Damping Control of Stepping Motors Using Feedback of Back EMF

Abstract

A new method to improve the damping of stepping motors is proposed. The idea is to utilize the information on position and velocity contained in the back electromotive force (BEMF) induced in the coils. This information is extracted with a simple analog circuit and processed by a feedback controller. The performance of stepping motors can thus be improved at low cost, e. g. by increasing the mechanical damping characteristics of the rotor. Theoretical studies and experimental work are presented. A reduction of settling time from 120 ms to 5 ms has been obtained.