Microprocessor based prototype design of a PMDC motor with its system identification and PI controller design

Abstract

This paper describes the development process of a permanent magnetic direct current (PMDC) motor prototype in details. The designed prototype is used for speed control purposes. The developed model is intended to have two types of inputs: one is analog input which accepts variable direct voltage for system identification purpose, and the other is the pulse width modulation input, which can be used to interface with the outside world such as microcontrollers or programmable logic controllers. A microprocessor (with 8 bit resolution and a high performance RISC CPU) acts as a core of the module as it accepts the inputs and accordingly provides the output. An IR sensor acts as feedback sensor and provides pulses to the microprocessor which performs frequency to voltage (F/V) converting function and gives a variable output direct voltage as the speed of the motor varies. The actuator is a permanent magnetic direct current motor driven using metal oxide semiconductor field effect transistor based driving circuit. A four stages magnetic load mechanism is attached to the motor shaft. For test experiment, an ARDUINO MEGA MATLAB SIMULINK support package-based module is developed to provide the inputs and measure the outputs, then open loop test, system identification and PI controller design are carried out and satisfying results are obtained. Illustrating the detailed procedure and the step by step work of the design process of the PMDC motor prototype is the main contribution of current work.