US5486821A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Artificial horizon altitude warning system
Assignee: United States Department of the Navy
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Filing: 1994-05-26
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Granted: 1996-01-23
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Expires: 2014-05-26
Abstract
Abstract An artificial horizon altitude warning system is provided for helping to prevent a controlled flight of an aircraft into the ground. The artificial horizon altitude warning system comprises an altimeter for gathering altitude information about the aircraft and generating an altitude signal; a laser assembly for producing a light in a cockpit of the aircraft; and a controller for receiving the altitude signal and for positioning the light in the cockpit to form an artificial line based on the altitude signal, the artificial line being positioned so as to be disposed along tin arcuate length corresponding to the location of an actual horizon as viewed by a pilot of the aircraft.
Inventors
- 👤 David E. Stevens
- 👤 Leonard A. Temme
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:17
CPC Classifications
G; G01; G01C; G01C15/00; G01C15/14; G01C23/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
226 words
An artificial horizon warning system for an aircraft containing an altitude measuring and or ground proximity devices which provides a warning when a controlled flight of the aircraft will result in a collision with the ground, said system comprising: means for gathering altitude information about said aircraft from said altitude and proximity measuring device and generating an altitude signal; laser light generating means for producing at least one ray of laser light in a cockpit of said aircraft; and control means for receiving said altitude signal and for positioning one ray of said light in said cockpit to form an artificial line based on said altitude signal, said artificial line being positioned so as to be disposed along an arcuate length corresponding to the location of an actual horizon as viewed by a pilot of said aircraft wherein said artificial line is disposed at the intersection of said one ray of said light and said cockpit, said one ray of light being defined by a visual horizon, angle, said visual horizon angle being defined by: ##EQU3## where, x is said visual horizon angle, R is the radius of the earth, and A is the altitude of said aircraft, said visual horizon angle being measured from a line extending from a pilot's eye to the horizon and from said pilot's eye to the center of the earth.
Claim 2
Dependent Claim
226 words
An artificial horizon warning system for an aircraft containing an altitude measuring and or ground proximity devices which provides a warning when a controlled flight of the aircraft will result in a collision with the ground, said system comprising: means for gathering altitude information about said aircraft from said altitude and proximity measuring device and generating an altitude signal; laser light generating means for producing at least one ray of laser light in a cockpit of said aircraft; and control means for receiving said altitude signal and for positioning one ray of said light in said cockpit to form an artificial line based on said altitude signal, said artificial line being positioned so as to be disposed along an arcuate length corresponding to the location of an actual horizon as viewed by a pilot of said aircraft wherein said artificial line is disposed at the intersection of said one ray of said light and said cockpit, said one ray of light being defined by a visual horizon, angle, said visual horizon angle being defined by: ##EQU3## where, x is said visual horizon angle, R is the radius of the earth, and A is the altitude of said aircraft, said visual horizon angle being measured from a line extending from a pilot's eye to the horizon and from said pilot's eye to the center of the earth.
Claim 3
Dependent Claim
24 words
The warning system recited in claim 1, further comprising means for determining descent rate and sending a descent rate signal to said control means.
Claim 4
Dependent Claim
43 words
The warning system recited in claim 2 wherein said control means receives said descent rate signal in combination with said altitude information, said control means for rapidly moving said artificial line above said actual horizon when said descent rate exceeds a predetermined value.
Claim 5
Dependent Claim
19 words
The warning system recited in claim 1 wherein said artificial line is projected on a canopy of said aircraft.
Claim 6
Dependent Claim
23 words
The warning system recited in claims 4 wherein said canopy is coated with a film that reflects only the projected artificial horizon display.
Claim 7
Dependent Claim
38 words
The warning system recited in claim 1, further comprising means for gathering attitude information about said aircraft and means for transmitting said attitude information to the control means, said attitude information comprising at least pitch and roll information.
Claim 8
Dependent Claim
70 words
The warning system recited in claim 6 wherein said control means receives said altitude signal and attitude information and positions said one ray of light in said cockpit to form said artificial line based on said altitude and attitude information, said artificial line being positioned so as to be disposed along said arcuate length corresponding to the location of said actual horizon as viewed by said pilot of said aircraft.
Claim 9
Dependent Claim
29 words
The warning system recited in claim 1 wherein said control means rapidly moves said artificial line above said actual horizon when said altitude signal falls below a predetermined value.
Claim 10
Dependent Claim
205 words
An artificial horizon warning system for an aircraft which provides a warning when a controlled flight of the aircraft will result in a collision with the ground, said system comprising: means for gathering altitude information about said aircraft; means for gathering attitude information about said aircraft, said attitude information comprising at least pitch and roll information; light generating means for producing at least one ray of light in a cockpit of said aircraft; and control means for receiving said altitude and attitude information and for positioning said light in said cockpit to form an artificial line based on said altitude and attitude information, said artificial line being positioned so as to be disposed along an arcuate length in said cockpit, wherein said artificial line is disposed at the intersection of a ray of said light and said cockpit, said ray being defined by a visual horizon angle, said visual horizon angle being defined by: ##EQU4## where, x is said visual horizon angle, R is the radius of the earth, and A is the altitude of said aircraft, said visual horizon angle being measured from a line extending from a pilot's eye to the horizon and from said pilot's eye to the center of the earth.
