US3757093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self leveling system using periodic perturbations
Assignee: United States Department of the Navy
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Filing: 1972-09-22
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Granted: 1973-09-04
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Expires: 1992-09-22
Abstract
Abstract A system for leveling a stable or strapped down missile guidance platform on a moving ship having accelerometers and gyroscopes. Periodic signals perturbate the system allowing leveling of the platform which is superimposed on a control function to cancel ship motion.
Inventors
- 👤 W Licata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:09
CPC Classifications
G; G01; G01C; G01C25/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
145 words
A self-leveling system for a platform having accelerometers comprising: a first oscillator operating at a frequency f1; a second oscillator operating at a frequency f2; a first gyroscope motor coupled to said first oscillator; a second gyroscope motor coupled to said second oscillator; said first and second motors operating on said platform to produce a function to be minimized; a first filter for bandpassing signals containing said frequency f1 from said function; first means coupled to said first filter for comparing said first oscillator signal with said f1 bandpassed signals; said first means supplying an input signal to said first gyroscope motor; a second filter for bandpassing signals containing said frequency f2 from said function; second means coupled to said second filter for comparing said second oscillator signal with said f2 bandpassed signals; said second means supplying an input sigNal to said second gyroscope motor.
Claim 2
Dependent Claim
145 words
A self-leveling system for a platform having accelerometers comprising: a first oscillator operating at a frequency f1; a second oscillator operating at a frequency f2; a first gyroscope motor coupled to said first oscillator; a second gyroscope motor coupled to said second oscillator; said first and second motors operating on said platform to produce a function to be minimized; a first filter for bandpassing signals containing said frequency f1 from said function; first means coupled to said first filter for comparing said first oscillator signal with said f1 bandpassed signals; said first means supplying an input signal to said first gyroscope motor; a second filter for bandpassing signals containing said frequency f2 from said function; second means coupled to said second filter for comparing said second oscillator signal with said f2 bandpassed signals; said second means supplying an input sigNal to said second gyroscope motor.
Claim 3
Dependent Claim
38 words
A self-leveling system as recited in claim 1 wherein said function comprises Ax2 + Ay2 + (Az -g)2, where Ax, Ay and Az are the outputs of said platform accelerometers and g is a voltage representative of gravity.
Claim 4
Dependent Claim
40 words
A self-leveling system as recited in claim 2 wherein: said first gyroscope operates on the Euler pitch angle and said second gyroscope operates on the Euler yaw angles; and wherein said function includes terms containing said pitch and yaw angles.
Claim 5
Dependent Claim
26 words
A self-leveling system as recited in claim 3 wherein said first and second means comprise a phase sensitive detector including a multiplier and low pass filter.
Claim 6
Dependent Claim
35 words
A self-leveling system as recited in claim 4 further including a phase shifter coupled between said first oscillator and said first means; and a phase shifter coupled between said second oscillator and said second means.
Claim 7
Dependent Claim
33 words
A self-leveling system as recited in claim 5 wherein the outputs of said phase sensitive detectors are d.c. voltages and said frequency f1 is 1 Hz and said frequency f2 is 5 Hz.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |