Sorting and inspection apparatus and method

• US 4,414,566 A
• Filed: 04/03/1981
• Issued: 11/08/1983
• Est. Priority Date: 04/03/1981
• Status: Expired due to Fees

• Current Assignee: Industrial Automation Corp (Southern Company)
• Original Assignee: Industrial Automation Corp (Southern Company)
• Inventors: Thomason, Robert L., Peyton, John J., Evinger, Hubert W.
• Primary Examiner(s): BRITTON, HOWARD W
• Application Number:
  US06/250,780
• Time in Patent Office: 949 Days
• Field of Search: 358/93, 358/101, 358/106, 358/107, 364/728, 364/478, 364/514-517, 364/705, 198/340, 209/522, 209/524, 209/526, 209/528, 209/939, 250/223 B, 356/240, 356/394, 356/71, 382/42
• US Class Current: 382/142
• CPC Class Codes: B07C 5/10 measured by light-responsive means sorting according to colour B07C5/342
• CPC Class Codes: G01N 2033/0081 containers; packages; bottles
• CPC Class Codes: G06F 18/21 Design or setup of recognition systems or techniques; Extraction of features in feature space; Blind source separation
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G06V 10/421 by analysing segments intersecting the pattern
• CPC Class Codes: G06V 10/70 using pattern recognition or machine learning optical pattern recognition or electronic computations therefor G06V10/88
• CPC Class Codes: G06V 20/66 Trinkets, e.g. shirt buttons or jewellery items recognising microscopic objects G06V20/69
• CPC Class Codes: Y10S 209/939 Video scanning

Abstract

Sorting and inspection apparatus and methods which may be used for the identification and separation of articles of different characteristics, or the inspection of articles of similar characteristics to reject those of below minimum standards. A typical system will include a transport system for individually transporting the articles past a television camera so that the camera may view the distinctive portions of the articles to be sorted or the area of the articles to be inspected. The output of the television camera is digitized based upon the number of transitions of light to dark (or dark to light) in the scan lines. A correlator then performs a specialized correlation between the digitized image and various previously digitized images representing the different items being sorted or inspected, to determine which of the previously stored images best correlates with the digitized image from the television camera. A second correlation may be done using a different correlation technique, if desired, to make the final decision based upon the extent of differences between the prestored digitized images and the digitized image from the television camera. The prestored digitized images may be initially created or stored by placing an article with the characteristic to be recognized in front of the television camera and then recording the digitized image. Many refinements and alternate embodiments are disclosed.

Claims

1. In a bottle sorting system, the improvement comprising

video camera means for receiving at least one two-dimensional image of at least a visually distinctive portion of a target bottle within the field of view of said video camera and for providing a video signal in response thereto

digitizing means coupled to said camera means for providing a first plurality of digital signals responsive to said video signal, each said digital signal summarizing, in digital form, the features of a respective portion of the target bottle

storage means for storing second pluarlities of digital signals, each of said digital signals within one of said second pluralities of digital signals summarizing, in digital form, the features of a respective portion of a bottle of one of the predetermined types of bottle to be sorted;

and

correlation means for correlating said first plurality of digital signals with each of said second plurality of digital signals to identify which of said predetermined types of bottles the target bottle most closely correlates.

2. The improvement of claim 1 wherein each digital signal summarizing, in digital form, the features of a respective portion of the target bottle summarizes at least one raster scan line of the target bottle image.

3. The improvement of claim 2 wherein each digital signal summarizes, in digital form, the features of the target bottle is a binary coded digital signal.

4. The improvement of claim 1 wherein each digital signal summarizes, in digital form, the features of a respective portion of the target bottle in one raster scan line of the target bottle image.

5. The improvement of claim 4 wherein each digital signal summarizes, in digital form, the features of the target bottle is a coded digital signal.

6. The improvement of claim 1 further comprised of transport means for successively transporting bottles past a target position, whereby said video camera may receive an image of at least a visually distinctive portion thereof.

7. The improvement of claim 6 further comprised of a strobe light to illuminate a bottle at the target position whereby said video camera may receive a strobed image of each target bottle.

8. The improvement of claim 7 further comprised of a trigger means to trigger said strobe upon the arrival of a bottle at the target position.

9. The improvement of claim 8 wherein said trigger means is also a means for triggering said digitizing means whereby a new image is digitized for correlation.

10. The improvement of claim 7 further comprised of a polarizing filter over the lens of said video camera.

11. The improvement of claim 10 further comprised of a polarizing filter over said strobe to polarize the illumination of the target bottle.

12. The improvement of claim 11 wherein said polarizing filters are aligned to minimize reflections of the strobe light in the image received by said video camera.

