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US5552883A Expired / Lapsed US ⏱️ 0.0 years remaining

Noncontact position measurement system using optical sensors

Assignee: The University of Texas System
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Filing: 1994-11-21
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Granted: 1996-09-03
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Expires: 2014-11-21
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Abstract

Abstract Optical and computational components are combined to form a high precision, six degree-of-freedom, single-sided, noncontact position measurement system. Reflective optical targets are provided on a target object whose position is to be sensed. Light beams are directed toward the optical targets, producing reflected beams. Electrical signals are produced indicating the points of intersection of the reflected beams and the position-sensitive detectors. The position sensitive detectors may be lateral-effect photodiodes. The signals are transformed to provide measurements of translation along and rotation around three nonparallel axes which define the space in which the target object moves.

Inventors

  • 👤 Ilene Busch-Vishniac
  • 👤 Alvin B. Buckman
  • 👤 Janardhan K. Pavuluri
  • 👤 Wanjun Wang
  • 👤 Dahong Qian
  • 👤 Vladimir Mancevski

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 13:15
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/26; G01D; G01D5/00; G01D5/26; G01D5/28; G01S; G01S17/00; G01S17/02; G01S17/06; G01S17/42; G01S17/88

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 241 words
A high-precision, non-contact position measuring system for determining the position and motion of a target object with respect to a sensor plane, the measuring system being located substantially entirely in or behind the sensor plane, comprising: a target placed on an exterior surface of the target object, the target comprising at least two planar point reflectors on a substantially non-reflective background; a first light source for producing a first beam of light directed toward the target, the first beam of light being broad enough to illuminate the at least two planar point reflectors, thereby producing a first reflected beam reflected from one of the point reflectors and a second reflected beam reflected from another of the point reflectors; a second light source for producing a second beam of light directed toward the target, the second beam of light being broad enough to illuminate at least one of the at least two planar point reflectors, thereby producing a third reflected beam reflected from said point reflector; a first position sensitive detector positioned in the sensor plane to determine a location of intersection between the first reflected beam and the sensor plane; a second position sensitive detector positioned in the sensor plane to determine a location of intersection between the second reflected beam and the sensor plane; and a third position sensitive detector positioned in the sensor plane to determine a location of intersection between the third reflected beam and the sensor plane.
Claim 2
Dependent Claim 241 words
A high-precision, non-contact position measuring system for determining the position and motion of a target object with respect to a sensor plane, the measuring system being located substantially entirely in or behind the sensor plane, comprising: a target placed on an exterior surface of the target object, the target comprising at least two planar point reflectors on a substantially non-reflective background; a first light source for producing a first beam of light directed toward the target, the first beam of light being broad enough to illuminate the at least two planar point reflectors, thereby producing a first reflected beam reflected from one of the point reflectors and a second reflected beam reflected from another of the point reflectors; a second light source for producing a second beam of light directed toward the target, the second beam of light being broad enough to illuminate at least one of the at least two planar point reflectors, thereby producing a third reflected beam reflected from said point reflector; a first position sensitive detector positioned in the sensor plane to determine a location of intersection between the first reflected beam and the sensor plane; a second position sensitive detector positioned in the sensor plane to determine a location of intersection between the second reflected beam and the sensor plane; and a third position sensitive detector positioned in the sensor plane to determine a location of intersection between the third reflected beam and the sensor plane.
Claim 3
Dependent Claim 44 words
The system of claim 1, further comprising a computer coupled to the first, second and third position sensitive detectors and programmed to determine the position of the target object with respect to the sensor plane based on information provided by the position sensitive detectors.
Claim 4
Dependent Claim 14 words
The system of claim 1, wherein the position sensitive detectors comprise lateral effect photodiodes.
Claim 5
Dependent Claim 13 words
The system of claim 3, wherein the light sources comprise semiconductor light emitters.
Claim 6
Dependent Claim 180 words
A non-contact measurement system for determining the position and motion of a target object with respect to a sensor plane, comprising: a plurality of planar reflective targets positioned on the target object; a first light source for providing a first beam of light that is directed so as to illuminate at least two of said reflective targets, thereby generating at least a first reflected beam of light and a second reflected beam of light; a first detector positioned in the sensor plane to detect the position at which the first reflected beam of light intersects the sensor plane; a second detector positioned in the sensor plane to detect the position at which the second reflected beam of light intersects the sensor plane; a second light source for providing a second beam of light that is directed so as to illuminate at least one of said reflective targets, thereby generating a third reflected beam of light; and a third detector positioned in the sensor plane to detect the position at which the third reflected beam of light intersects the sensor plane.
Claim 7
Dependent Claim 180 words
A non-contact measurement system for determining the position and motion of a target object with respect to a sensor plane, comprising: a plurality of planar reflective targets positioned on the target object; a first light source for providing a first beam of light that is directed so as to illuminate at least two of said reflective targets, thereby generating at least a first reflected beam of light and a second reflected beam of light; a first detector positioned in the sensor plane to detect the position at which the first reflected beam of light intersects the sensor plane; a second detector positioned in the sensor plane to detect the position at which the second reflected beam of light intersects the sensor plane; a second light source for providing a second beam of light that is directed so as to illuminate at least one of said reflective targets, thereby generating a third reflected beam of light; and a third detector positioned in the sensor plane to detect the position at which the third reflected beam of light intersects the sensor plane.
Claim 8
Dependent Claim 43 words
The system of claim 5, further comprising a digital computer coupled to each of the first, second and third detectors, the digital computer being programmed to calculate the position and motion of the target object based on output signals generated by the detectors.
