Sensorless position control of stepper motor

Stepper motors are widely used to perform accurate position control. Even if they provide satisfactory solutions in open-loop control under limited conditions, they are commonly controlled by a closed-loop system with a speed sensor for high performance dynamic operation. With the development of control methods and semiconductor technology, there have been a lot of research to eliminate encoders which are the expensive part of motor control applications. In this study, two phase permanent magnet stepper motor drive system is experimentally established without using any mechanical sensor. Motor is driven by microstepping technique with the aid of a microcontroller. Phase currents are measured by a data acquisition card and obtained datas are transferred into MATLAB software, then the position of motor is estimated by Kalman filter, using mathematical model of motor. After position information is reached, experimental studies of closed-loop position control of motor were carried out with P and PI controller, following simulation of same system.