US5047653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device on board a moving vehicle to obtain signals representative of the relative speed of the vehicle with respect to an ambient fluid
Assignee: Thales SA
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Filing: 1990-06-25
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Granted: 1991-09-10
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Expires: 2010-06-25
Abstract
Abstract A device uses fringe laser diode anemometers which, from the beams coming from one or more laser diodes, form measuring volumes having interference fringes. The component of the relative speed of an aircraft in a direction perpendicular to the plane of these fringes is deduced from the modulation of light reflected by particles moving through the measuring volume to cause modulation of the signal of the photodetector of each anemometer during their passage in the measuring volume of this anemometer. By joining two anemometers with the measuring volumes whose planes of the associated fringes are, for example, orthogonal, it is possible to determine two components of the relative speed vector and determine, for example, this relative speed in the longitudinal vertical plane of the aircraft, and to deduce from it the angle of incidence of the aircraft.
Inventors
- 👤 James Garcia
- 👤 Gerard Beigbeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:03
CPC Classifications
G; G01; G01P; G01P5/00; G01P5/26
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
170 words
A device for obtaining signals representative of a relative speed of a vehicle with respect to an ambient fluid comprising: at least one fringe anemometer, positioned on board the vehicle, and having: a radiant energy emitting source for emitting a radiant energy beam, measuring volume forming means for forming the radiant energy beam into a measuring volume having at least an interference fringe and a measuring axis, a photodetector for receiving light reflected from the measuring volume and for generating output signals representative thereof, and an optical filter having a bandpass substantially at an emission frequency of the radiant energy beam of the radiant energy emitting source, the optical filter being position along an optical path extending between the measuring volume and the photodetector; and orienting means for orienting the measuring axis of the measuring volume of the at least one laser anemometer in at least two different directions so that the photodetector generates signals representative of light reflected from the measuring volume for the at least two different directions.
Claim 2
Independent Claim
170 words
A device for obtaining signals representative of a relative speed of a vehicle with respect to an ambient fluid comprising: at least one fringe anemometer, positioned on board the vehicle, and having: a radiant energy emitting source for emitting a radiant energy beam, measuring volume forming means for forming the radiant energy beam into a measuring volume having at least an interference fringe and a measuring axis, a photodetector for receiving light reflected from the measuring volume and for generating output signals representative thereof, and an optical filter having a bandpass substantially at an emission frequency of the radiant energy beam of the radiant energy emitting source, the optical filter being position along an optical path extending between the measuring volume and the photodetector; and orienting means for orienting the measuring axis of the measuring volume of the at least one laser anemometer in at least two different directions so that the photodetector generates signals representative of light reflected from the measuring volume for the at least two different directions.
Claim 3
Dependent Claim
15 words
A device according to claim 1, wherein the radiant energy source is a laser diode.
Claim 4
Dependent Claim
59 words
A device according to claim 1, wherein the measuring volume forming means comprises a beam separator for splitting the radiant energy beam into at least two beams which convert toward the measuring volume and wherein the orienting means comprises a rotary support for rotating the beam separator about an axis extending between the beam separator and the measuring axis.
Claim 5
Dependent Claim
19 words
A device according to claim 3, wherein the rotary support drives the beam separator in a continuous rotational movement.
Claim 6
Dependent Claim
18 words
A device according to claim 3, wherein the rotary support drives the beam separator in an oscillating movement.
Claim 7
Dependent Claim
15 words
A device according to claim 5, wherein the oscillating movement is of a pendular type.
Claim 8
Dependent Claim
26 words
A device according to claim 5, wherein oscillating movement occurs with abrupt passage between two end positions with stops of predetermined duration at each end position.
Claim 9
Dependent Claim
22 words
A device according to claim 1, further comprising an iris positioned at the optical axis between the measuring volume and the photodetector.
Claim 10
Dependent Claim
47 words
A device according to claim 1, wherein the at least one fringe anemometer forms a double anemometer having a common diode laser as the radiant energy source, a beam separator as the measuring volume forming means, the beam separator forming four output beams, and two separate photodetectors.
Claim 11
Independent Claim
147 words
A device for obtaining signals representative of a relative speed of a vehicle with respect to an ambient fluid comprising: n fringe anemometers positioned on board the vehicle, wherein n is a positive integer, each anemometer having: a radiant energy emitting source for emitting a radiant energy beam, measuring volume forming means for forming the radiant energy beam into a measuring volume having an interference fringe and a measuring axis, a photodetector for receiving light reflected from the measuring volume and for generating output signals representative thereof, and an optical filter having a bandpass substantially at an emission frequency of the radiant energy beam of the radiant energy emitting source, the optical filter being position along an optical path extending between the measuring volume and the photodetector, wherein the measuring axes of the measuring volumes of the n fringe anemometers extend in at least two separate directions.
Claim 12
Independent Claim
147 words
A device for obtaining signals representative of a relative speed of a vehicle with respect to an ambient fluid comprising: n fringe anemometers positioned on board the vehicle, wherein n is a positive integer, each anemometer having: a radiant energy emitting source for emitting a radiant energy beam, measuring volume forming means for forming the radiant energy beam into a measuring volume having an interference fringe and a measuring axis, a photodetector for receiving light reflected from the measuring volume and for generating output signals representative thereof, and an optical filter having a bandpass substantially at an emission frequency of the radiant energy beam of the radiant energy emitting source, the optical filter being position along an optical path extending between the measuring volume and the photodetector, wherein the measuring axes of the measuring volumes of the n fringe anemometers extend in at least two separate directions.
Claim 13
Dependent Claim
15 words
A device according to claim 10, wherein the radiant energy source is a laser diode.
Claim 14
Dependent Claim
55 words
A device according to claim 10, wherein n is equal to two, wherein two respective measuring volumes are formed by the n fringe anemometers, the two respective measuring volumes being juxtaposed to one another, and wherein the measuring axes of the two respective measuring volumes are oriented at an angle with respect to one another.
Claim 15
Dependent Claim
42 words
A device according to claim 10, wherein the measuring volume forming means comprises a beam separator and wherein the orienting means comprises a rotary support for rotating the beam separator about an axis extending between the measuring volume and the beam separator.
Claim 16
Dependent Claim
15 words
A device according to claim 13, wherein the rotary support continuously rotates the beam separator.
Claim 17
Dependent Claim
17 words
A device according to claim 13, wherein therrotary support drives the beam separator in an oscillating movement.
Claim 18
Dependent Claim
15 words
A device according to claim 15, wherein the oscillating movement is of a pendular type.
Claim 19
Dependent Claim
26 words
A device according to claim 15, wherein oscillating movement occurs with abrupt passage between two end positions with stops of predetermined duration at each end position.
Claim 20
Dependent Claim
29 words
A device according to claim 10, wherein each of the n fringe anemometers further includes an iris positioned at the optical axis between the measuring volume and the photodetector.
Claim 21
Dependent Claim
55 words
A device according to claim 10, wherein n is at least equal to two and wherein two of the n anemometer form a double anemometer having a common diode laser as the radiant energy source, a beam separator as the measuring volume forming means, the beam separator forming four output beams, and two separate photodetectors.
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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) | 1994-09-09 | 1995-03-11 | 1995-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-09 | 1999-03-11 | 1999-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-09 | 2003-03-11 | 2003-09-10 | $7700.00 | Window Closed / Lapsed |