Dimensioning and Barcode Reading System

• US 20130200150A1
• Filed: 01/28/2013
• Published: 08/08/2013
• Est. Priority Date: 10/16/2007
• Status: Active Grant

• Current Assignee: Datalogic USA, Inc.
• Original Assignee: Accu-Sort Systems Incorporated (Datalogic S.p.A.)
• Inventors: Reynolds, Edward, Hatton, Edward Douglas, Patel, Mehul
• Granted Patent: US 9,230,142 B2
• Time in Patent Office: Days
• US Class Current: 235/438
• 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 camera having an orientation; and

iii. 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 when the calibration object is on the moveable surface;

c. electronically detecting said at least one calibration object at least one indicia and said one or more object features and determining information relating the at least one indicia to the one or more object features based on a value of at least one component of said at least one camera'"'"'s orientation with respect to said moveable surface;

d. electronically revising the value of the at least one component in response to the information.

2. The method of calibrating a barcode scanning tunnel of claim 1, wherein step (a) comprises providing at least one range finder having an orientation, 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 one or more features of said at least one calibration object 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 said 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 least one indicia and said one or more calibration object features comprises 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. each said indicia is formed from a plurality of bars, and

b. a spacing between adjacent said bars of said plurality of bars and a thickness of each bar of said plurality of bars is known.

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 said 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 distal position and said at least one camera using electronics of said at least one camera;

d. measuring a distance between said at least one calibration object at said second proximate 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, wherein step (a) comprises providing at least one range finder having an orientation, said method further comprising calculating a positional relationship of said at least one camera, said 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 step of electronically revising the value of the at least one component 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 at least one camera'"'"'s orientation with respect to said moveable surface is selected from the group consisting of;

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, wherein step (a) comprises providing at least one range finder having an orientation, and the method further comprising:

a. providing a plurality of said 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 each camera with respect to said at least one range finder and said moveable surface.

15. The method of calibrating a barcode scanning tunnel of claim 14, 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. in said step of revising the value of the at least one component comprises revising the value of the at least one component of said orientation of said each camera, wherein said at least one component is selected from the group consisting of;

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. 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 said plurality of cameras and electronically determining information relating the plurality of indicia to the one or more object features based on a value of at least one component of each said camera'"'"'s orientation with respect to the moveable surface; and

e. electronically revising the value of the at least one component of each said camera'"'"'s orientation in response to the information.

17. The method of calibrating a barcode scanning tunnel of claim 16, said step of electronically revising the value of the at least one component of each said camera'"'"'s orientation 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.

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

19. 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 conveyor belt,

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

iv. a calibration box having a predefined length, width and height and a plurality of barcodes disposed in respective 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 said plurality of camera images and determining information about positions of the barcodes on the calibration box based on one or more values of the orientations of the cameras; and

f. electronically revising each of the orientations with respect to said conveyor belt in response to the information.

20. The method of calibrating a barcode scanning tunnel of claim 19, said step of electronically revising the orientations further comprises solving a plurality of simultaneous equations using a non-linear optimization method, wherein each of the orientations with respect to said conveyor belt and said range finder is represented by at least one of said plurality of simultaneous equations.