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US3667031A
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Phase-locked resolver tracking system
Assignee: Massachusetts Institute of Technology
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Filing: 1970-08-18
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Granted: 1972-05-30
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Expires: 1990-08-18
Abstract
Abstract An improved phase-locked feedback loop which functions in conjunction with a resolver as an efficient and highly accurate tracking system for continually tracking the angle information in modulated resolver output waveforms. The improvement basically comprises a phase-locked loop incorporating as many phasesensitive detectors as there are resolver outputs, each detector operating on one of the output windings of the resolver, the circuit being configured so as to provide resolver-angle to phase-angle conversion with substantially increased accuracy and performance improvement.
Inventors
- 👤 Duncan B Cox Jr
- 👤 Kenneth Fertig
- 👤 Donald E Fulton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:00
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/087
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
188 words
A phase-locked tracking system for continuously tracking modulated output waveforms, said tracking system comprising in combination: a. resolving means having at least one input, excited by at least one first excitation signal and generating at least two modulated output waveforms; b. at least two phase-sensitive detectors, each of said detectors having a first input and a second input, wherein said first input is adapted to receive one of said modulated output waveforms and said second input is adapted to receive a second excitation signal, each of said detectors generating an error voltage that is a product of said modulated output waveform and said second excitation signal; c. a summer coupled to said phase-sensitive detectors for summing said error voltages and producing a resulting error voltage; d. a voltage-controlled oscillator coupled to said summer and generating at least one tracking signal, the output phase of said tracking signals being controlled by said resulting error voltage so as to minimize said resulting error voltage; and e. means of selectively coupling said tracking signals to one of said inputs of said resolving means and said second inputs of said phase-sensitive detectors.
Claim 2
Dependent Claim
188 words
A phase-locked tracking system for continuously tracking modulated output waveforms, said tracking system comprising in combination: a. resolving means having at least one input, excited by at least one first excitation signal and generating at least two modulated output waveforms; b. at least two phase-sensitive detectors, each of said detectors having a first input and a second input, wherein said first input is adapted to receive one of said modulated output waveforms and said second input is adapted to receive a second excitation signal, each of said detectors generating an error voltage that is a product of said modulated output waveform and said second excitation signal; c. a summer coupled to said phase-sensitive detectors for summing said error voltages and producing a resulting error voltage; d. a voltage-controlled oscillator coupled to said summer and generating at least one tracking signal, the output phase of said tracking signals being controlled by said resulting error voltage so as to minimize said resulting error voltage; and e. means of selectively coupling said tracking signals to one of said inputs of said resolving means and said second inputs of said phase-sensitive detectors.
Claim 3
Dependent Claim
18 words
The phase-locked tracking system of claim 1 further including a filter coupled to said summer and voltage-controlled oscillator.
Claim 4
Dependent Claim
37 words
The phase-locked tracking system of claim 1 wherein said resolving means is excited by two excitation signals in time-quadrature and generates two phase-modulated output waveforms, one lagging the other by 90*, said system comprising two phase-sensitive detectors.
Claim 5
Dependent Claim
29 words
The phase-locked tracking system of claim 1 wherein said resolving means is excited by one excitation signal and generates two resolver-modulated output waveforms, said system comprising two phase-sensitive detectors.
Claim 6
Dependent Claim
27 words
The phase-locked tracking system of claim 1 wherein said tracking signals are coupled to said second inputs of said phase-sensitive detectors, thereby constituting said second excitation signals.
Claim 7
Dependent Claim
26 words
The phase-locked tracking system of claim 1 wherein said tracking signals are coupled to said inputs of said resolving means, thereby constituting said first excitation signals.
Claim 8
Dependent Claim
14 words
The phase-locked tracking system of claim 1 wherein said resolving means is a resolver.
Claim 9
Dependent Claim
188 words
A phase-locked resolver tracking system for continuously tracking the modulated resolver output waveforms, said tracking system comprising in combination: a. a resolver having at least one input, excited by at least one first excitation signal and generating at least two modulated output waveforms; b. two phase-sensitive detectors, each of said detectors having a first input and a second input, wherein said first input is adapted to receive one of said modulated output waveforms and said second input is adapted to receive a second excitation signal, each of said detecTors generating an error voltage that is a product of said modulated output waveform and said second excitation signal; c. a summer coupled to said phase-sensitive detectors for summing said error voltages and producing a resulting error voltage; d. a voltage-controlled oscillator coupled to said summer and generating at least one tracking signal, the output phase of said tracking signals being controlled by said resulting error voltage so as to minimize said resulting error voltage; and e. means of selectively coupling said tracking signals to one of said inputs of said resolver and said second inputs of said phase-sensitive detectors.
Claim 10
Dependent Claim
188 words
A phase-locked resolver tracking system for continuously tracking the modulated resolver output waveforms, said tracking system comprising in combination: a. a resolver having at least one input, excited by at least one first excitation signal and generating at least two modulated output waveforms; b. two phase-sensitive detectors, each of said detectors having a first input and a second input, wherein said first input is adapted to receive one of said modulated output waveforms and said second input is adapted to receive a second excitation signal, each of said detecTors generating an error voltage that is a product of said modulated output waveform and said second excitation signal; c. a summer coupled to said phase-sensitive detectors for summing said error voltages and producing a resulting error voltage; d. a voltage-controlled oscillator coupled to said summer and generating at least one tracking signal, the output phase of said tracking signals being controlled by said resulting error voltage so as to minimize said resulting error voltage; and e. means of selectively coupling said tracking signals to one of said inputs of said resolver and said second inputs of said phase-sensitive detectors.
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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |