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US4991509A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical proximity detector

Assignee: United States Department of the Navy
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Filing: 1983-06-24
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Granted: 1991-02-12
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Expires: 2003-06-24
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Abstract

Abstract Method and apparatus for optically detecting an object within close proxiy to a structure surface, e.g., the nose of a torpedo or claw of a robotic arm, and generating a responsive control or command signal. A cone of light is emitted from the structure surface to illuminate any object coming within its field. Light reflected from that object to a receiver is processed to generate a responsive first electrical signal. This first signal is further processed to generate a second signal, control or a command signal, only after the first signal has decreased to around 30% of its peak level indicating that the object has closed to within a predetermined distance to the structure surface.

Inventors

  • 👤 Paul J. Smith

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 23:02
CPC Classifications
F; F42; F42C; F42C13/00; F42C13/02; F42C13/023; G; G01; G01S; G01S17/00; G01S17/02; G01S17/04

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 209 words
A proximity detector for detecting an object at a predetermined distance in front of a structure surface comprising: a pair of optical fibers each terminating in laterally spaced-apart first ends facing in the same optical direction and having cones of acceptance which partially overlap in front of the structure surface to define a common volume; one of the pair of optical fibers coupled with a light source at its other end to emit that light from its one end to illuminate objects coming within its cone of acceptance; the other of the pair of optical fibers adapted to receive in its first end light reflected from illuminated objects coming within the common volume of the cones of acceptance and transport that light to its other end; photodetector means receiving reflected light emitted from the optical fiber other end; said photodetector means converting that light to a first electrical signal; and means processing the first electrical signal to generate a second signal only after the first electrical signal has decreased to around 30% of its peak level; whereby the second signal defines a control signal only after an object has come in closer proximity to the structure surface than where reflected light from the common volume was at its maximum.
Claim 2
Dependent Claim 209 words
A proximity detector for detecting an object at a predetermined distance in front of a structure surface comprising: a pair of optical fibers each terminating in laterally spaced-apart first ends facing in the same optical direction and having cones of acceptance which partially overlap in front of the structure surface to define a common volume; one of the pair of optical fibers coupled with a light source at its other end to emit that light from its one end to illuminate objects coming within its cone of acceptance; the other of the pair of optical fibers adapted to receive in its first end light reflected from illuminated objects coming within the common volume of the cones of acceptance and transport that light to its other end; photodetector means receiving reflected light emitted from the optical fiber other end; said photodetector means converting that light to a first electrical signal; and means processing the first electrical signal to generate a second signal only after the first electrical signal has decreased to around 30% of its peak level; whereby the second signal defines a control signal only after an object has come in closer proximity to the structure surface than where reflected light from the common volume was at its maximum.
Claim 3
Dependent Claim 20 words
The invention according to claim 1 further defined by the structure surface being the surface of a robotic grasping claw.
Claim 4
Dependent Claim 19 words
The invention according to claim 1 further defined by the structure surface being the nose surface of a torpedo.
Claim 5
Dependent Claim 25 words
The invention according to claim 2 further defined by the optical fiber first ends terminating substantially adjacent the structure surface of the robotic grasping claw.
Claim 6
Dependent Claim 28 words
The invention according to claim 3 further defined by the optical fiber first ends terminating substantially adjacent the structure surface defining the forward nose surface of a torpedo.
Claim 7
Dependent Claim 239 words