Claim 9
Dependent Claim 33 words
The system of claim 5, wherein the first light source and the second light source both receive light through optical fibers from a master light source and direct that light toward the target.
Claim 10
Dependent Claim 15 words
The system of claim 7, wherein the master light source comprises a light emitting diode.
Claim 11
Independent Claim 111 words
A method for measuring the position of a target object in space without physically contacting the target object, comprising the steps of: providing on a target object a target, the target comprising at least three planar point reflectors on a substantially non-reflective background; projecting a target beam toward the target so as to impinge upon all three point reflectors; reflecting the target beam from the point reflectors to produce a plurality of reflected beams; determining locations at which the reflected beams intersect a sensor plane; and calculating the position of the target object with respect to the sensor plane using the locations at which the reflected beams intersect the sensor plane.
Claim 12
Independent Claim 111 words
A method for measuring the position of a target object in space without physically contacting the target object, comprising the steps of: providing on a target object a target, the target comprising at least three planar point reflectors on a substantially non-reflective background; projecting a target beam toward the target so as to impinge upon all three point reflectors; reflecting the target beam from the point reflectors to produce a plurality of reflected beams; determining locations at which the reflected beams intersect a sensor plane; and calculating the position of the target object with respect to the sensor plane using the locations at which the reflected beams intersect the sensor plane.
Claim 13
Dependent Claim 28 words
The method of claim 9, further comprising providing lateral effect photodiodes in the sensor plane for determining the locations at which the reflected beams intersect the sensor plane.
Claim 14
Independent Claim 105 words
A system for sensing the position of a sensed object in space, the sensed object having a target located on an outer surface thereof, the target comprising at least three planar point reflectors on a substantially non-reflective background, the system comprising: a target beam emitter for projecting a target beam to impinge upon the target to produce at least three reflected beams by reflection from the point reflectors, each reflected beam defining a point of intersection with a sensor plane; and reflected beam position detectors positioned to intercept each reflected beam for determining the points of intersection of the reflected beams with the sensor plane.
Claim 15
Independent Claim 105 words
A system for sensing the position of a sensed object in space, the sensed object having a target located on an outer surface thereof, the target comprising at least three planar point reflectors on a substantially non-reflective background, the system comprising: a target beam emitter for projecting a target beam to impinge upon the target to produce at least three reflected beams by reflection from the point reflectors, each reflected beam defining a point of intersection with a sensor plane; and reflected beam position detectors positioned to intercept each reflected beam for determining the points of intersection of the reflected beams with the sensor plane.
Claim 16
Dependent Claim 45 words
The system of claim 11, further comprising a digital computer coupled to the reflected beam detectors, the computer being programmed to calculate the displacement and rotation of the target object in space using the points of intersection between the reflected beams and the sensor plane.
Claim 17
Dependent Claim 15 words
The system of claim 11, wherein the reflected beam position detectors comprise lateral effect photodiodes.
Claim 18
Independent Claim 108 words
A system for determining the position of a target object in space, comprising: a target comprising a plurality of planar reflectors located on the target object; means for projecting first and second beams of light to impinge upon the target, thereby creating a plurality of reflected beams by reflection of the first and second beams from the planar reflectors; means for determining a points of intersection of the plurality of reflected beams with a sensor plane, said means being positioned in the sensor plane; means for calculating the position of the target object in space using the points of intersection of the reflected beams with the sensor plane.
Claim 19
Independent Claim 108 words
A system for determining the position of a target object in space, comprising: a target comprising a plurality of planar reflectors located on the target object; means for projecting first and second beams of light to impinge upon the target, thereby creating a plurality of reflected beams by reflection of the first and second beams from the planar reflectors; means for determining a points of intersection of the plurality of reflected beams with a sensor plane, said means being positioned in the sensor plane; means for calculating the position of the target object in space using the points of intersection of the reflected beams with the sensor plane.
Claim 20
Dependent Claim 44 words
The system of claim 14, wherein the determining means comprises a position sensitive detector located in the sensor plane, the position sensitive detector having output terminals for providing output signals representing the location at which the reflected beam impinges upon the position sensitive detector.
Claim 21
Dependent Claim 19 words
The system of claim 15, wherein the calculating means comprises a digital computer coupled to the position sensitive detector.
Claim 22
Independent Claim 81 words
A method for determining the position of a target object in space in six degrees of freedom without physically contacting the object, comprising the steps of: providing a plurality of planar reflective surfaces; emitting a plurality of projected light beams to impinge upon the reflective surfaces; reflecting the projected light beams from the reflective surfaces to form reflected beams; determining positions of the reflected beams; and calculating the position of the target object using the determined positions of the reflected beams.
Claim 23
Independent Claim 81 words
A method for determining the position of a target object in space in six degrees of freedom without physically contacting the object, comprising the steps of: providing a plurality of planar reflective surfaces; emitting a plurality of projected light beams to impinge upon the reflective surfaces; reflecting the projected light beams from the reflective surfaces to form reflected beams; determining positions of the reflected beams; and calculating the position of the target object using the determined positions of the reflected beams.
Claim 24
Dependent Claim 29 words
The method of claim 17, further comprising providing lateral effect photodiodes located in a sensor plane, and employing said lateral effect photodiodes for determining positions of the reflected beams.

References Cited (Backward Citations)

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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) 1999-09-03 2000-03-04 2000-09-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-09-03 2004-03-04 2004-09-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-09-03 2008-03-04 2008-09-03 $7700.00 Window Closed / Lapsed

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