Digital stepping motor control system

Claim 2

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position in the forward direction and producing the same output signals at the same rotor positions as the rotor moves back in the reverse direction from a maximum point X of oscillation in the forward direction in which X is equal to or more than (Y X Z*) but is less than (X + Z*) where Y is an even integer greater than or equal to 4 and Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in said forward direction until the point of maximum oscillation and then until the rotor returns to a point of S-Z* measured from home position where S is a switch point equal to (X + 2Z*)/2, and means under the control of said emitter for providing said forward energization signal at said switch point S and said rotor is moving back in the reverse direction toward home position from its point of maximum oscillation.

Claim 3

The combination as set forth in claim 1 and including means for terminating said forward energization signal in a predetermined time after said rotor passes through its Z* position measured from said home position in moving back toward its home position from its point of maximum oscillation.

Claim 4

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position moving in the forward direction and producing the same output signals at the same rotor positions as the rotor moves back in the reverse direction from a maximum point X of oscillation in the forward direction in which X is equal to or more than (Y X Z*) but is less than (X + Z*) where Y is an odd integer greater than or equal to 3 and Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in the forward direction until its point of maximum oscillation and then until said rotor returns to a point S-Z* measured from home position where S is a switch point equal to (X + 3Z*)/2, and means under the control of said emitter for providing said forward energization signal at said switch point S as said rotor is moving back in the reverse direction toward home position from its point of maximum oscillation.

Claim 5

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position moving in the forward direction and producing the same output signals at the same rotor positions as the rotor moves back in the reverse direction from a maximum point X of oscillation in the forward direction in which X is equal to or more than (Y X Z*) but is less than (X + Z*) where Y is an odd integer greater than or equal to 3 and Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in the forward direction until its point of maximum oscillation and then until said rotor returns to a point S-Z* measured from home position where S is a switch point equal to (X + 3Z*)/2, and means under the control of said emitter for providing said forward energization signal at said switch point S as said rotor is moving back in the reverse direction toward home position from its point of maximum oscillation.

Claim 6

The combination as set forth in claim 3 and including means for terminating said forward energization signal in a predetermined time after said rotor passes through its Z* position measured from said home position in moving back toward its home position from its point of maximum oscillation.

Claim 7

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing in the forward direction through its desired or home position and producing the same output signals at the same rotor positions as the rotor moves back reversely from a maximum point of oscillation X which is equal to or more than 2Z* but is less than 3Z* where Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in the forward direction until its point of maximum oscillation and then until Z* measured from home position as the rotor returns from its point of maximum oscillation toward home position, and means under the control of said emitter for providing said forward energization signal at 2Z* measured from home position and subsequent to the point of maximum oscillation of said rotor as the rotor returns toward home position travelling in the reverse direction.

Claim 8

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing in the forward direction through its desired or home position and producing the same output signals at the same rotor positions as the rotor moves back reversely from a maximum point of oscillation X which is equal to or more than 2Z* but is less than 3Z* where Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in the forward direction until its point of maximum oscillation and then until Z* measured from home position as the rotor returns from its point of maximum oscillation toward home position, and means under the control of said emitter for providing said forward energization signal at 2Z* measured from home position and subsequent to the point of maximum oscillation of said rotor as the rotor returns toward home position travelling in the reverse direction.

Claim 9

The combination as set forth in claim 5 and including means for terminating said forward energization signal after a predetermined time subsequent to the passage of said rotor through a point at Z* spaced from home position as the rotor is moving reversely toward home position.

Claim 10

The combination as set forth in claim 6, said means for terminating said forward energization signal including a single shot for providing a timing action.

Claim 11

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing in the forward direction through its desired or home position and producing the same output signals at the same rotor positions as the rotor moves back reversely from a maximum point of oscillation which is equal to or more than Z* but is less than 2Z* where Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in the forward direction until its point of maxiMum oscillation and then as the rotor reverses direction, and means for terminating said reverse energization signal when said rotor reaches its Z* position spaced from home position as the rotor moves in the reverse direction from its point of maximum oscillation toward its home position.

Claim 12

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing in the forward direction through its desired or home position and producing the same output signals at the same rotor positions as the rotor moves back reversely from a maximum point of oscillation which is equal to or more than Z* but is less than 2Z* where Z is a constant, means under the control of said emitter for providing said reverse energization signal when said rotor passes through its home position moving in the forward direction until its point of maxiMum oscillation and then as the rotor reverses direction, and means for terminating said reverse energization signal when said rotor reaches its Z* position spaced from home position as the rotor moves in the reverse direction from its point of maximum oscillation toward its home position.

Claim 13

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position moving in the forward direction and producing the same output signals as the rotor moves back in the reverse direction from a maximum point of oscillation X which in this case is less than Z* from home position, means under the control of said emitter for initiating said reverse energization signal when said rotor passes through its home position moving in the forward direction, and means for terminating said reverse energization signal a predetermined time after its initiation.

Claim 14

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing successive output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position moving in the forward direction and producing the same output signals as the rotor moves back in the reverse direction from a maximum point of oscillation X which in this case is less than Z* from home position, means under the control of said emitter for initiating said reverse energization signal when said rotor passes through its home position moving in the forward direction, and means for terminating said reverse energization signal a predetermined time after its initiation.

Claim 15

The combination as set forth in claim 1, said two last-named means under the control of said emitter including an overshoot counter and a divide-by-two counter both supplied with output signals from said emitter, and a compare circuit having outputs of said divide-by-two counter and said overshoot counter supplied to it as inputs and thus providing a signal output when there is a correspondence of outputs of said two counters, and a circuit responsive to the output of said compare circuit to in turn control said two energization signals.

