US4091316A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for damping stepper motors
Assignee: Prime Computer Inc
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Filing: 1975-09-30
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Granted: 1978-05-23
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Expires: 1995-09-30
Abstract
Abstract A method and apparatus for damping stepper motors are disclosed. A tachometer feedback is used to modulate the phase angle of the stepper motor command currents to achieve damping.
Inventors
- 👤 David Friedman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:37
CPC Classifications
H; H02; H02P; H02P8/00; H02P8/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
66 words
A method for damping a plural phase, incrementally driven stepper motor independently of the load thereon, said method comprising the steps of: (1) generating command currents for driving the stepper motor; (2) generating a signal representing the shaft velocity error of the stepper motor; and, (3) altering the phase angle of the command currents relative to their normal positions in response to said velocity error signal.
Claim 2
Independent Claim
66 words
A method for damping a plural phase, incrementally driven stepper motor independently of the load thereon, said method comprising the steps of: (1) generating command currents for driving the stepper motor; (2) generating a signal representing the shaft velocity error of the stepper motor; and, (3) altering the phase angle of the command currents relative to their normal positions in response to said velocity error signal.
Claim 3
Independent Claim
153 words
A method for damping a two phase, incrementally driven stepper motor independently of the load thereon, said method comprising the steps of: (1) generating phase ONE and phase TWO command currents φ 1 and φ 2 , respectively, for driving the stepper motor; (2) generating a signal V err representing the shaft velocity error of the stepper motor; (3) multiplying the command current φ 2 and the velocity signal V err together and then adding the resultant to the φ 1 command current to produce a correctional feedback current φ 1 ' = φ 1 + V err φ 2 for the phase ONE drive; and, (4) multiplying the command current φ 1 and the velocity signal V err together and then adding the resultant to the φ 2 command current to produce a correctional feedback current φ 2 ' = φ 2 - V err φ 1 for the phase TWO drive.
Claim 4
Independent Claim
153 words
A method for damping a two phase, incrementally driven stepper motor independently of the load thereon, said method comprising the steps of: (1) generating phase ONE and phase TWO command currents φ 1 and φ 2 , respectively, for driving the stepper motor; (2) generating a signal V err representing the shaft velocity error of the stepper motor; (3) multiplying the command current φ 2 and the velocity signal V err together and then adding the resultant to the φ 1 command current to produce a correctional feedback current φ 1 ' = φ 1 + V err φ 2 for the phase ONE drive; and, (4) multiplying the command current φ 1 and the velocity signal V err together and then adding the resultant to the φ 2 command current to produce a correctional feedback current φ 2 ' = φ 2 - V err φ 1 for the phase TWO drive.
Claim 5
Dependent Claim
31 words
The method of claim 2 wherein said velocity signal V err is passed through a high pass filter before being multiplied with said command currents φ 1 and φ 2 .
Claim 6
Dependent Claim
61 words
In a plural phase, incrementally driven stepper motor, an apparatus for damping the stepper motor independently of the load thereon, said apparatus comprising: (1) means for generating a signal representing the shaft velocity error of the stepper motor; and, (2) means responsive to said velocity signal for altering the phase of the stepper motor command currents relative to their normal position.
Claim 7
Dependent Claim
61 words
In a plural phase, incrementally driven stepper motor, an apparatus for damping the stepper motor independently of the load thereon, said apparatus comprising: (1) means for generating a signal representing the shaft velocity error of the stepper motor; and, (2) means responsive to said velocity signal for altering the phase of the stepper motor command currents relative to their normal position.
Claim 8
Dependent Claim
78 words
In a two phase, incrementally driven stepper motor, an apparatus for damping the stepper motor independently of the load thereon, said apparatus comprising: (1) means for generating a signal V err representing the shaft velocity error of the stepper motor; and, (2) means responsive to the velocity signal V err for altering the phase angle of the stepper motor phase ONE command current φ 1 and the phase TWO command current φ 2 relative to their normal positions.
Claim 9
Dependent Claim
78 words
In a two phase, incrementally driven stepper motor, an apparatus for damping the stepper motor independently of the load thereon, said apparatus comprising: (1) means for generating a signal V err representing the shaft velocity error of the stepper motor; and, (2) means responsive to the velocity signal V err for altering the phase angle of the stepper motor phase ONE command current φ 1 and the phase TWO command current φ 2 relative to their normal positions.
Claim 10
Dependent Claim
144 words
The apparatus of claim 5 wherein said velocity signal V err generating means comprises a tachometer and said responsive means comprises: (1) a multipler for multiplying the velocity signal with the command currents φ 1 and φ 2 to produce resultants V err · φ 1 and V err · φ 2 respectively; (2) a first summing means for adding the φ 1 command current and the V err · φ 2 resultant to produce a correction feedback current φ 1 ' = φ 1 + V err φ 2 for driving phase ONE of the stepper motor; and, (3) a second summing means for adding the φ 2 command current and the V err · φ 1 resultant to produce a correction feedback current φ 2 ' = φ 2 - V err φ 1 for driving phase TWO of the stepper motor.
Claim 11
Dependent Claim
29 words
The apparatus of claim 6 further comprising high pass filter means for filtering the V err signal before multiplication with the command currents φ 1 and φ 2 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |