Patent US4680866A successfully refreshed from Google Patents.
US4680866A
Expired / Lapsed
US
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Magnetic flux detector correction system
Assignee: Honeywell Inc
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Filing: 1985-12-19
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Granted: 1987-07-21
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Expires: 2005-12-19
Abstract
Abstract An aircraft heading correction system utilizing the horizontal field strength of the earth's magnetic field to determine the tangent of the dip angle generally associated with a given field strength. The tangent of the dip angle is then used to generate a signal which corrects the flux valve heading during accelerated flight.
Inventors
- 👤 James S. Johnson
- 👤 Gene A. Albrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:23
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/38
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
197 words
An aircraft heading correction system of the type utilizing a magnetic flux detector to provide a signal as a function of magnetic heading of said aircraft, said correction system comprising: a first means, configured to accept: (a) a signal representative of north, east and down acceleration components of said aircraft, (b) said signal as a function of magnetic heading of said aircraft, for providing a signal representative of horizontal field strength, a second means, configured to accept said signal representative of horizontal field strength, for providing said signal representative of horizontal field strength and a signal representative of the tangent of a dip angle, a third means, configured to accept said signal as a function of magnetic heading of said aircraft, for providing a magnetic heading signal, a fourth means, configured to accept: (a) said signal representative of horizontal field strength, (b) said signal representative of the tangent of a dip angle, (c) said signal representative of north, east and down acceleration components of said aircraft, for providing a magnetic heading correction signal, and a fifth means, configured to accept said magnetic heading correction signal and said magnetic heading signal for providing a corrected magnetic heading signal.
Claim 2
Dependent Claim
197 words
An aircraft heading correction system of the type utilizing a magnetic flux detector to provide a signal as a function of magnetic heading of said aircraft, said correction system comprising: a first means, configured to accept: (a) a signal representative of north, east and down acceleration components of said aircraft, (b) said signal as a function of magnetic heading of said aircraft, for providing a signal representative of horizontal field strength, a second means, configured to accept said signal representative of horizontal field strength, for providing said signal representative of horizontal field strength and a signal representative of the tangent of a dip angle, a third means, configured to accept said signal as a function of magnetic heading of said aircraft, for providing a magnetic heading signal, a fourth means, configured to accept: (a) said signal representative of horizontal field strength, (b) said signal representative of the tangent of a dip angle, (c) said signal representative of north, east and down acceleration components of said aircraft, for providing a magnetic heading correction signal, and a fifth means, configured to accept said magnetic heading correction signal and said magnetic heading signal for providing a corrected magnetic heading signal.
Claim 3
Dependent Claim
46 words
An aircraft heading correction system according to claim 1 wherein said signal as a function of magnetic heading of said aircraft comprises a first and second signal having the relationship: said first signal=X.sub.1 =horizontal field strength×sine (magnetic heading) said second signal=X.sub.2 =horizontal field strength×cosine (magnetic heading).
Claim 4
Dependent Claim
22 words
A system according to claim 2 wherein said signal representative of horizontal field strength has the form horizontal field strength=[X.sub.1.sup.2 +X.sub.2.sup.2 ].sup.1/2.
Claim 5
Dependent Claim
25 words
A system according to claim 2 wherein said third means provides a magnetic heading sigal having the form tan -1 [X 1 /X 2 ].
Claim 6
Dependent Claim
47 words
A system according to claim 3 wherein said signal representative of the tangent of a dip angle is of the form tangent of Dip=A.sub.0 +A.sub.1 ×HFS+A.sub.2 ×HFS.sup.2 +A.sub.3 ×HFS.sup.3 where A 0 , A 1 , A 2 and A 3 are predetermined constants HFS=horizontal field strength.
Claim 7
Dependent Claim
56 words
A system according to claim 5 wherein said magnetic heading correction signal is of the form: ##EQU1## where east component=[tan (dip angle)×sin A EM /A DOWN )], north component=[tan (dip angle×sin (A NM /A DOWN )]+cos (A NM /A DOWN )], A EM =aircraft east acceleration, A NM =aircraft north acceleration, A DOWN =aircraft down acceleration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-20 | 1991-01-19 | 1991-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-20 | 1995-01-19 | 1995-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-20 | 1999-01-19 | 1999-07-21 | $7700.00 | Window Closed / Lapsed |