Patent US4470835A successfully refreshed from Google Patents.
Patent US3568960A successfully refreshed from Google Patents.
US3568960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter flight control system
Assignee: CARL D GRIFFITH
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Filing: 1969-04-28
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Granted: 1971-03-09
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Expires: 1989-04-28
Abstract
Abstract This invention relates to a heading control system for flight control of a helicopter of the single rotor type. Nonsimilar, redundant signals from a directional gyro are separately processed in a nonlinear manner so as to produce a more accurate and rapid trim response. One of the redundant signals, responsive to heading error, is processed and fed to a nonlinear gain element. The other of the redundant signals, responsive to heading rate of change, is processed and fed to a deadzone, nonlinear gain element. The redundant signals are then combined and subsequently fed to the trim servo.
Inventors
- 👤 Carl D Griffith
- 👤 Victor H Levi
- 👤 John S Mcbrayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:12
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/0055; G05D1/0077
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
77 words
A method of controlling the heading of an aircraft comprising the steps of: processing a heading error signal through one path to control a trim servo; and processing a heading rate signal through another path in such a manner as to control said trim servo when said heading rate signal exceeds predetermined limits thereby controlling the heading of an aircraft when one path of said processed signal fails as well as when said processed signals properly function.
Claim 2
Independent Claim
77 words
A method of controlling the heading of an aircraft comprising the steps of: processing a heading error signal through one path to control a trim servo; and processing a heading rate signal through another path in such a manner as to control said trim servo when said heading rate signal exceeds predetermined limits thereby controlling the heading of an aircraft when one path of said processed signal fails as well as when said processed signals properly function.
Claim 3
Dependent Claim
32 words
The method of controlling the heading of an aircraft according to claim 1 and further including the step of: combining said processed signals before they are employed to control said trim servo.
Claim 4
Dependent Claim
105 words
An aircraft flight control system comprising: a first means for detecting variation in heading of an aircraft from a predetermined reference heading; a trim servo; a first signal processing means for applying said variation in heading to said trim servo; a second means for detecting the rate of variation in heading of said aircraft from said predetermined reference heading, and; a second signal processing means for applying said rate of variation to said trim servo thereby controlling the heading of the aircraft about a predetermined reference heading when one of said signal processing means fails as well as when said signal processing means properly function.
Claim 5
Dependent Claim
105 words
An aircraft flight control system comprising: a first means for detecting variation in heading of an aircraft from a predetermined reference heading; a trim servo; a first signal processing means for applying said variation in heading to said trim servo; a second means for detecting the rate of variation in heading of said aircraft from said predetermined reference heading, and; a second signal processing means for applying said rate of variation to said trim servo thereby controlling the heading of the aircraft about a predetermined reference heading when one of said signal processing means fails as well as when said signal processing means properly function.
Claim 6
Dependent Claim
51 words
An aircraft flight control system according to claim 3, and further comprising: means for combining said first means for detecting heading variations and said second means for detecting heading rate variations in such a manner that said detected heading variations and said rate variations jointly effect control of said trim servo.
Claim 7
Dependent Claim
31 words
An aircraft flight control system according to claim 4, and further comprising that said second signal processing means is effective only when said heading variation is out of a predetermined range.
Claim 8
Dependent Claim
19 words
An aircraft flight control system according to claim 3 wherein said first signal processing means contains a nonlinear amplifier.
Claim 9
Dependent Claim
19 words
An aircraft flight control system according to claim 3 wherein said second signal processing means contains a deadspot amplifier.
Claim 10
Dependent Claim
29 words
An aircraft flight control system according to claim 3 wherein said first signal processing means contains a nonlinear amplifier and said second signal processing means contains a deadspot amplifier.
Claim 11
Dependent Claim
29 words
An aircraft flight control system according to claim 5 wherein said first signal processing means contains a nonlinear amplifier and said second signal processing means contains a deadspot amplifier.
Claim 12
Dependent Claim
30 words
An aircraft flight control system according to claim 9 and further comprising a series servo with a separate output connected to said first signal processing means before said nonlinear amplifier.
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) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |