A STEPPING MOTOR DAMPING SYSTEM

• US 3,660,746 A
• Filed: 06/09/1970
• Issued: 05/02/1972
• Est. Priority Date: 06/09/1970
• Status: Expired due to Term

• Current Assignee: Seymour Electronics and Automation Incorporated
• Original Assignee: Donald L. Milek
• Inventors: Milek, Donald L.
• Primary Examiner(s): Simmons, G. R.
• Application Number:
  US05/045,172
• Time in Patent Office: 693 Days
• Field of Search: 318/696,685,138,254 310/49
• US Class Current: 318/696
• CPC Class Codes: G06K 13/20 Details
• CPC Class Codes: H02P 8/32 Reducing overshoot or oscillation, e.g. damping

Abstract

Method and apparatus for electronically damping a stepping motor to prevent the rotor from oscillating in advancing from position to position. The electronic damping includes digital circuits constructed and defined for advancing the rotor from position to position and while advancing, energizing all of the stator windings for a time interval less than the time period required to advance the rotor from position to position and yet of sufficient time duration to prevent the rotor from hunting when it arrives at its new position.

Claims

1. Control apparatus for a stepping motor comprising a plurality of energizable windings for advancing the rotor in response to the sequential energization of the stator windings, and circuit means for sequentially energizing the stator windings for advancing the rotor in response to the energization thereof, said circuit means including further circuit means for momentarily energizing all of the stator windings for a preselected time interval less than the time period required to advance the rotor from position to position and while the rotor is advancing from one position to the next, the preselected time interval being of a duration to electrically damp the rotor upon arrival at said next position.

2. Control apparatus for a stepping motor as defined in claim 1, wherein the circuit means includes counting means for providing output control signals for controlling the sequential energization of the stator windings and signal control means for stepping the counting means from count to count.

3. Control apparatus for a stepping motor as defined in claim 2, wherein said further circuit means comprises time delay means for providing a signal of a said preselected time interval for energizing all of the stator windings.

4. Control apparatus for advancing a record member, said apparatus comprising motor means adapted for advancing a record member coupled thereto, said motor means including a plurality of energizable winding means and a rotor, the energization of an individual winding means causing the advancement of the rotor and a record member coupled thereto, a source of control signals for providing output signals occurring at a rate related to the desired rate of advancement of a record member, counting means coupled to be responsive to the output signals from said source and providing output signals coupled to the energizable winding means for sequentially energizing the individual winding means for actuating the motor rotor in accordance with the count thereof, and winding control means coupled to be responsive to the control signals for providing an output signal to each of the energizable winding means for an interval less than the time required to advance the rotor from position to position and in coincidence with the Energization by the counting means of said individual winding means for damping the rotor in its advancement from position to position.

5. Control apparatus for incrementally advancing a record member having control information recorded thereon, and including means for sensing the control information as the record member advances and providing a control signal at each preselected increment of advancement of the record member, the improvement comprising stepping motor means coupled to the record member and adapted for linearly advancing the record member at said preselected increments, the motor means including a stator having individually energizable windings and a rotor magnetically coupled to the stator and responsive to the energization of the individual windings for rotating said preselected increment, binary signal generating means coupled to be responsive to the control signals derived from the record member and providing binary signals in response thereto, binary counting means coupled to be responsive to the binary signals for providing output signals coupled to individual windings of the motor means in accordance with each count thereof for the duration of the count, and anti-jitter control means coupled to be responsive to the binary signals for providing a winding energization signal of a preselecte duration less than the time period required to advance the rotor from position to position and at a preselected interval after the energization of the individual windings by the counting means to all of the winding means, the preselected interval being defined for reducing the oscillation of the rotor at each increment of advancement for positively advancing the record member.

6. Control apparatus for incrementally advancing a record member as defined in claim 5, wherein the binary counting means includes binary decoding means for decoding the pattern of output signals from the binary counting means for energizing the individual windings of the motor means in a predetermined sequence for linearly advancing the record member.

7. Control apparatus for incrementally advancing a record member as defined in claim 6, wherein the record member has a plurality of longitudinally aligned feed holes for generating the control signals corresponding to each of the feed holes, and the motor means includes a sprocket wheel coupled to be rotatable with the motor rotor and engaging a feed hole for advancing the record member with the advancement of the rotor, said binary signal generating means including means for controlling the repetition rate of the binary signals in accordance with the desired rate of advancement of the record member.

8. Control apparatus for incrementally advancing a record member as defined in claim 7, wherein the counting means is a bi-directional counter and includes means for controlling the direction of counting in accordance with the desired direction of travel of the record member.

9. Control apparatus for incrementally advancing a record member as defined in claim 7, wherein the means for controlling the repetition rate of the binary signals includes means for controlling the rate of advancement of the record member for sensing the information on the record member and means for controlling the rate of advancement without sensing the record member.

10. A method of controlling a stepping motor including a rotor and a stator having a plurality of energizable windings spaced around the rotor for incrementally rotating the rotor in accordance with the energization of the stator windings, the method including the steps of sequentially energizing an individual winding of the stepping motor to cause the rotor to magnetically snap into alignment with the energized winding and thereby incrementally rotate the rotor in accordance with the sequential energization of the windings, and during the interval an individual winding is energized and while the rotor is advancing between stator poles momentarily energizing all of The windings of the stator for a time interval less than the time period required to advance the rotor from position to position and of sufficient time duration to prevent the rotor from hunting.

11. A method of controlling a stepping motor including a rotor having a plurality of magnetic poles defined thereon and a stator having a corresponding plurality of energizable windings spaced around the rotor, the windings being divided into spaced groups of different phases for defining stator poles with the adjacent windings of each group arranged for defining poles of opposite polarity and the windings of the same phase in each group being connected together whereby the sequential energization of the stator windings in each group causes the rotor to magnetically align with the energized winding and the stator pole defined thereby to incrementally rotate the rotor, the method including the steps of sequentially energizing an individual winding of each group for incrementally advancing the rotor, a preselected interval after an individual winding of each group is energized and during the time the rotor is advancing between stator poles, energizing the adjacent windings of each group for a preselected interval less than the time period required to advance the rotor from position to position, and maintaining the energization of said individual windings after the preselected interval to cause the rotor to incrementally advance without producing settling in oscillations.