Proactive control of a process after the beginning of a destabilizing event

• US 6,553,270 B1
• Filed: 06/30/1999
• Issued: 04/22/2003
• Est. Priority Date: 06/30/1999
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Norman, Andrew, Houle, Alain Christian, Pennings, Michael Earl, Hein, John Gerard, Lashbrook, Glen Everett
• Primary Examiner(s): Starks, Jr., Wilbert L.
• Assistant Examiner(s): BARNES-BULLOCK, CRYSTAL JOY
• Application Number:
  US09/345,037
• Time in Patent Office: 1,392 Days
• Field of Search: 700/30-32, 700/54, 700/71, 700/110, 700/124, 700/129, 700/57, 702/86, 702/179, 702/183, 702/180
• US Class Current: 700/54
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 2219/34355 List of failure events, list of actions, events, trigger actions
• CPC Class Codes: G05B 2219/50059 Record profile error, used for next machining pass
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Apparatus and methods controlling a process producing segments of product wherein a destabilizing event of a particular type periodically destabilizes the process, resulting in product or process deviation from a target parameter associated with a number of segments of the product, from segment number 1 to segment number n. The method associates, with respective ones of the n units of product, deviation amounts corresponding to historical deviation amounts for the respective so-numbered units of product in past occurrences of the particular type destabilizing event, and applying to selected ones of the n segments of product correction factors derived from respective associated historical deviation amounts for the respective units of product, thereby making pro-active adjustments to respective ones of the n units of product, upon occurrence of the destabilizing event. Preferred methods include applying the correction factors to each of the n units of product. Preferred correction factors are registration factors. In preferred sets of adjustment instructions, at least some of the adjustment instructions include elements derived from vertical analysis and from horizontal analysis, of deviation data. The method is preferably applied to manufacturing processes producing discrete units of absorbent article product for personal care use in absorbing body exudates. The invention contemplates combining and/or modifying up to 10, in some cases up to 20 or more deviation profiles, and thereby obtaining a representative composite correction profile up-date element, before updating the correction profile.

Claims

1. A method of controlling a process producing units of product and wherein a destabilizing event of a particular type periodically destabilizes the process, resulting in a deviation from a target parameter in a number of units of the product, from unit number 1 to unit number n, the method comprising:

(a) upon occurrence of the particular type of destabilizing event, by vertical analysis, associating with respective ones of the n units of product, deviation amounts corresponding to historical deviation amounts for the respective so-numbered units of product in past occurrences of the particular type of destabilizing event; and

(b) applying to selected nth ones of the n units of product, correction factors, based on vertical analysis and derived from respective associated historical deviation amounts for the respective nth units of product,

thereby making pro-active adjustments to respective ones of the n units of product, upon occurrence of the destabilizing event.

2. A method as in claim 1, including applying the correction factors to each of the n units of product.

3. A method as in claim 1, including applying the correction factors as registration correction factors, to with machine direction registration.

4. A method as in claim 1, including applying the correction factors as registration correction factors, to cross machine direction registration.

5. A method as in claim 1, including, using a computing controller, computing correction factors for selected units, using historical operating data from at least two previous occurrences of the destabilizing event and respectively developing a correction profile using the combination of the correction factors, for use upon occurrence of a future destabilizing event.

6. A method as in claim 5, including

collecting and recording data for respective ones of the subsequent n units of product, and thereby obtaining fresh deviation data on multiple units of product, up to n units, for the destabilizing event, thus obtaining samples for up to n units of product,

for respective ones of the n units of product, using the computing controller, automatically in real time computing a representative deviation based on the sample obtained for the respective nth unit of product, and thereby obtaining a deviation profile representative of the respective units of product associated with the respective destabilizing event,

combining and/or modifying up to 10 of the deviation profiles, and thereby obtaining a representative composite correction profile up-date element for such type destabilizing event,

upon obtaining the correction profile up-date element, adding the so-obtained correction profile up-date element to the correction profile, thus to obtain an up-dated correction profile, and

applying the up-dated correction profile to a subsequent occurrence of the respective type destabilizing event.

7. A method as in claim 6, including beginning to add the so-obtained correction profile update element to the correction profile no later than the n+10th unit of the last destabilizing event from which the correction profile element data was derived.

