Cable and line inspection mechanism

• US 6,512,536 B1
• Filed: 02/09/1999
• Issued: 01/28/2003
• Est. Priority Date: 02/09/1999
• Status: Expired due to Fees

• Current Assignee: US Government As Represented By The Director National Security Agency
• Original Assignee: United States Administrator of National Aeronautics and Space Administration
• Inventors: Ross, Terence J.
• Primary Examiner(s): Kelley, Chris
• Assistant Examiner(s): WONG, ALLEN C
• Application Number:
  US09/257,135
• Time in Patent Office: 1,449 Days
• Field of Search: 348/61, 348/82, 348/84, 348/552, 348/91, 390/870.07, 356/640, 376/245, 254/287, 254/333, 254/134, 254/3.R
• US Class Current: 348/61
• CPC Class Codes: G01B 11/105 using photoelectric detection means
• CPC Class Codes: G01N 21/952 Inspecting the exterior surface of cylindrical bodies or wires G01N21/956 takes precedence
• CPC Class Codes: H04N 7/185 from a mobile camera, e.g. for remote control

Abstract

An automated cable and line inspection mechanism visually scans the entire surface of a cable as the mechanism travels along the cable=s length. The mechanism includes a drive system, a video camera, a mirror assembly for providing the camera with a 360 degree view of the cable, and a laser micrometer for measuring the cable=s diameter. The drive system includes an electric motor and a plurality of drive wheels and tension wheels for engaging the cable or line to be inspected, and driving the mechanism along the cable. The mirror assembly includes mirrors that are positioned to project multiple images of the cable on the camera lens, each of which is of a different portion of the cable. A data transceiver and a video transmitter are preferably employed for transmission of video images, data and commands between the mechanism and a remote control station.

Claims

1. An apparatus for systematically inspecting an outer circumferential surface of a generally linear extending cable or line during movement of the apparatus in a direction parallel to the generally linear cable or line to be inspected, comprising:

a) a frame enclosing at least a portion of the cable or line to be inspected;

b) a video camera mounted on said frame for generating a video image of the cable or line to be inspected, said camera including a lens;

c) a mirror assembly mounted on said frame and including at least first and second mirrors, jointly positioned for projecting a plurality of side-by-side images of the cable or line to be inspected on said camera lens, with each of said images being of a different portion of the outer circumference of the cable or line to be inspected, thereby providing said camera lens with views of the entire outer circumference of the cable or line to be inspected including those portions of the circumference facing away from said camera lens; and

d) a drive system for systematically driving said frame along a length of the outer circumference of the cable or line to be inspected as said video camera generates images thereof, said drive system including means for releasably mounting said frame on the cable or line to be inspected.

2. The apparatus of claim 1, further comprising a laser micrometer mounted on said frame for measuring a diameter of a cable or line to be inspected.

3. The apparatus of claim 1, wherein said camera is mounted on said frame and extends in a direction parallel to a longitudinal axis of the cable or line to be inspected, and said apparatus further includes a third mirror disposed adjacent said camera at an angle thereto for reflecting images received from said first and second mirrors at a right angle into said camera lens.

4. The apparatus of claim 1, wherein said drive system further comprises:

1) a drive motor;

2) a motion control circuit for controlling said drive motor;

3) first and second drive wheels for engaging a cable or line to be inspected;

4) first and second tension wheels positioned opposite said first and second drive wheels, respectively, for urging a cable or line to be inspected into engagement with said first and second drive wheels, respectively; and

5) first and second chains for coupling said drive motor to said first and second drive wheels, respectively;

whereby, actuation of said drive motor moves said apparatus along a length of a cable or line to be inspected through rotation of said first and second drive wheels, and said first and second tension wheels, in combination with said first and second drive wheels, secure said frame to a cable or line to be inspected.

5. The apparatus of claim 1, further comprising a position encoder mounted on said frame for determining a position of said apparatus along a length of a cable to be inspected.

6. The apparatus of claim 1, further comprising:

e) a processor unit interfaced to said drive system for controlling operation thereof.

7. The apparatus of claim 6, further comprising:

f) a video transmitter mounted on said frame for transmitting video signals generated by said camera;

g) a first RF transceiver mounted on said frame for facilitating communication of data and commands to and from said processor unit; and

h) a remote control station including;

1) a computer;

2) a video receiver interfaced to said computer for receiving video signals from said video transmitter; and

3) a second RF transceiver for communicating with said first RF transceiver, said second RF transceiver being interfaced to said computer.

