware of this system has two parts,
Microcontroller section: This section includes 89C52 Microcontroller and 8279 - Keyboard/ Display interface and speed sensing circuit.
Power electronics section: This section includes uncontrolled rectifier using diodes and either controlled rectifier using SCRs or chopper using MOSFETs.
Choice of display:
Either Seven-segment display or LCD display.
Software:
Keil C language for programming 89C52 Microcontroller.