Monitoring system for web breaks in a paper machine

• US 6,463,170 B1
• Filed: 04/12/1999
• Issued: 10/08/2002
• Est. Priority Date: 02/25/1999
• Status: Expired due to Term

• Current Assignee: Honeywell Oy (Honeywell International Inc.)
• Original Assignee: Honeywell Oy (Honeywell International Inc.)
• Inventors: Valkonen, Mika, Snellman, Jorma, Toivonen, Juha
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): PATEL, KANJIBHAI B
• Application Number:
  US09/289,903
• Time in Patent Office: 1,275 Days
• Field of Search: 382/141, 382/148, 382/255, 382/181, 382/190, 382/216, 382/218, 382/254, 382/282, 382/305, 348/88, 348/86, 348/92, 348/240, 226/11, 226/17, 226/92, 356/430, 356/431, 356/429, 345/700
• US Class Current: 382/141
• CPC Class Codes: D21F 7/04 Paper-break control devices
• CPC Class Codes: D21G 9/0009 Paper-making control systems
• CPC Class Codes: G01N 21/8903 using a multiple detector array
• CPC Class Codes: G01N 21/8915 non-woven textile material

Abstract

The invention relates to a monitoring system for web breaks in a paper machine. A web (W) is monitored by means of a number of cameras (1) and the image data of various camera positions is used for compiling focused image regions (12). Camera-specific image processing equipment (2, 12) is adapted to compile image change data by comparing the change between sequential images as far as the focused image region (12) is concerned. The image change data is compared with a normal level of image change and an alarm message (3a) is delivered if the image change level has a deviation from the reference level which exceeds a preset threshold value. A break alarm is set off, in case said alarm message (3a) is delivered by image change data comparators (3) of one or more pre-selected camera positions (P1-Pn).

Claims

1. A monitoring system for web breaks in a paper machine, comprising:

a number of cameras for imaging various positions of a monitored web;

digital image processing equipment for storing image data from a plurality of camera positions; and

a selector for choosing a focused picture region from said image data of a selectable individual picture of various camera positions,

said digital image processing equipment is adapted to compile image change data by comparing the change between sequential images as far as said focused image region is concerned, and a reference level for said image change data, which represents a normal level of said image change data;

comparators for comparing said image change data to said reference level and for setting off an alarm message, in case said image change data has a deviation from said reference level which exceeds a preset threshold value; and

an alarm equipment for setting off a break alarm if said alarm message is delivered said image change data comparators of one or more camera positions.

2. A monitoring system as set forth in claim 1, further comprising a storage selector, which under the control of the alarm equipment for choosing those cameras which correspond to positions whose image data is stored in a break data bank in connection with a break alarm.

3. A monitoring system as set forth in claim 1 wherein the alarm equipment is adapted not to set off an alarm until the image change data deviation from the reference level in the focused image region for a number of positions exceeds said threshold value.

4. A monitoring system as set forth in claim 1, wherein the reference level is based on one or more of the following actions:

an automatic image analysis continuously or periodically for determining a normal image change level;

a user'"'"'s selection in connection with the selection or change of an image region producing the image change data;

the use of image change data, which dates further back than the actual, real-time image change data, as a reference level or as one parameter in establishing a reference level.

5. A monitoring system as set forth in claim 1, wherein the selection function for framing the focused image region relevant to the image change data, i.e., the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

6. A monitoring system as set forth in claim 2, wherein the alarm equipment is adapted not to set off an alarm until the image change data deviation from the reference level in a focused image region for a number of positions exceeds said threshold value.

7. A monitoring system as set forth in claim 2, wherein the reference level is based on one or more of the following actions:

an automatic image analysis continuously or periodically for determining a normal image change level,

a user'"'"'s selection in connection with the selection or change of an image region producing the image change data,

the use of image change data, which dates further back than the actual, real-time image change data, as a reference level or as one parameter in establishing a reference level.

8. A monitoring system as set forth in claim 3, wherein the reference level is based on one or more of the following actions:

an automatic image analysis continuously or periodically for determining a normal image change level,

a user'"'"'s selection in connection with the selection or change of an image region producing the image change data,

the use of image change data, which dates further back than the actual, real-time image change data, as a reference level or as one parameter in establishing a reference level.

9. A monitoring system as set forth in claim 6, wherein the reference level is based on one or more of the following actions:

an automatic image analysis continuously or periodically for determining a normal image change level

a user'"'"'s selection in connection with the selection or change of an image region producing the image change data

the use of image change data, which dates further back than the actual, real-time image change data, as a reference level or as one parameter in establishing a reference level.

10. A monitoring system as set forth in claim 2, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

11. A monitoring system as set forth in claim 3, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

12. A monitoring system as set forth in claim 6, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

13. A monitoring system as set forth in claim 4, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

14. A monitoring system as set forth in claim 7, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

15. A monitoring system as set forth in claim 8, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

16. A monitoring system as set forth in claim 9, wherein the selection function for framing the focused image region relevant to the image change data, i.e. the selection of a size and location for the focused image region, is controllable by means of tools included in a user'"'"'s computer and the control is applied to said digital image processing equipment.

17. A monitoring system for web breaks in a paper machine, comprising:

a number of cameras operative to produce pictures of a monitored web at a corresponding number of locations;

digital image processing equipment in communication with the number of cameras and operative to store image data of each of said pictures from said number of cameras;

a selector operative to select and image a focused picture region from said image data of a selectable picture;

said digital image processing equipment being operative to compile image change data by comparing sequential images of said focused picture region; and

a reference level for said image change data, which represents a normal level of said image change data;

at least one comparator operative to compare said image change data to said reference level and to set off an alarm message, in case said image change data has a deviation from said reference level which exceeds a preset threshold value; and

an alarm equipment operative to set off a break alarm if said alarm message has been set off by the at least one comparator.