CORRECTION PROCESS BETWEEN THE ELECTRIC PHASE ANGLE AND MECHANICAL OUTPUT ANGLE OF A STEP MOTOR

摘要

A process is disclosed for correcting a non-linear relation between the electric phase angle and the mechanical output angle of step motors by using a low resolution encoder or the like. This process represents a compromise between the classical regulation of step motors, that requires a high resolution angle detection, and a purely statistical correction of the characteristic curve. The result is a substantial synchronism improvement, for example when conventional claw pole step motors are used for driving the pointer of a display in a motor vehicle. The micro-step control is carried out with a corrected sine wave form. Coefficients evaluated by simplified Fourier synthesis are essentially used to correct the sine wave form.