System, method, and apparatus for optical character recognition of labeled conductors while matching harnesses of conductors with apertures in connectors

• US 20050235491A1
• Filed: 06/10/2005
• Published: 10/27/2005
• Est. Priority Date: 12/30/2003
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Macnutt, William Phillip, Malleck, Richard A.
• Granted Patent: US 7,647,695 B2
• Time in Patent Office: Days
• US Class Current: 29/868
• CPC Class Codes: H01R 9/2475 Means facilitating correct wiring, e.g. marking plates, identification tags
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/49139 by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base
• CPC Class Codes: Y10T 29/49153 with shaping or forcing terminal into base aperture
• CPC Class Codes: Y10T 29/49174 Assembling terminal to elongated conductor
• CPC Class Codes: Y10T 29/49194 Assembling elongated conductors, e.g., splicing, etc.
• CPC Class Codes: Y10T 29/53213 Assembled to wire-type conductor
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

An OCR system for matching wire harnesses and connectors facilitates precise registration of wire number strings, uses geometric modeling for character recognition, and restricts searches by region and character to ensure speed and accuracy. A string location algorithm is used to search for and identify the location of the beginning of a wire number string. The horizontal edges of the wire in the image are located, a diameter of the wire is determined, light intensity is confirmed, and the first character is found. The resulting coordinate is used by the algorithm for character definition. Geometric shapes are used for identification in order to overcome twisted wires, poorly printed markings, ink color variations, and contacting characters.

Claims

1. A method of optical character recognition of identifying information on a workpiece, the method comprising:

(a) positioning the identifying information of the workpiece adjacent a reader;

(b) searching for and identifying a beginning of the identifying information;

(c) locating edges of the workpiece in an image thereof;

(d) determining a dimension of the workpiece;

(e) confirming a light intensity of the image;

(f) finding a first character of the identifying information;

(g) using geometric shapes as a basis for identifying the first character; and

then

(h) sequentially repeating step (g) for any additional characters in the identifying information until the identifying information is confirmed.

2. A method according to claim 1, wherein every character in the identifying information is identified.

3. A method according to claim 1, further comprising providing access to a workpiece database including identifying information;

and

comparing at least one of the identified characters in the identifying information to the workpiece database.

4. A method according to claim 3, further comprising checking characters for all possible characters that could be in each position based on the workpiece database.

5. A method according to claim 3, further comprising identifying fewer than all of the characters in the identifying information when a unique component of the identifying information is confirmed.

6. A method according to claim 1, wherein the identifying information is identified character by character, and step (f) is restricted to an area surrounding the first character.

7. A method according to claim 1, further comprising defining a character width based on a width of the first character, and limiting subsequent character searches to the character width.

8. A method according to claim 1, wherein the identifying information comprises a string of characters.

9. A method according to claim 1, wherein step (b) comprises searching for and identifying an XY location of the beginning of the identifying information.

10. A method according to claim 1, wherein step (c) comprises using edge detection techniques to locate edges of the workpiece in the image thereof.

11. A method according to claim 1, wherein step (d) comprises determining a diameter of a wire comprising the workpiece.

23. A method according to claim 1, further comprising providing access to a conductor database including the conductor information;

and

comparing at least one of the identified characters in the conductor information to the conductor database.

24. A method according to claim 23, further comprising checking characters for all possible characters that could be in each position based on the conductor database.

25. A method according to claim 23, further comprising identifying fewer than all of the characters in the conductor information when a unique component of the conductor information is confirmed.

12. A system for matching a harness of conductors with apertures in a connector, the system comprising:

a harness having a plurality of conductors, each of the conductors having a label;

a connector having a plurality of apertures for receiving the conductors;

a computer having a visual display for displaying information to a user;

a data base coupled to the computer, the data base having information regarding the conductors and the connector;

an optical character recognition (OCR) system coupled to the computer for reading the labels associated with the conductors; and

a light array coupled to the computer and connectable to the connector, the light array having a plurality of light conductors for illuminating individual ones of the apertures in the connector in response to commands from the computer in order to designate to the user the aperture in which each conductor should be located.

13. A system according to claim 12, wherein the OCR system comprises a reader head having a camera, a camera processor, a light control, a computer including a frame grabber, and software for processing images of the conductors and their labels and communicating information to the user.

14. A system according to claim 13, wherein the reader head comprises a slot for receiving a conductor, a pair of mirrors mounted adjacent the slot for reflecting images of the received conductor, and LEDs for illuminating the received conductor.

15. A system according to claim 14, wherein the OCR system displays an image of the received conductor composed from the received conductor and the two reflected images.

16. A system according to claim 12, further comprising an input/output expander circuit coupled between the computer and the light array, the input/output expander circuit having a communication cable extending to the computer, and a light cable extending to the light array.

17. A system according to claim 12, wherein the light array back-lights a selected one of the apertures in the connector for the user to indicate the aperture in which a selected one of the conductors should be inserted.

18. A system according to claim 12, wherein the visual display of the computer graphically illustrates a selected one of the apertures in the connector to indicate the aperture in which a selected one of the conductors should be inserted.

19. A system according to claim 12, wherein the light array comprises a cover plate, an array of LEDs mounted to a circuit board on the cover plate, a separation plate mounted to the cover plate over the array of LEDs, a light rod guide plate mounted to the separation plate, a mating connector for coupling with the connector and having a plurality of apertures, a light rod extending between each of the apertures in the mating connector and each of the LEDs, and a covering for integrating components of the light array.

20. A method of matching a harness of conductors with apertures in a connector, the method comprising:

(a) providing a harness having a plurality of conductors, and a connector having a plurality of apertures for receiving the conductors;

(b) reading information from one of the conductors with OCR and inputting the information related to said one of the conductors into a computer;

(c) displaying information on the computer;

(d) illuminating a corresponding one of the apertures in the connector via a command from the computer;

(e) inserting said one of the conductors into said corresponding one of the apertures; and

then

(f) repeating steps (b) through (e) for another one of the conductors until all of the conductors are terminated in the connector.

21. A method according to claim 20, wherein step (b) comprises

positioning the conductor information adjacent a reader;

searching for and identifying a beginning of the conductor information;

locating edges of the conductor in an image thereof;

determining a diameter of the conductor;

confirming a light intensity of the image;

finding a first character of the conductor information;

using geometric shapes as a basis for identifying the first character; and

then

sequentially repeating the using geometric shapes step for any additional characters in the conductor information until the conductor information is confirmed.

22. A method according to claim 20, wherein every character in the conductor information is identified.

26. A method according to claim 21, wherein the conductor information is identified character by character, and a search for a character is restricted to an area surrounding the first character.

27. A method according to claim 21, further comprising defining a character width based on a width of the first character, and limiting subsequent character searches to the character width.

28. A method according to claim 21, further comprising searching for and identifying an XY location of the beginning of the conductor information.