Method of correction between electrical phase angle and mechanical output angle of stepper motor

A method for microstep triggering of a stepper motor, preferably a claw pole stepper motor, having a controller that outputs current or voltage pulses as a pulse train of a sinusoidal-like course to the stepper motor, as a result of which the rotor of the stepper motor rotates onward in microsteps, characterized in that the mechanical annular rotation (.tau..sub.m) of the stepper motor is detected by means of an angle encoder (encoder);

• that the controller forms the difference (.DELTA..tau..sub.m) between the electrical phase angle (.tau..sub.el) and the mechanical angle of rotation (.tau..sub.m) of the stepper motor;
• that from the difference (.DELTA..tau..sub.m) in accordance with a specified algorithm, the controller forms a corrected signal for the stepper motor, so that the controller first forms correction coefficients, at least one periodicity of the difference (.DELTA..tau..sub.m) is mapped on the correction coefficients, and the controller then with consideration of these correction coefficients forms the corrected signal for the stepper motor, which is used for further operation of the stepper motor;
• the controller includes correction coefficients for compensating for the hysteresis of the stepper motor;
• and the correction coefficients for the compensating of the hysteresis are varied in operation, using the measurement data of the angle encoder.