8. A method as in claim 5, including computing separate and distinct correction factors for selected units to which such registration correction factor is applied, including deriving each such correction factor from the same numbered nth unit in the previous destabilizing event or events, whereby each such correction factor is based on data derived from the respective nth unit of product past the destabilizing event, in such previous destabilizing event or events.

9. A method as in claim 5, including, using a computing controller, computing correction factors for units evenly spaced in terms of unit number, using historical operating data from at least two previous occurrences of the destabilizing event and respectively developing a correction profile using the combination of the correction factors, for use upon occurrence of a future destabilizing event.

10. A method as in claim 5, including, using a computing controller, computing correction factors for each unit, using historical operating data from at least two previous occurrences of the stabilizing event and respectively developing a correction profile using the combination of the correction factors, for use upon occurrence of a future destabilizing event.

11. A method as in claim 5, including

collecting and recording registration data for respective ones of the subsequent n units of product, and thereby obtaining fresh registration deviation data on multiple units of product, up to n units, for the destabilizing event, thus obtaining samples for up to n units of product,

for respective ones of the n units of product, using the computing controller, automatically in real time computing a representative registration deviation based on the sample obtained for the respective nth unit of product, and thereby obtaining a registration deviation profile representative of the respective units of product associated with the respective destabilizing event,

combining and/or modifying the deviation profile, and thereby obtaining a representative correction profile up-date element for such type destabilizing event,

upon obtaining the correction profile up-date element, adding the so-obtained correction profile up-date element to the registration correction profile, no later than the 2 nth unit of the last destabilizing event from which the correction profile element data was derived, thus to obtain an up-dated registration correction profile, and

applying the up-dated registration correction profile to a subsequent occurrence of the respective type destabilizing event.

12. A method as in claim 5, including collecting deviation information from ones of the respective n units of product during subsequent occurrences of the destabilizing event and, based on the deviation information so collected, periodically making adjustments to the correction profile and applying the adjusted correction profile to ones of the respective n units of product at future occurrences of the destabilizing event.

13. A method as in claim 5, including

collecting and recording registration data for respective ones of the subsequent n units of product, and thereby obtaining fresh registration deviation data on multiple units of product, up to n units, for the destabilizing event, thus obtaining samples for up to n units of product,

for respective ones of the n units of product, using the computing controller, automatically in real time computing a representative registration deviation based on the sample obtained for the respective nth unit of product, and thereby obtaining a registration deviation profile representative of the respective units of product associated with the respective destabilizing event,

combining and/or modifying up to 20 of the deviation profiles, and thereby obtaining a representative composite correction profile up-date element for such type destabilizing event,

upon obtaining the correction profile up-date element, adding the so-obtained correction profile up-date element to the registration correction profile, thus to obtain an up-dated registration correction profile, and

applying the up-dated registration correction profile to a subsequent occurrence of the respective type destabilizing event.

14. A method as in claim 13, including beginning to add the so-obtained correction profile up-date element to the correction profile no later than the n+20th unit of the last destabilizing even from which the correction profile element data was derived.

15. A method as in claim 1, including, using a computing controller, computing correction factors for units evenly spaced in terms of unit number, using historical operating data from at least previous occurrences of the destabilizing event and respectively developing a correction profile using the combination of the correction factors, for use upon occurrence of a future destabilizing event.

16. A method as in claim 1, including, using a computing controller, computing correction factors for each unit, using historical operating data from at least two previous occurrences of the destabilizing event and respectively developing a correction profile using the combination of the correction factors, for use upon occurrence of a future destabilizing event.

17. A method as in claim 1, applied to a manufacturing process producing discrete units of absorbent articles for personal care use in absorbing body exudates.

