Method of controlling cross-direction alignment in manufacturing process

• US 6,856,859 B1
• Filed: 06/22/1999
• Issued: 02/15/2005
• Est. Priority Date: 12/31/1998
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Lemery, Shawn Timothy, Brumm, Russell Joseph, Ungpiyakul, Tanakon, Bett, Thomas Arthur
• Primary Examiner(s): MCCLELLAN, JAMES S
• Application Number:
  US09/338,238
• Time in Patent Office: 2,065 Days
• Field of Search: 700/222, 700/59, 700/62, 700/110, 156/351, 226/15, 226/19, 226/20
• US Class Current: 700/222
• CPC Class Codes: A61F 13/15772 Control
• CPC Class Codes: B65H 2220/01 indicating an entity as a function of which control, adjustment or change is performed, i.e. input
• CPC Class Codes: B65H 2220/09 indicating that several of an entity are present
• CPC Class Codes: B65H 2301/3611 centering, positioning material symmetrically relatively to a given axis of displacement
• CPC Class Codes: B65H 2511/413 of image
• CPC Class Codes: B65H 2553/42 Cameras
• CPC Class Codes: B65H 39/16 Associating two or more webs

Abstract

Control processes control cross direction alignment of elements being assembled as work pieces on a manufacturing line fabricating preferably absorbent article products on a continuous substrate web. The method defines a manufacturing line path traversed by the work pieces, defines a reference path along the manufacturing path, and establishes the elements on the work pieces. A camera is mounted along the manufacturing line. An image window of the camera is referenced to the reference path. The camera captures full digitized visual images of work pieces. The camera is part of a vision imaging inspection and control system which inspects and evaluates images of the work pieces, including the cross-direction positions of the elements on the work pieces, against established acceptable positions relative to the reference path. When an element is out of alignment, the control system can display visual cues identifying the elements that are inconsistent with acceptable ranges. The full digitized images can be selectively stored in permanent memory, retrieved from permanent memory, and analyzed off-line. The machines are adjusted to adjust positioning of such elements, thereby directing the elements toward target positions. The invention includes step-wise computer-assisted image analysis methodology in an image analysis system linked to a computer program containing system logic, to identify problem areas of the work pieces, and to provide step-wise implementation methodology which can be implemented automatically but is sometimes implemented through human intervention, for making appropriate adjustments to the process. The invention further comprehends apparatus for implementing the above methods, including machines arrayed in a manufacturing line, control apparatus effective to control cross-direction positioning of work pieces, an image collecting system, a memory system, and an image analysis system.

Claims

1. A method of controlling cross-machine direction alignment of elements being assembled as work nieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the work pieces as the work nieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the work pieces;

(d) moving work pieces from work station to work station, and establishing the element on the respective work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, alone the manufacturing line path such that the work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

wherein the reference path represents a centerline of the manufacturing line.

2. A method as in claim 1, the center line of the manufacturing line corresponding with center lines of the products as the products are being fabricated on the manufacturing line.

3. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the work pieces;

(d) moving work pieces from work station to work station, and establishing the element on the respective work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

the evaluating of step (h) comprising direct human intervention in determining at least one measurement.

4. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective products from the respectively work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the work pieces;

(d) moving work pieces from work station to work station, and establishing the element on the respective work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

including capturing full digitized visual images of the respective work pieces,

the visual image inspection and control system providing a visual display of respective ones of the work pieces, and providing visual cues identifying elements that are outside acceptable ranges for the respective parameters.

5. A method as in claim 4, including establishing an acceptable range of cross-machine direction positions, relative to the reference path, for each of a plurality of elements, each to be established on each of the work pieces, and including taking effective action to prevent defective product from being shipped when the position of a respective element is inconsistent with the respective acceptable range.

6. A method as in claim 5 wherein the effective action comprises separating defective product from acceptable product by the time the defective product reaches the end of the manufacturing line.

7. A method as in claim 5 wherein the effective action comprises providing an alerting signal to an operator.

8. A method as in claim 5 wherein the effective action comprises adjusting cross-machine direction positioning of such elements on subsequent work pieces, to direct the elements toward target cross-machine direction positions, while providing an alerting signal to an operator and/or separating defective product from acceptable product by the time the defective product reaches the end of the manufacturing line.

9. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the work pieces;

(d) moving work pieces from work station to work station, and establishing the element on the respective work pieces at respective work stations;

(e) fixedly mounting a camera as a component of a vision imaging inspection and control system, along the manufacturing line path such that the work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

including storing, in permanent memory, full digitized visual image representation of selected ones of the work pieces, retrieving from permanent storage a full digitized visual image representation of one of the stored full digitized visual images, and conducting off-line image analysis of the retrieved image,

including implementing a computer-assisted image analysis methodology to assist a system operator in analyzing cross-machine direction positioning of respective elements of the work piece,

including implementing step-wise computer analysis methodology to assist the system operator in making adjustments to direct the process toward alignment of the respective elements along the reference path.

