US4443103A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Retro-reflective electro-optical angle measuring system
Assignee: Boeing Co
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Filing: 1983-05-31
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Granted: 1984-04-17
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Expires: 2003-05-31
Abstract
Abstract A scanning angle tracker which includes a laser beam and a beamsplitter for developing two beams which intersect on a scanning mirror. The scanning mirror sweeps the two beams across a retro-reflective tape on the object. Return signals are generated for processing to provide the desired angular information.
Inventors
- 👤 Joachim C. Erdmann
- 👤 Robert I. Gellert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:35
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/26
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A retro-reflective electro-optical angle measuring system comprising in combination: transmitting means for generating a first laser beam; a beamsplitter for developing two angularly divergent sub-beams from said first laser beam; a mirror system; individual sub-beam associated photomultipliers; a vibrating mirror disposed in the path of said sub-beams for sweeping said sub-beams across a retro-reflective tape and for re-directing the retro-reflected sub-beams back through said mirror system and upon said respective individual sub-beam associated photomultipliers, said photomultipliers responsive to said sub-beams for providing photomultiplier pulses when said sub-beams cross said retro-reflective tape; and, receiving means responsive to the time interval between said photomultiplier pulses for angle measurement between said retro-reflective tape and a reference plane formed by said sweeping sub-beams, the sign of the angle dependent upon the sequence of said sub-beams crossing said retro-reflective tape.
Claim 2
Dependent Claim
135 words
A retro-reflective electro-optical angle measuring system comprising in combination: transmitting means for generating a first laser beam; a beamsplitter for developing two angularly divergent sub-beams from said first laser beam; a mirror system; individual sub-beam associated photomultipliers; a vibrating mirror disposed in the path of said sub-beams for sweeping said sub-beams across a retro-reflective tape and for re-directing the retro-reflected sub-beams back through said mirror system and upon said respective individual sub-beam associated photomultipliers, said photomultipliers responsive to said sub-beams for providing photomultiplier pulses when said sub-beams cross said retro-reflective tape; and, receiving means responsive to the time interval between said photomultiplier pulses for angle measurement between said retro-reflective tape and a reference plane formed by said sweeping sub-beams, the sign of the angle dependent upon the sequence of said sub-beams crossing said retro-reflective tape.
Claim 3
Dependent Claim
110 words
In combination in a system including a target and a follower, said target having a retro-reflective film, said follower including means for providing two optical beams, and said follower mounted on a platform for rotation and alignment with respect to said retro-reflective film: means for providing a measure for the angle between said retro-reflective film and reference plane of the platform of said follower by derivation from the time difference between light pulses returning after retro-reflections from said retro-reflective film disposed on said target; and, means responsive to said time difference between light pulses for controlling rotation of said follower for aligning said follower platform parallel to said retro-reflective film.
Claim 4
Dependent Claim
110 words
In combination in a system including a target and a follower, said target having a retro-reflective film, said follower including means for providing two optical beams, and said follower mounted on a platform for rotation and alignment with respect to said retro-reflective film: means for providing a measure for the angle between said retro-reflective film and reference plane of the platform of said follower by derivation from the time difference between light pulses returning after retro-reflections from said retro-reflective film disposed on said target; and, means responsive to said time difference between light pulses for controlling rotation of said follower for aligning said follower platform parallel to said retro-reflective film.
Claim 5
Dependent Claim
18 words
The invention according to claim 2 wherein means for controlling rotation of said follower is rotation rate programmable.
Claim 6
Dependent Claim
14 words
The invention according to claim 2 wherein said film is retro-reflective in any plane.
Claim 7
Independent Claim
140 words
A method for measuring the orientation angle of an object relative to a reference plane comprising the steps of: disposing retro-reflective means on said object; providing a pair of laser beams intersecting to form a reference plane; periodically sweeping jointly said pair of laser beams normal to said reference plane across said retro-reflective means thereby providing flashes of reflected light when light spots are incident upon said retro-reflective means in a simultaneous manner whenever said orientation angle is zero valued and at different times other than in a simultaneous manner whenever said orientation angle is not zero valued; and, recording the time difference ΔT of the light flashes in a pair of receiver channels corresponding respectively to said pair of laser beams, said time difference ΔT being a function of the angle between said retro-reflective means and said reference plane.
Claim 8
Independent Claim
140 words
A method for measuring the orientation angle of an object relative to a reference plane comprising the steps of: disposing retro-reflective means on said object; providing a pair of laser beams intersecting to form a reference plane; periodically sweeping jointly said pair of laser beams normal to said reference plane across said retro-reflective means thereby providing flashes of reflected light when light spots are incident upon said retro-reflective means in a simultaneous manner whenever said orientation angle is zero valued and at different times other than in a simultaneous manner whenever said orientation angle is not zero valued; and, recording the time difference ΔT of the light flashes in a pair of receiver channels corresponding respectively to said pair of laser beams, said time difference ΔT being a function of the angle between said retro-reflective means and said reference plane.
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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) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |