Position Hysteresis Error Reduction in Stepper Motors Using Dither Currents During Microstepping
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
Position hysteresis error in stepper motors can be caused by magnetic hysteresis and/or mechanical friction. The position hysteresis error becomes larger during microstepping than in regular stepping, even though the driving and loading conditions remain the same. The position hysteresis error can be substantially reduced, for example to less than half, by dithering the motor currents about the nominal values during microstepping. The method does not require any changing of the mechanical design of the stepper motor and still retains the convenience of open loop control. The only modification required is the electronic motor control circuit to apply the dither currents.