18. A method of controlling a process producing discrete units of absorbent article product for personal care use and wherein a destabilizing event of a particular type periodically destabilizes the process, resulting in a deviation from a target parameter in a number of units of the product, from unit number 1 to unit number n, the method comprising:

(a) operating the process, including continuing to operate the process upon occurrence of such type destabilizing events, x times, x being greater than 1, and upon occurrence of such destabilizing events, collecting and recording product data for respective ones of the subsequent n units of product, and thereby obtaining product deviation information on multiple units of product, up to n units of product, for each of the x such destabilizing events, thus obtaining up to x samples for each of the n units of product;

(b) for respective ones of the n units of product, computing a representative product deviation based on the samples obtained for the respective nth unit of product, from the x such destabilizing events, and thereby obtaining a product deviation profile representative of the product deviations of the respective units of product from a target parameter, and obtained from the x destabilizing events;

(c) modifying the deviation profile, and thereby obtaining a product correction profile element for such type destabilizing event, the correction profile including a correction for each of the n units of product for which a product deviation indication was obtained, specific to historical deviations of that nth unit of product;

(d) adding the so-obtained product correction profile to any pre-existing product correction profile used in collecting the sample, thus to obtain an up-dated product correction profile; and

(e) applying the up-dated product correction profile to a subsequent occurrence of the respective type destabilizing event.

19. A method as in claim 18 including, while applying the up-dated product correction profile to a subsequent such destabilizing event, collecting product deviation data for up to respective n units of product, and using the so-collected deviation data to further up-date the product correction profile.

20. A method as in claim 18, the computing of the product deviations comprising averaging the deviations recorded for the respective nth units of product.

21. A method as in claim 18, including collecting product deviation information from ones of the respective n units of product during subsequent occurrences of the destabilizing event, and periodically making adjustments to the product correction profile based on the product deviation information so collected.

22. A method as in claim 18, including applying the product correction profile to each of the n units of product.

23. A method as in claim 18 wherein the product deviation is registration and the product correction profile is a registration correction profile.

24. A method as in claim 23, including applying the registration correction profile to with machine direction registration.

25. A method as in claim 23, including applying the registration correction profile to cross machine direction registration.

26. A method of controlling a process producing product in discrete product segments, the method comprising:

(a) operating the process, including continuing to operate the process upon occurrence of a destabilizing event, and collecting and recording process performance data for respective ones of the subsequent n units of product, and thereby obtaining process performance deviation information on multiple units of product, up to n units of product, for such destabilizing event, thus obtaining samples of the performance data for up to the n units of product;

(b) for respective ones of the n units of product, computing a representative performance deviation based on the sample obtained for the respective unit of product, and thereby obtaining a process performance deviation profile representative of the respective units of product which are produced proximate the destabilizing event;

(c) modifying the deviation profile, and thereby obtaining a process performance correction profile element for the destabilizing event, including correction specifically directed to each of the n units of product for which a process performance deviation indication was obtained, specific to historical deviations of that nth unit of product based on vertical analysis;

(d) incorporating the so-obtained performance correction profile element into any pre-existing correction profile used in collecting the samples and based on vertical analysis, thus to obtain an up-dated performance correction profile based on vertical analysis; and

(e) applying the up-dated performance correction profile to a subsequent occurrence of respective type destabilizing event wherein each correction profile data point is based on the nth unit of product in a plurality of historical destabilizing events of the respective type.

27. A method as in claim 26, including applying the performance correction profile to each of the n units product.

28. A method as in claim 26, including applying the performance correction profile to with machine direction registration.

29. A method as in claim 26, including applying the performance correction profile to cross machine direction registration.

30. Apparatus for controlling a process producing segments of product and wherein a destabilizing event of a particular type periodically destabilizes the process, resulting in a deviation from a target parameter in a number of segments of the product, from segment number 1 to segment number n, said apparatus comprising:

(a) a manufacturing line comprising a plurality of machines manufacturing the product;

(b) a computing controller effective, upon occurrence of the particular type of destabilizing event, to associate with respective ones of the n segments of product, deviation amounts corresponding to historical deviation amounts for the respective so-numbered segments of product of segment number 1 to segment number n, according to vertical analysis, in past occurrences of the particular type of destabilizing event, and to apply to respective nth ones of the n segments of product, correction factors derived from respective associated historical deviation amounts for the respective nth segments of product at least in part in accord with such vertical analysis;

(c) one or more detection devices detecting one or more parameters with respect to the process or product being produced by the process; and

(d) one or more actuation devices effecting adjustments to the machines in response to the correction factors developed from deviation amounts detected in one or more previous destabilizing events, thereby to make pro-active adjustments to respective ones of the n segments of product, upon occurrence of the destabilizing event, based on vertical analysis of the n segments of product.