Microstep of digital control for step motor and its test using a laser interferometer measurement system

Abstract

By using the pole-interpolation method, the driver can generate four-phase sinusoidal/ramp current for microstep to control the step motor's rotation. This paper decribes the improvement of techniques to increase the resolution from 200 steps per revolution (s.p.r.) to 12,800 s.p.r., the improvement performance of the motor such as overshoot and uniform step displacement, and obtain a more accurate measurement for each micro-step by a new design of laser interferometer measurement system. A peak detector is incorporated with it in order to eliminate the effect of rotor's vibration at the stopped point during each measurement. The measuring data has been analysed with sample variances calculated, from which three different cases of measurements are compared with each other.

Additional information

Notes on contributors

HAO-YUNG LO

This work was done while the author was visiting at the Computer Engineering Department, University of Minnesota, Duluth, MN 55812, U.S.A.