13. The improvement of claim 1 wherein each said digitizing means is a means for sensing transitions in image intensity on the raster scan of said video camera and providing as each respective said digital signal, a signal responsive to the number of transitions in a predetermined portion of the raster scan.

14. The improvement of claim 13 wherein said predetermined portion of the raster scan is one line of said raster scan.

15. The improvement of claim 1 wherein said digitizing means is a means for sensing regions of particular intensity of the raster scan image and providing as each said digital signal, a signal responsive to the length of the regions of the particular intensity in a predetermined portion of the raster scan.

16. The improvement of claim 15 wherein said predetermined portion of the raster scan is one line of said raster scan.

17. The improvement of claim 1 further comprised of

means for determining the margin in correlations between the correlation obtained between a target bottle and a first predetermined type of bottle with which the digital signals best correlate, and the correlation obtained between the target bottle and a second predetermined type of bottle with which the digitized signals next best correlate, and

second correlation means for correlating said first plurality of digital signals with each of said second plurality of digital signals for said first and second predetermined types of bottles utilizing a correlation technique differing from the correlation technique used in the first correlation when the margin in correlation is less than a predetermined amount.

31. The improvement of claim 1 wherein said video camera means is a means for receiving an image comprised of at least part of the label on the target bottle, and said digitizing means is a means for providing said first plurality of digital signals, each said digital signal summarizing, at least in part, and in digital form, the features of the respective part of the label on the target bottle.

32. The improvement of claim 31 wherein said correlation means further includes precessing means for correlating said first and second pluralities of digital signals with various amounts of precess to accommodate locational differences in the target bottle and the predetermined types of bottles.

33. The improvement of claim 32 further comprised of

means for determining the margin in correlations between the correlation obtained between a target bottle and a first predetermined type of bottle with which the digital signals best correlate, and the correlation obtained between the target bottle and a second predetermined type of bottle with which the digitized signals next best correlate, and

second correlation means for correlating said first plurality of digital signals with each of said second plurality of digital signals for said first and second predetermined types of bottles utilizing a correlation technique differing from the correlation technique used in the first correlation when the margin in correlation is less than a predetermined amount.

34. The improvement of claim 31 wherein said video camera means is a means for receiving an image comprised of at least part of a substantially opaque label on the target bottle.

35. The inspection apparatus of claim 34 wherein said correlation means further includes precessing means for correlating said first and second pluralites of digital signals with various amounts of precess to accommodate locational differences in the target bottle and the predetermined bottle types.

36. The improvement of claim 35 further comprised of

means for determining the margin in correlations between the correlation obtained between a target bottle and a first predetermined type of bottle with which the digital signals best correlate, and the correlation obtained between the target bottle and a second predetermined type of bottle with which the digitized signals next best correlate, and

second correlation means for correlating said first plurality of digital signals with each of said second plurality of digital signals for said first and second predetermined types of bottles utilizing a correlation technique different from the correlation technique used in the first correlation when the margin in correlation is less than a predetermined amount.

18. Inspection apparatus comprising

video camera means for receiving a two-dimensional an image of at least the portion of an article to be inspected within the field of view of said video camera and for providing a raster scan video signal in response thereto

digitizing means coupled to said camera means for providing a first plurality of digitized signals responsive to the said raster scan video signal, each digital signal summarizing, in digital form, the characteristic of a respective portion of the raster scan of the image of the article to be inspected

storage means for storing a second plurality of digital signals, each of said digital signals within said second plurality of digital signals summarizing, in digital form, the features of a respective portion of the raster scan of an image of a preselected article having the specific characteristic to be inspected for;

and

correlation means for correlating said first plurality of digital signals with said second plurality of digital signals to determine the similarity in the article being inspected and the preselected article.

19. The inspection apparatus of claim 18 wherein said digitizing means is a means for providing said first plurality of digital signals during the raster scan of the image of the article being inspected.

20. The inspection apparatus of claim 19 wherein said first and second plurality of digitized signals are binary coded digital signals.

21. The inspection apparatus of claim 20 wherein said correlation means is a means for correlating said first and second plurality of digital signals after all of said first plurality of digital signals for the article being inspected have been determined by said digitizing means.

22. The inspection apparatus of claim 21 wherein said correlation means further includes precessing means for correlating said first and second pluralities of digital signals with various amounts of precess to accommodate locational differences in the article being inspected and the preselected article.

23. The inspection apparatus of claim 21 further comprised of transport means for successively delivering articles to be inspected to the field of view of said video camera, and utilization means responsive to said correlation means for effecting the disposition of the article being inspected.

