US3721497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ring laser gyroscope linearization system
Assignee: Boeing North American Inc
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Filing: 1971-04-19
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Granted: 1973-03-20
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Expires: 1991-04-19
Abstract
Abstract The invention is directed to a system which operates in combination with a ring laser type gyroscope having an output defined by the equation psi Omega 30 Omega L sin ( psi + Epsilon ) such that the system drives the term Epsilon to zero. In the equation Omega is the input rotation rate of the ring laser gyroscope, Omega L is the lock-in rate or that rate below which no output is obtained due to frequency entrainment of the two optical oscillators, psi is the instantaneous phase difference between the two optical oscillators and Epsilon is the phase angle at time, t, equal to zero. Additional electronic circuits then allow the complete term to be reduced to zero.
Inventors
- 👤 S Shutt
- 👤 T Hutchings
- 👤 J Hoffman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:33
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/081; H01S3/083; G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; G01C19/661; G01C19/665
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
140 words
In combination with a ring laser gyroscope having as an output two counter rotating beams, a linearizing system comprised of: drive means interposed in the optical path of one of said output beams for changing the optical path of said beam in response to a control signal; combining means for combining the other of said output beams with the output beam from said drive means; detector means for converting said combined optical beam into an AC signal; and comparing means receiving said AC signal from said detector means and for providing said control signal to said drive means which signal is proportional to the average of said AC signal for at least 1 cycle of time, whereby said control signal activates said drive means to change the optical path of said one output beam to reduce the average towards zero.
Claim 2
Dependent Claim
140 words
In combination with a ring laser gyroscope having as an output two counter rotating beams, a linearizing system comprised of: drive means interposed in the optical path of one of said output beams for changing the optical path of said beam in response to a control signal; combining means for combining the other of said output beams with the output beam from said drive means; detector means for converting said combined optical beam into an AC signal; and comparing means receiving said AC signal from said detector means and for providing said control signal to said drive means which signal is proportional to the average of said AC signal for at least 1 cycle of time, whereby said control signal activates said drive means to change the optical path of said one output beam to reduce the average towards zero.
Claim 3
Dependent Claim
41 words
The linearizing system according to claim 1 wherein said drive means is comprised of: a mirror; and a piezoelectric driver affixed to the rear of said mirror with said mirror positioned to deflect said one output beam to said combining means.
Claim 4
Dependent Claim
46 words
The linearizing system according to claim 1 and further comprising: clock means providing a continuous train of pulses to said comparing means for comparison against said received AC signAl such that the symmetrical difference between said received AC signal appears as a corresponding number of pulses.
Claim 5
Dependent Claim
23 words
The linearizing system according to claim 1 wherein said comparing means include an integrator for integrating the combined beams from said combining means.
Claim 6
Dependent Claim
123 words
In combination with a ring laser gyroscope having as an output two counter-rotating beams, a linearizing system comprised of: drive means interposed in the optical path of one of said output beams to vary the path length of said beam; combining means for combining the beam from said drive means with the other of said counter-rotating output beams; means for converting said combined beams into a proportional AC signal; and means for receiving said proportional AC signal and for providing a control signal to said drive means which signal is proportional to the non-symmetry of said proportional AC signal, such that said drive means varies the optical path length of said one output beam to cause said proportional AC signal to be symmetrical.
Claim 7
Dependent Claim
123 words
In combination with a ring laser gyroscope having as an output two counter-rotating beams, a linearizing system comprised of: drive means interposed in the optical path of one of said output beams to vary the path length of said beam; combining means for combining the beam from said drive means with the other of said counter-rotating output beams; means for converting said combined beams into a proportional AC signal; and means for receiving said proportional AC signal and for providing a control signal to said drive means which signal is proportional to the non-symmetry of said proportional AC signal, such that said drive means varies the optical path length of said one output beam to cause said proportional AC signal to be symmetrical.
Claim 8
Dependent Claim
200 words
The linearizing system according to claim 5 and further comprising: a clock means for providing a continuous train of pulses; a counter means receiving at one input terminal thereof said provided train of pulses and at another input terminal thereof said proportional electrical signal, said counter means providing an accumulated count of pulses equal to the time difference between alternate half cycles of said proportional electrical signal; another counter means receiving at one terminal thereof said provided train of pulses and at another input terminal thereof said proportional electrical signal, said another counter means providing an accumulated signal proportional to the number of pulses occurring during one cycle of said proportional electrical signal; means for multiplying the provided accumulated pulses from said counter means by a constant value pi /2 and for driving said product by the accumulated signal from said another counter means to provide an output signal; cosecant means for receiving the output signal from said means for multiplying and for forming the cosecant thereof; and accumulator means for accumulating the output of said cosecant means and for providing said accumulated signal as an available output signal proportional to the angle of rotation of said ring laser gyroscope.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-19 | 1976-09-18 | 1977-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-19 | 1980-09-18 | 1981-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-19 | 1984-09-18 | 1985-03-20 | $7700.00 | Window Closed / Lapsed |