DIMENSIONING AND BARCODE READING SYSTEM

• US 20090095047A1
• Filed: 10/15/2008
• Published: 04/16/2009
• Est. Priority Date: 10/16/2007
• Status: Abandoned Application

• Current Assignee: Accu-Sort Systems Incorporated (Datalogic S.p.A.)
• Original Assignee: Accu-Sort Systems Incorporated (Datalogic S.p.A.)
• Inventors: Reynolds, Edward, Patel, Mehul, Hatton, Edward Douglas
• Application Number:
  US12/251,626
• Publication Number:
  US 20090095047A1
• Time in Patent Office: Days
• US Class Current: 73/1.01
• CPC Class Codes: G06K 7/0095 Testing the sensing arrangement, e.g. testing if a magnetic card reader, bar code reader, RFID interrogator or smart card reader functions properly testing of electrical circuits G01R31/28
• CPC Class Codes: G06K 7/015 Aligning or centering of the sensing device with respect to the record carrier
• CPC Class Codes: G06K 7/10722 Photodetector array or CCD scanning
• CPC Class Codes: G06K 7/10762 Relative movement
• CPC Class Codes: G06K 7/10792 Special measures in relation to the object to be scanned
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48

Abstract

A system and method for auto-calibrating a barcode scanning tunnel to determine the orientation of one or more cameras with respect to a range finder and a conveyor belt comprises providing a scanning tunnel having a moveable surface, at least one range finder having an orientation, at least one camera having an orientation and at least one calibration object having at least one indicia disposed in a predetermined relationship to one or more features of the at least one calibration object, capturing at least one image of the at least one calibration object by the at least one camera, electronically detecting the at least one calibration object at least one indicia and the one or more object features and electronically calculating at least one component of the at least one camera orientation with respect to the moveable surface in response to information obtained from the image and the at least one calibration object at least one indicia.

Claims

1. A method of calibrating a barcode scanning tunnel, said method comprising:

a. providing a scanning tunnel having

i. a moveable surface,

ii. at least one range finder having an orientation,

iii. at least one camera having an orientation; and

iv. at least one calibration object having at least one indicia disposed in a predetermined relationship to one or more features of said at least one calibration object;

b. capturing at least one image of said at least one calibration object by said at least one camera;

c. electronically detecting said at least one calibration object at least one indicia and said one or more object features;

d. electronically calculating at least one component of said at least one camera orientation with respect to said moveable surface in response to information obtained from said image and said at least one calibration object at least one indicia.

2. The method of calibrating a barcode scanning tunnel of claim 1, said method further comprising electronically calculating a height and extents of said at least one calibration object by said at least one range finder by electronically detecting said one or more calibration object features.

3. The method of calibrating a barcode scanning tunnel of claim 1, wherein said at least one indicia is a barcode.

4. The method of calibrating a barcode scanning tunnel of claim 3, further comprising a plurality of indicia disposed in a predetermined relationship to said one or more features of said at least one calibration object.

5. The method of calibrating a barcode scanning tunnel of claim 1, wherein said at least one or more features of said at least one calibration object further comprises at least one of a length, width and height of said at least one calibration object.

6. The method of calibrating a barcode scanning tunnel of claim 1, further comprising providing a second calibration object having a plurality of indicia disposed in a predetermined relationship to one or more features of said second calibration object.

7. The method of calibrating a barcode scanning tunnel of claim 4, wherein said predetermined relationship between said at lease one indicia and said one or more calibration object features further comprises knowing the distance of said at least one indicia from one or more edges of said calibration object.

8. The method of calibrating a barcode scanning tunnel of claim 6, wherein

a. said at least one indicia is formed from a plurality of bars, and

b. a spacing between adjacent bars of said plurality of bars and the thickness of each bar of said plurality of bars is know with respect to said at least one or more calibration object features.

9. The method of calibrating a barcode scanning tunnel of claim 1, further comprising:

a. placing said at least one calibration object at a first position on said moveable surface when said moveable surface is stationary;

b. placing said at least one calibration object at a second position on said moveable surface when said moveable surface is stationary;

c. capturing a first image of said at least one calibration object at said first position;

d. capturing a second image of said at least one calibration object at said second position; and

e. electronically calculating a region of interest based on information contained in aid first image and said second image related to said one or more features of said at least one calibration object.

10. The method of calibrating a barcode scanning tunnel of claim 9, further comprising

a. placing said at least one calibration object at a first position distal from said at least one camera on said moveable surface when said moveable surface is stationary;

b. placing said at least one calibration object at a second position proximate to said at least one camera on said moveable surface when said moveable surface is stationary;

c. measuring a distance between said at least one calibration object at said first position and said at least one camera using the electronics of said at least one camera;

d. measuring a distance between said at least one calibration object at said second position and said at least one camera using the electronics of said at least one camera; and

e. electronically calculating a height of said at least one camera with respect to a surface of said moveable surface.

11. The method of calibrating a barcode scanning tunnel of claim 1, said method further comprising calculating a positional relationship of said at least one camera, said at least one moveable surface and said at least one range finder with respect to one another.

12. The method of calibrating a barcode scanning tunnel of claim 11, wherein said electronically calculating at least one component of said at least one camera orientation with respect to said moveable surface further comprises

a. calculating a relationship of said at least one calibration object indicia with respect to said one or more calibration object features;

and

b. comparing said calculated relationship to said predetermined relationship.

13. The method of calibrating a barcode scanning tunnel of claim 1, wherein

a. said moveable surface defines an x-axis in a direction of travel of said moveable surface, a z-axis normal to a top surface of said moveable surface and a y-axis transverse to said direction of travel of said moveable surface;

and

b. said at least one component of said orientation of said at least one camera with respect to said moveable surface is chosen from;

i. a z-axis offset from said moveable surface;

ii. a pitch angle with respect to said moveable surface x-axis;

iii. a yaw angle with respect to said moveable surface z-axis; and

iv. a roll angle with respect to said moveable surface y-axis.