24. The apparatus of claim 23 wherein said storage means is a means for storing second pluralities of digital signals, each of said digital signals within one of said second pluarities of digital signals summarizing in digital form, characteristics to be inspected for, and means responsive to said correlation means for effecting the disposition of the article being inspected.

25. The apparatus of claim 24 wherein said apparatus further includes means for storing said second pluralities of digital signals when preselected articles are placed within the field of view of said video camera, whereby the specific characteristics to be inspected for may be changed as desired.

26. The apparatus of claim 19 wherein said apparatus further includes means for storing said second plurality of digital signals when the preselected article is placed within the field of view of said video camera camera, whereby the specific characteristics to be inspected for may be changed as desired.

27. A method of inspecting articles comprising the steps of

(a) storing a first plurality of digital signals, each representing a summary of the features of the raster scan of an item to be inspected for

(b) placing the article to be inspected in view of a video camera to obtain a raster scan video signal responsive to the image of at least part of the article to be inspected

(c) digitizing the video signal to provide a second plurality of digital signals, each representing a summary of features of the article to be inspected as represented by a portion of the raster scan, and

(d) correlating the digital signals of step (a) and step (c) to determine the similarities thereof.

28. The method of claim 27 wherein said first and second digital signals are binary coded digital signals.

29. The method of claim 27 wherein step (a) comprises the step of storing a first pluralities of digital signals, each digital signal in each plurality representing a summary of the features of the raster scan of a respective item to be inspected for, and step (d) comprises the step of correlating the digital signals of step (a) and step (c) to determine which of the items to be inspected for the article to be inspected most closely conforms.

30. The method of claim 29 comprised of the additional steps of determining the margin of correlation between the article to be inspected and (i) the item to which said digital signals of said article best correlates, and (ii) the item to which said digital signals of said article next best correlates, and if that margin is less than a predetermined amount, performing an additional and different correlation using the digital signals for the items determining the margin.

37. In a bottle sorting system, the improvement comprising

video camera means for receiving an image of at least a visually distinctive portion of a target bottle within the field of view of said video camera and for providing a video signal in response thereto

digitizing means coupled to said camera means for providing a first plurality of digitized signals responsive to said video signal, each digital signal summarizing, in digital form, the features of a respective portion of the target bottle

storage means for storing second pluralities of digital signals, each of said digital signals within one of said second pluralities of digital signals summarizing, in digital form, the features of a respective portion of a bottle of one of the predetermined types of bottle to be sorted

correlation means for correlating said first plurality of digital signals with each of said plurality of digital signals to identify which of said predetermined types of bottles the target bottle most closely correlates

means for determining the margin in correlations between the correlation obtained between a target bottle and a first predetermined type of bottle with which the digital signals best correlate, and the correlation obtained between the target bottle and a second predetermined type of bottle with which the digitized signals next best correlate, and

second correlation means for correlating said first plurality of digital signals with each of said second plurality of digital signals for said first and second predetermined types of bottles utilizing a correlation technique differing from the correlation technique used in the first correlation when the margin in correlation is less than a predetermined amount.

38. In a bottle sorting system, the improvement comprising

video camera means for receiving an image of at least a visually distinctive portion of a target bottle within the field of view of said video camera and for providing a video signal in response thereto

digitizing means coupled to said camera means for providing a first plurality of digitized signals responsive to said video signal, each digital signal summarizing, in digital form, the features of a respective portion of the target bottle

storage means for storing second pluralities of digital signals, each of said digital signals within one of said second pluralities of digital signals summarizing, in digital form, the features of a respective portion of a bottle of one of the predetermined types of bottle to be sorted;

and

correlation means for correlating said first plurality of digital signals with each of said second plurality of digital signals to identify which of said predetermined types of bottles the target bottle most closely correlates, said correlation means further including precessing means for correlating said first and second pluralities of digital signals with various amounts of precess to accommodate locational differences in the article being inspected and each predetermined type of bottle.

39. Inspection apparatus comprising

video camera means for receiving an image of at least the portion of an article to be inspected within the field of view of said video camera and for providing a raster scan video signal in response thereto

digitizing means coupled to said camera means for providing a first plurality of digitized signals responsive to the said raster scan video signal, each digital signal summarizing, in digital form, the characteristic of a respective portion of the raster scan of the image of the article to be inspected

storage means for storing a second plurality of digital signals, each of said digital signals within said second plurality of digital signals summarizing, in digital form, the features of a respective portion of the raster scan of an image of a preselected article having the specific characteristic to be inspected for

correlation means for correlating said first plurality of digital signals with said second plurality of digital signals to determine the similarity in the article being inspected and the preselected article, said correlation means further including precessing means for correlating said first and second pluralities of digital signals with various amount of precess to accommodate locational differences in the article being inspected and the preselected article.