8. The apparatus of claim 1, further including a video overlay circuit interfaced to said video camera and said video transmitter for overlaying identification information on a video image generated by said camera.

9. The apparatus of claim 1, further comprising a video storage device mounted on said frame for receiving and storing video images generated by said camera.

10. The apparatus of claim 1, further comprising a power supply disposed on said frame for supplying power to said camera and said drive system.

11. The apparatus of claim 1, further including switch means mounted on an end of said frame for sensing when said frame contacts a structure at an end of a cable or line to be inspected, and causing said drive system to reverse direction of movement of said frame, and return said frame to a starting point.

12. An apparatus for systematically inspecting an outer circumferential surface of a generally linear extending cable or line during movement of the apparatus in a direction parallel to the cable or line to be inspected, comprising:

a) a frame enclosing a least a portion of the cable or line to be inspected;

b) a video camera mounted on said frame for generating a video image of the cable or line to be inspected, said camera including a lens;

c) a mirror assembly mounted on said frame for projecting a plurality of side-by-side images of the cable or line to be inspected on said camera lens, with each of said images being of a different portion of the outer circumference of the cable or line to be inspected, thereby providing said camera lens with views of the entire outer circumference of the cable or line to be inspected including those portions of the outer circumference facing away from the camera lens;

d) a drive system for physically engaging opposite sides of the cable or line to be inspected and systematically driving said frame parallel to the cable or line to be inspected as said video camera generates images thereof, said drive system including means for mounting said frame on the cable or line to be inspected, said means for mounting including two pairs of spaced-apart wheels frictionally engaging opposite sides of the outer circumference of the generally linear cable or line to be inspected;

e) a laser micrometer mounted on said frame for determining a position of said apparatus along a length of the cable or line to be inspected;

f) a position encoder mounted on said frame for determining a position of said apparatus along a length of the cable or line to be inspected;

g) a processor unit mounted on said frame, and interfaced to said drive system, said micrometer and said encoder for controlling operation thereof and receiving data therefrom; and

h) a power supply disposed on said frame for supplying power to said camera, said drive system, said micrometer, said encoder and said processor.

13. The apparatus of claim 12, wherein said mirror assembly includes first and second mirrors for directing to said camera lens, reflected images of first and second portions of a cable or line to be inspected that face away from said camera lens.

14. The apparatus of claim 13, wherein said camera is mounted in said frame in a direction parallel to a longitudinal axis of a cable or line to be inspected, and said apparatus further includes a third mirror disposed adjacent said camera lens at an angle thereto for reflecting images received from said first and second mirrors at a right angle into said camera lens.

15. The apparatus of claim 12, wherein said drive system further comprises:

1) a drive motor;

2) a motion control circuit for controlling said drive motor, said motion control circuit being interfaced to said processor unit;

3) first and second drive wheels for engaging a cable or line to be inspected;

4) first and second tension wheels positioned opposite said first and second drive wheels, respectively, for urging a cable or line to be inspected into engagement with said first and second drive wheels, respectively; and

5) first and second chains for coupling said drive motor to said first and second drive wheels, respectively;

whereby, actuation of said drive motor moves said apparatus along a length of a cable or line to be inspected through rotation of said first and second drive wheels, and said first and second tension wheels, in combination with said first and second drive wheels, secure said frame to a cable or line to be inspected.

16. The apparatus of claim 12, further comprising:

i) a video transmitter mounted on said frame for transmitting video signals generated by said camera;

j) a first RF transceiver mounted on said frame for facilitating communication of data and commands to and from said processor unit; and

k) a remote control station including;

1) a computer;

2) a video receiver interfaced to said computer for receiving video signals from said video transmitter; and

3) a second RF transceiver for communicating with said first RF transceiver, said second RF transceiver being interfaced to said computer.

17. The apparatus of claim 12, further including switch means mounted on an end of said frame and interfaced to said processor unit for sensing when said frame contacts a structure at an end of a cable or line to be inspected, and causing said motor to reverse direction and return said frame to a starting point.

18. The apparatus of claim 12, further including a video overlay circuit interfaced to said video camera for overlaying information on a video image generated by said camera, said information including cable diameter data generated by said micrometer, and cable position data generated by said position encoder.

19. The apparatus of claim 12, further comprising a video storage device mounted on said frame for receiving and storing video images generated by said camera.