10. A method as in claim 9, including activating stepwise computer directed implementation methodology and thereby making appropriate adjustments to the process to thereby direct the elements along the reference path.

11. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line the manufacturing line including a plurality of work stations, to fabricate respective products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the work pieces;

(d) moving work pieces from work station to work station, and establishing the element on the respective work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

including storing in permanent memory, full digitized visual images of selected ones of the work pieces, retrieving from permanent storage a full digitized visual image representation of one of the stored full digitized visual images, and conducting off-line image analysis of the retrieved image,

including implementing a computer-assisted image analysis methodology to assist a system operator in analyzing cross-machine direction positioning of respective elements of the work piece,

including implementing an image analysis system linked to a computer program containing system logic effective to identify problem areas of the work piece and to then provide step-wise implementation methodology for making appropriate adjustments to the process, to thereby direct the elements along the reference path consistent with acceptable cross-direction positioning of the respective elements.

12. A method as in claim 11, wherein the system logic assists the operator in making appropriate adjustment decisions to thereby direct the elements for suitable cross-direction alignment along the reference path.

13. A method as in claim 12, including the system logic directing operator interaction with the visual image, the operator thus using computer tools to establish a measurement on the visual image, the system logic then applying the so-established measurement by calculating adjustments to be made to the process, and advising the operator regarding the calculated adjustments, the operator then making appropriate adjustments to the process to direct respective elements suitable for alignment along the reference path.

14. A method as in claim 13, the operator and the system logic working together to make the ultimate decision regarding which adjustments are to be made, and directing such adjustments to the manufacturing operation.

15. A method as in claim 11, including the system logic directing operator interaction with the visual image, the operator thus using computer tools to establish a measurement on the visual image, the system logic then applying the so-established measurement by calculating adjustments to be made to the process, and implementing the adjustments at respective locations on the manufacturing line, to make appropriate adjustments to the process to direct the respective elements for alignment along the reference path.

16. A method as in claim 15, including the system logic directing sequential steps of operator interaction with the visual image such that the operator makes, and correspondingly identifies to the system logic, a controlled sequence of measurements on the visual image.

17. A method as in claim 16, including, based on the controlled sequence of measurements, the system logic subsequently calculating adjustments to be made in the manufacturing operation, and the locations of such adjustments on the manufacturing line.

18. A method as in claimed the operator and the system logic working together to make the ultimate decision regarding which adjustments are to be made, and directing such adjustments to the manufacturing operation.

19. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the work pieces;

(d) moving work pieces from work station to work station, and establishing the element on the respective work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

the camera being mounted at a first work station, and including fixedly mounting a second camera at a second work station, and capturing second visual images of the respective work pieces moving past the second camera, and using the composite of the first and second visual images to evaluate cross-machine direction positioning of the respective elements with respect to the reference path.

20. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective absorbent article products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the absorbent article work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established an respective ones of the absorbent article work pieces;

(d) moving absorbent article work pieces from work station to work station, and establishing the element on of the respective absorbent article work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the absorbent article work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective absorbent article work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective absorbent article work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

wherein the reference path represents a centerline of the manufacturing line.

21. A method as in claim 20, the center line of the manufacturing line corresponding with center lines of the absorbent article products being fabricated on the manufacturing line.

22. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective absorbent article products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the absorbent article work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions alone the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the absorbent article work pieces;

(d) moving absorbent article work pieces from work station to work station, and establishing the element on of the respective absorbent article work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the absorbent article work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective absorbent article work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective absorbent article work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

the evaluating of step (h) comprising direct human intervention in determining at least one measurement.

23. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective absorbent article products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the absorbent article work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions alone the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the absorbent article work pieces;

(d) moving absorbent article work pieces from work station to work station, and establishing the element on of the respective absorbent article work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the absorbent article work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective absorbent article work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective absorbent article work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

including capturing full digitized visual images of the respective work pieces,

the visual image inspection and control system providing a visual display of respective ones of the work pieces, and providing visual cues identifying elements that are outside acceptable ranges for the respective parameters.

24. A method as in claim, including establishing an acceptable range of cross-machine direction positions, relative to the reference path, for each of a plurality of elements, each to be established on each of the work pieces, and including taking effective action to prevent defective product from being shipped when the position of a respective element is inconsistent with respective acceptable range.

25. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective absorbent article products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the absorbent article work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the absorbent article work pieces;

(d) moving absorbent article work pieces from work station to work station, and establishing the element on of the respective absorbent article work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the absorbent article work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective absorbent article work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective absorbent article work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

including storing, in permanent memory, full digitized visual images of selected ones of the work pieces, retrieving from permanent storage a full digitized visual image representation of one of the stored full digitized visual images, and conducting off-line image analysis of the retrieved image,

including implementing a computer-assisted image analysis methodology to assist a system operator in analyzing cross-machine direction positioning of respective elements of the work piece,

including implementing step-wise computer analysis methodology to assist the system operator in making adjustments to direct the process toward alignment of the respective elements along the reference path.

26. A method as in claim 25, including activating step wise computer directed implementation methodology and thereby making appropriate adjustments to the process to thereby direct the elements along the reference path.

27. A method of controlling cross-machine direction alignment of elements being assembled as work pieces on a manufacturing line, the manufacturing line including a plurality of work stations, to fabricate respective absorbent article products from the respective work pieces, the method comprising:

(a) defining a machine direction manufacturing line path traversed by the absorbent article work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) defining a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines alone the manufacturing line;

(c) establishing acceptable cross-machine direction positions along the manufacturing line path and relative to the reference path, for an element to be established on respective ones of the absorbent article work pieces;

(d) moving absorbent article work pieces from work station to work station, and establishing the element on of the respective absorbent article work pieces at respective work stations;

(e) fixedly mounting a camera, as a component of a vision imaging inspection and control system, along the manufacturing line path such that the absorbent article work pieces move past the camera, the camera having an image window defined in terms of images to be captured by the camera and to be displayed by the imaging system;

(f) referencing the image window of the camera to the reference path;

(g) capturing visual images of respective absorbent article work pieces moving past the camera; and

(h) in the captured visual images, evaluating the cross-machine direction position of the element on the respective absorbent article work pieces with respect to the reference path, against the established acceptable cross-machine direction positions,

including storing, in permanent memory, full digitized visual images of selected ones of the work pieces, retrieving from permanent storage a full digitized visual image representation of one of the stored full digitized visual images, and conducting off-line image analysis of the retrieved image,

including implementing a computer-assisted image analysis methodology to assist a system operator in analyzing cross-machine direction positioning of respective elements of the work piece,

including implementing an image analysis system linked to a computer program containing system logic effective to identify problem areas of the work piece and to then provide step-wise implementation methodology for making appropriate adjustments to the process, to thereby direct the elements along the reference path consistent with acceptable cross-direction positioning of the respective elements.

28. A method as in claim 27 wherein the system logic assists the operator in making appropriate adjustment decisions to thereby direct the elements for suitable cross-direction alignment along the reference path.

29. A method as in claim 28, including the system logic directing operator interaction with the visual image, the operator thus using computer tools to establish a measurement on the visual image, the system logic then applying the so established measurement by calculating adjustments to be made to the process, and advising the operator regarding the calculated adjustments, the operator then making appropriate adjustments to the process to direct respective elements suitable for alignment along the reference path.

30. A method as in claim 29, the operator and the system logic working together to make the ultimate decision regarding which adjustments are to be made, and directing such adjustments to the manufacturing operation.

31. A method as in claim 27, including the system logic directing operator interaction with the visual image, the operator thus using computer tools to establish a measurement on the visual image, the system logic then applying the so-established measurement by calculating adjustments to be made to the process, and implementing the adjustments at respective locations or the manufacturing line, to make appropriate adjustments to the process to direct the respective elements for alignment along the reference path.

32. A method as in claim 31, including the system logic directing sequential steps of operator interaction with the visual image such that the operator makes, and correspondingly identifies to the system logic, a controlled sequence of measurements on the visual image and, based on the controlled sequence of measurements, the system logic subsequently calculating adjustments to be made in the manufacturing operation, and the locations of such adjustments on the manufacturing line.

33. Apparatus for controlling cross-machine direction alignment of a web suitable for use in fabricating absorbent articles, and with which web elements are being assembled to form work pieces on a manufacturing line, using a manufacturing process, the manufacturing line including a plurality of work stations to fabricate respective products from the respective work pieces, said apparatus comprising:

(a) apparatus defining a machine direction manufacturing line path traversed by the work pieces as the work pieces move from work station to work station and have work performed thereon;

(b) sensing apparatus for sensing transverse direction positioning, with respect to the reference path, of the web or an element to be established on the web at respective ones of the work pieces;

(c) web guide apparatus for controlling transverse direction positioning, with respect to the reference path, of the web or an element to be established on the web at respective ones of the work pieces; and

(d) process control apparatus having a memory, and defining, in such memory, a machine direction reference path extending in the direction of the machine direction manufacturing line path and referenced to machines along the manufacturing line, and establishing acceptable cross-machine direction positions, relative to the reference path, for the web or an element to be established on the web at respective ones of the work pieces.