Abstract
A microstepping method, in which a sinusoidally varying current is supplied to each filed coil with a different phase to shift a stagnation point with a smaller step relative to a full step, has an advantage over conventional stepping process. By this control technique an elimination of vibration and a realization of higher resolution are expected. However in reality, due to a distorsion of driving torque distribution, the microstepping angle is not uniform and a troublesome try and cut procedure is necessary in individual application. In this paper the microstepping behavior is treated by the Spanworm equation, and the possibility of an analytical designing procedure for this microstepping system is shown.