A proximity detector for use on a torpedo for detecting the surface of an underwater object being approached by the torpedo nose, comprising: at least one pair of optical fibers having first ends terminating adjacent the nose surface and facing optically forward thereof; said optical fiber first ends spaced apart a selected lateral distance so that their cones of acceptance mutually overlap commencing a short distance in front of the nose surface to define a common volume; one of the optical fibers coupled with a light source for emitting light from its first end for illuminating the surface of an underwater object ahead of the torpedo in its cone of acceptance; the other of the optical fibers adapted to receive in its cone of acceptance light reflected from the surface of the underwater object coming within the common volume of the cones of acceptance and transport that light to its other end; means detecting the transported reflected light at the fiber end and converting it to a responsive first electrical signal; and, means processing the first electrical signal and providing a second electrical signal only after the first electrical signal has decreased to approximately 30% of its peak level; whereby the second electrical signal defines a signal for firing a warhead aboard the torpedo only after the approached object surface has become closer to the torpedo nose surface than in the common volume where maximum light reflection is received.
Claim 8
Dependent Claim 239 words
A proximity detector for use on a torpedo for detecting the surface of an underwater object being approached by the torpedo nose, comprising: at least one pair of optical fibers having first ends terminating adjacent the nose surface and facing optically forward thereof; said optical fiber first ends spaced apart a selected lateral distance so that their cones of acceptance mutually overlap commencing a short distance in front of the nose surface to define a common volume; one of the optical fibers coupled with a light source for emitting light from its first end for illuminating the surface of an underwater object ahead of the torpedo in its cone of acceptance; the other of the optical fibers adapted to receive in its cone of acceptance light reflected from the surface of the underwater object coming within the common volume of the cones of acceptance and transport that light to its other end; means detecting the transported reflected light at the fiber end and converting it to a responsive first electrical signal; and, means processing the first electrical signal and providing a second electrical signal only after the first electrical signal has decreased to approximately 30% of its peak level; whereby the second electrical signal defines a signal for firing a warhead aboard the torpedo only after the approached object surface has become closer to the torpedo nose surface than in the common volume where maximum light reflection is received.
Claim 9
Dependent Claim 25 words
The invention according to claim 6 further defined by the first ends of the optical fiber pair terminating substantially flush with the torpedo nose surface.
Claim 10
Dependent Claim 21 words
The invention according to claim 7 further defined by a plurality of pairs of optical fibers disposed about the torpedo nose.
Claim 11
Dependent Claim 31 words
The invention according to claim 8 further defined by optical fiber pairs having their ends spaced apart different distances thereby controlling the short distance to the cones of acceptance common volume.
Claim 12
Dependent Claim 18 words
The invention according to claim 8 further defined by different optical fiber pairs having different cones of acceptance.
Claim 13
Independent Claim 151 words
A method of detecting the presence of an object in close proximity in front of a structure surface comprising the steps of: emitting a cone of light in front of the structure surface for illuminating any object coming within its field; receiving light reflected from the illuminated object along a cone of acceptance which partially overlaps with the cone of emitted light commencing shortly in front of the structure surface to define a common volume; generating a first electrical signal responsive to the magnitude of light reflected from an object coming within the field of the common volume; wherein said first electrical signal increases to a peak level as the object approaches into the common volume and decreases as the object departs the common volume; and, processing the first electrical signal to provide a second electrical signal only after the first electrical signal has decreased to substantially below its peak level.
Claim 14
Independent Claim 151 words
A method of detecting the presence of an object in close proximity in front of a structure surface comprising the steps of: emitting a cone of light in front of the structure surface for illuminating any object coming within its field; receiving light reflected from the illuminated object along a cone of acceptance which partially overlaps with the cone of emitted light commencing shortly in front of the structure surface to define a common volume; generating a first electrical signal responsive to the magnitude of light reflected from an object coming within the field of the common volume; wherein said first electrical signal increases to a peak level as the object approaches into the common volume and decreases as the object departs the common volume; and, processing the first electrical signal to provide a second electrical signal only after the first electrical signal has decreased to substantially below its peak level.

References Cited (Backward Citations)

US2060199A Cited
US2060205A Cited
US2255245A Cited
US3554129A Cited
FR2458823A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-02-11 1994-08-13 1995-02-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-02-11 1998-08-13 1999-02-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-02-11 2002-08-13 2003-02-12 $7700.00 Window Closed / Lapsed

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