Claim 11
Dependent Claim
205 words
An artificial horizon warning system for an aircraft which provides a warning when a controlled flight of the aircraft will result in a collision with the ground, said system comprising: means for gathering altitude information about said aircraft; means for gathering attitude information about said aircraft, said attitude information comprising at least pitch and roll information; light generating means for producing at least one ray of light in a cockpit of said aircraft; and control means for receiving said altitude and attitude information and for positioning said light in said cockpit to form an artificial line based on said altitude and attitude information, said artificial line being positioned so as to be disposed along an arcuate length in said cockpit, wherein said artificial line is disposed at the intersection of a ray of said light and said cockpit, said ray being defined by a visual horizon angle, said visual horizon angle being defined by: ##EQU4## where, x is said visual horizon angle, R is the radius of the earth, and A is the altitude of said aircraft, said visual horizon angle being measured from a line extending from a pilot's eye to the horizon and from said pilot's eye to the center of the earth.
Claim 12
Dependent Claim
20 words
The warning system recited in claim 9, further comprising means for determining descent rate and outputting a descent rate signal.
Claim 13
Dependent Claim
43 words
The warning system recited in claim 10 wherein said control means receives said descent rate signal in combination with said altitude information, said control means for rapidly moving said artificial line above said actual horizon when said descent rate exceeds a predetermined value.
Claim 14
Dependent Claim
19 words
The warning system recited in claim 9 wherein said artificial line is projected on a canopy of said aircraft.
Claim 15
Dependent Claim
23 words
The warning system recited in claim 12 wherein said canopy is coated with a film that reflects only the projected artificial horizon display.
Claim 16
Dependent Claim
29 words
The warning system recited in claim 9 wherein said control means rapidly moves said artificial line above said actual horizon when said altitude signal falls below a predetermined value.
Claim 17
Independent Claim
185 words
A method for providing a warning when a controlled flight of an aircraft will result in a collision with the ground, said method comprising the steps of: (a) generating a signal indicative of an altitude of said aircraft; (b) projecting a ray of laser light from a light source on a cockpit so that said light source forms an artificial line based on said altitude signal, said artificial line being positioned so as to be disposed along an arcuate length corresponding to the location of an actual horizon as viewed by a pilot of said aircraft; and (c) dynamically adjusting said artificial line so as to be disposed at the intersection of a ray and said cockpit, said ray being defined by a visual horizon angle, said visual horizon angle being defined by: ##EQU5## where, x is said visual horizon angle, R is the radius of the earth, and A is the altitude of said aircraft, said visual horizon angle being measured from a line extending from a pilot's eye to the actual horizon and from said pilot's eye to the center of the earth.
Claim 18
Independent Claim
185 words
A method for providing a warning when a controlled flight of an aircraft will result in a collision with the ground, said method comprising the steps of: (a) generating a signal indicative of an altitude of said aircraft; (b) projecting a ray of laser light from a light source on a cockpit so that said light source forms an artificial line based on said altitude signal, said artificial line being positioned so as to be disposed along an arcuate length corresponding to the location of an actual horizon as viewed by a pilot of said aircraft; and (c) dynamically adjusting said artificial line so as to be disposed at the intersection of a ray and said cockpit, said ray being defined by a visual horizon angle, said visual horizon angle being defined by: ##EQU5## where, x is said visual horizon angle, R is the radius of the earth, and A is the altitude of said aircraft, said visual horizon angle being measured from a line extending from a pilot's eye to the actual horizon and from said pilot's eye to the center of the earth.
Claim 19
Dependent Claim
29 words
The method recited in claim 15, further comprising the step of: rapidly moving said artificial line above said actual horizon when said altitude signal falls below a predetermined value.
Claim 20
Dependent Claim
41 words
The method recited in claim 15, further comprising the steps of: (a) generating a signal indicative of descent rate of said aircraft; and (b) rapidly moving said artificial line above said actual horizon when said descent rate exceeds a predetermined value.
Claim 21
Dependent Claim
69 words
The method recited in claim 15, further comprising the steps of: (a) generating a second signal indicative of the attitude of said aircraft; and (b) forming said artificial line based on both said altitude signal and said attitude signal, said artificial line being positioned so as to be disposed along said arcuate length corresponding to the location of said actual horizon as viewed by said pilot of said aircraft.
References Cited (Backward Citations)
US4397555A
Cited
US4616226A
Cited
US4743903A
Cited
US5075685A
Cited
US5220322A
Cited
US5187478A
Cited
US5038141A
Cited
US5072218A
Cited
US4936142A
Cited
US5134394A
Cited
US5334995A
Cited
US5218355A
Cited
US5321415A
Cited
US5214425A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-22 | 1999-07-24 | 2000-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-22 | 2003-07-24 | 2004-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-22 | 2007-07-24 | 2008-01-23 | $7700.00 | Window Closed / Lapsed |