Claim 16

The combination as set forth in claim 3, said two last-named means under the control of said emitter including an overshoot counter and a divide-by-two counter both supplied with output signals from said emitter, and a compare circuit having outputs of said divide-by-two counter and said overshoot counter supplied to it as inputs and thus providing a signal output when there is a correspondence of outputs of said two counters, and a circuit responsive to the output of said compare circuit to in turn control said two energization signals.

Claim 17

The combination as set forth in claim 5, said two last-named means under the control of said emitter including an overshoot counter and a divide-by-two counter both supplied with output signals from said emitter, and a compare circuit having outputs of said divide-by-two counter and said overshoot counter supplied to it as inputs and thus providing a signal output when there is a correspondence of outputs of said two counters, and a circuit responsive to the output of said compare circuit to in turn control said two energization signals.

Claim 18

The combination as set forth in claim 8, said means for terminating said reverse energization signal including an overshoot counter and a divide-by-two counter both responsive to the outputs of said emitter and a compare circuit having the outputs of said two counters as inputs and providing a signal output when the outputs of said two counters are identical.

Claim 19

The combination as set forth in claim 9, said means for terminating said reverse energization signal including a single shot for providing a timing action.

Claim 20

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position in the forward direction and producing the same output signals at the same rotor positions as the rotor moves back in the reverse direction, means under the control of said emitter for providing said reverse energization signal so as to thereby apply torque on said rotor in the reverse direction when said rotor passes through its home position moving in the forward direction until the point of maximum oscillation of the rotor and then until the rotor returns to a reverse torque termination point which is between said point of maximum oscillation and said home position, and means under the control of said emitter effective at a forward torque initiating point of rotor rotation lying between said point of maximum oscillation of the rotor and said reverse torque termination point of the rotor for providing said forward energization signal and thereby applying torque on said rotor in the forward direction as said rotor is moving back in the reverse direction toward home position from its point of maximum oscillation whereby there is an overlapping forward torque on said rotor and reverse torque on said rotor between said forward torque initiating and said reverse torque termination points of rotor rotation.

Claim 21

In combination, an electric motor of the stepping type having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, means for energizing said windings to apply torque on said rotor in a forward direction when supplied with a forward energization signal, means for energizing said windings to apply torque on said rotor in a reverse direction when supplied with a reverse energization signal, an emitter driven by said rotor for producing output signals as said rotor moves through successive increments each of Z* after passing through its desired or home position in the forward direction and producing the same output signals at the same rotor positions as the rotor moves back in the reverse direction, means under the control of said emitter for providing said reverse energization signal so as to thereby apply torque on said rotor in the reverse direction when said rotor passes through its home position moving in the forward direction until the point of maximum oscillation of the rotor and then until the rotor returns to a reverse torque termination point which is between said point of maximum oscillation and said home position, and means under the control of said emitter effective at a forward torque initiating point of rotor rotation lying between said point of maximum oscillation of the rotor and said reverse torque termination point of the rotor for providing said forward energization signal and thereby applying torque on said rotor in the forward direction as said rotor is moving back in the reverse direction toward home position from its point of maximum oscillation whereby there is an overlapping forward torque on said rotor and reverse torque on said rotor between said forward torque initiating and said reverse torque termination points of rotor rotation.

Claim 22

In combination, a stepping motor having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, an emitter driven with said rotor and arranged to produce output signals at rotor positions between said natural detent positions and with the output signals of the emitter being dependent on the direction of rotor rotation, forward energizing means for energizing said windings so as to provide a forward torque on said rotor, reverse energizing means for energizing said windings so as to provide a reverse torque on said rotor, means under the control of any of said emitter output signals produced at rotor positions between said natural detent positions and denoting a forward position of the rotor from a home position of the rotor for controlling said reverse energizing means to return the rotor toward the home position from the forward rotor position, and means under the control of any of said emitter output signals produced at rotor positions between said natural detent positions and denoting a reverse position of the rotor from a home position of the rotor for controlling said forward energizing means to return the rotor toward the home position from the reverse rotor position.

Claim 23

In combination, a stepping motor having a stator with a set of discrete poles and a rotor having a set of discrete poles with electrical windings on one of said sets of poles so that said rotor has a plurality of natural detent positions in which said rotor poles are aligned with poles of said stator or are between poles of said stator in a symmetrical relationship therewith when various of said windings are energized, an emitter driven with said rotor and arranged to produce output signals at rotor positions between said natural detent positions and with the output signals of the emitter being dependent on the direction of rotor rotation, forward energizing means for energizing said windings so as to provide a forward torque on said rotor, reverse energizing means for energizing said windings so as to provide a reverse torque on said rotor, means under the control of any of said emitter output signals produced at rotor positions between said natural detent positions and denoting a forward position of the rotor from a home position of the rotor for controlling said reverse energizing means to return the rotor toward the home position from the forward rotor position, and means under the control of any of said emitter output signals produced at rotor positions between said natural detent positions and denoting a reverse position of the rotor from a home position of the rotor for controlling said forward energizing means to return the rotor toward the home position from the reverse rotor position.

Claim 24

The combination as set forth in claim 16 in which said electrical windings are disposed on poles of said stator.

Claim 25

The combination as set forth in claim 17, said forward energizing means and said reverse energizing means including switching means for switching energization of the windings on said stator under the control of output signals from said emitter.

Claim 26

The combination as set forth in claiM 16 and including a master position counter responsive to output signals from said emitter for indicating the present position of said rotor, a desired position register the contents of which are indicative of the desired or home position of the rotor, and compare circuitry for comparing the contents of said counter and register and effective for controlling said forward energizing means and said reverse energizing means.