For an effective control of the velocity of a DC servo motor, a microprocessor-based pulsewidth modulation (PWM) control system is developed. In the proposed design, the conventional hardware-based PWM signal generating circuit and proportional plus integral controller are replaced by MC68000 16 bit microprocessor software with a simple digital circuit, and also the conventional hardware-based current limiting circuit is replaced by a new current limiting software algorithm and current sensing circuit. It is found that the proposed control system shows simpler hardware structure and higher flexibility in implementation of control scheme.
To show effectiveness of the design, the microprocessor-based PWM controller is applied for the velocity control of R axis of KAISEM ROBOTl and the experimental results are presented.