14. The method of calibrating a barcode scanning tunnel of claim 1, further comprising

a. providing a plurality of cameras each having an orientation with respect to said moveable surface and said at least one range finder;

and

b. networking said plurality of cameras and said at least one range finder,

wherein said networked plurality of cameras and said at least one range finder share information to electronically calculate at least one component of said orientation of said at least one camera with respect to said at least one range tinder and said moveable surface.

15. The method of calibrating a barcode scanning tunnel of claim 16, wherein

a. said moveable surface defines an x-axis in a direction of travel of said moveable surface, a z-axis normal to a top surface of said moveable surface and a y-axis transverse to said direction of travel of said moveable surface;

and

b. said calculating at least one component of said orientation of said at least one camera with respect to said moveable surface further comprises calculating at least one component of said orientation of each of said plurality of camera, wherein each of said at least one components are chosen from;

i. an x-axis offset from said at least one range finder;

ii. a y-axis offset from said at least one range finder;

iii. a z-axis offset from said moveable surface;

iv. a pitch angle with respect to said moveable surface x-axis;

v. a yaw angle with respect to said moveable surface z-axis; and

vi. a roll angle with respect to said moveable surface y-axis.

16. The method of calibrating a barcode scanning tunnel of claim 1, said step of electronically calculating at least one component for said at least one camera orientation further comprises solving a plurality of simultaneous equations using a non-linear optimization method, wherein said plurality of simultaneous equations represent said at least one camera orientation with respect to said moveable surface.

17. The method of calibrating a barcode scanning tunnel of claim 16, wherein said non-linear optimization method is a Nelder-Mead method.

18. A method of calibrating a barcode scanning tunnel, said method comprising:

a. providing a scanning tunnel having

i. a moveable surface,

ii. a range finder having an orientation with respect to said moveable surface,

iii. a plurality of cameras each having an orientation with respect to said movable surface and said range finder; and

iv. a first and a second calibration object each having a plurality of indicia disposed in predetermined relationships to one or more features of each of said first and second calibration objects;

b. capturing a first image of said first calibration object by each of said plurality of cameras;

c. capturing a second image of said second calibration object by each of said plurality of cameras;

d. electronically detecting each of said first and said second calibration object plurality of indicia visible in each of said first images and said second images and each of said one or more object features of said first and said second calibration objects by each of said plurality of cameras; and

e. electronically calculating at least one component for each of said plurality of camera orientations with respect to said moveable surface in response to information obtained from each of said first and said second camera images.

19. The method of calibrating a barcode scanning tunnel of claim 18, said step of electronically calculating at least one component for each of said plurality of camera orientations further comprises solving a plurality of simultaneous equations using a non-linear optimization method, wherein one of each of said plurality of simultaneous equations represents said orientation of at least one of said plurality of cameras with respect to said moveable surface.

20. The method of calibrating a barcode scanning tunnel of claim 19, wherein said non-linear optimization method is a Nelder-Mead method.

23. The method of calibrating a barcode scanning tunnel of claim 19, wherein said non-linear optimization method is a Nelder-Mead method.

21. A method of calibrating a barcode scanning tunnel, said method comprising:

a. providing a scanning tunnel having

i. a conveyor belt,

ii. a range finder having an orientation with respect to said moveable surface,

iii. a plurality of cameras each having an orientation with respect to said movable surface and said range finder; and

iv. a calibration box having a predefined length, width and height and a plurality of barcodes disposed in predetermined relationships to at least one edge of said calibration box;

b. capturing at least one image of said calibration box by said range finder;

c. capturing an image of said calibration box by each of said plurality of cameras;

d. electronically detecting at least one of said length, said width and said height of said calibration box from said at least one range finder image;

e. electronically detecting at least one of said calibration box plurality of barcodes in each of said plurality of camera images; and

f. electronically calculating each of said plurality of camera orientations with respect to said moveable surface in response to information obtained from each of said plurality of camera images.

22. The method of calibrating a barcode scanning tunnel of claim 21, said step of electronically calculating each of said plurality of camera orientations further comprises solving a plurality of simultaneous equations using a non-linear optimization method, wherein each of said plurality of camera orientations with respect to said conveyor belt and said range finder is represented by at least one of said plurality of simultaneous equations.

24. A method of calibrating a barcode scanning tunnel, said method comprising:

a. providing a scanning tunnel having

i. a conveyor belt,

ii. a range finder having an orientation with respect to said moveable surface,

iii. a plurality of cameras each having an orientation with respect to said movable surface and said range finder, and

iv. a plurality of calibration boxes each having a predefined length, width and height and each containing a plurality of barcodes disposed in predetermined relationship to at least one edge of said respective calibration box;

b. capturing a plurality of images of each of said plurality of calibration boxes by said range finder as each of said plurality of calibration boxes move along said conveyor belt;

c. capturing a plurality of images of each of said plurality of calibration boxes by each of said plurality of cameras as each of said plurality of calibration boxes move along said conveyor belt;

d. electronically detecting said length, said width and said height of each of said calibration boxes from said plurality of range finder images;

e. electronically detecting in each of said plurality of camera images of each of said plurality of calibration boxes at least one of said calibration box plurality of barcodes;

f. calculating the relationship of each of said detected barcodes with respect to said at least one edge of said respective calibration box; and

g. electronically calculating each of said plurality of camera orientations based on said calculated relationship of each of said detected barcodes with respect to said at least one edge of said respective calibration box and its respective said predetermined relationship.