Novel microstepping control methods for electromagnetic micromotors with star-connected winding

This paper presents two novel microstepping control methods specially designed for electromagnetic micromotors with star-connected winding. The details of the micromotor structure are described. Two microstepping methods, virtual coil and torque-synthesis current division methods, have been developed to realize the accuracy position precision control. Electrical design instead of mechanical design is adopted to overcome the present difficulty in machining a micro stepper motor. Some initial results in the real microrobot system which driven by the electromagnetic micromotor are given to show the performance of these methods.