Method for Monitoring the Quality Properties of a Cellulose Bale in a Bale Line

Abstract

A method for monitoring the quality characteristics of a pulp bale in a baling line of a pulp machine, wherein cut pulp sheets are stacked to form a pulp bale. Pictures of the pulp bale are taken with a camera system and are evaluated with a computer-implemented computational model for image analysis. Improved availability of the bale line is achieved.

Claims

1-9. (canceled)

10. A method for monitoring geometrical properties of a pulp bale (1) in a baling line of a pulp machine, comprising: cutting pulp sheets and stacking the cut sheets to form a pulp bale (1); taking images of the pulp bale (1) with a camera system; evaluating the images with a computer-implemented computational model for image analysis, wherein the computer model identifies geometric elements of the pulp bale (1) on the images, the elements selected from a group consisting of corners, edges (3), surfaces (2) and volume of the pulp bale, and the computer model assesses the geometric properties of the pulp bale (1) from the identified geometric elements of the pulp bale (1), and wherein the computational model is trained with a training data set comprising training images of pulp bales (1), and for the individual training images, the identified geometric elements of the pulp bale (1) and the assessment of the geometric properties of the pulp bale (1).

11. The method according to claim 10, comprising moving the pulp bale (1) to a defined position relative to the camera system, and using the camera system to take images of the pulp bale (1) in the defined position.

12. The method according to claim 11, comprising using a light source to illuminate the pulp bale (1), wherein the camera system takes images of the illuminated pulp bale (1).

13. The method according to claim 10, comprising using a light source to illuminate the pulp bale (1), and using the camera system to take images of the illuminated pulp bale (1).

14. The method according to claim 10, comprising projecting a line (4) onto a surface (2) of the pulp bale (1) using a light source, wherein the calculation model assesses the stacking accuracy of the pulp bale (1) or the cutting quality of the individual sheets from a distortion of the line (4) on the surface (2) of the pulp bale (1).

15. The method according to claim 14, wherein the light source is a line laser.

16. The method according to claim 11, comprising projecting a line (4) onto a surface (2) of the pulp bale (1) using a light source, wherein the calculation model assesses the stacking accuracy of the pulp bale (1) or the cutting quality of the individual sheets from a distortion of the line (4) on the surface (2) of the pulp bale (1).

17. The method according to claim 13, comprising projecting a line (4) onto a surface (2) of the pulp bale (1) using a light source, wherein the calculation model assesses the stacking accuracy of the pulp bale (1) or the cutting quality of the individual sheets from a distortion of the line (4) on the surface (2) of the pulp bale (1).

18. The method according to claim 10, comprising unpacking the pulp bale (1) and using the computational model to assess one or more of the cut quality of the pulp sheets, shape of the pulp sheets, squareness of the pulp sheets and stacking accuracy of the pulp bale (1).

19. The method according to claim 11, comprising unpacking the pulp bale (1) and using the computational model to assess one or more of the cut quality of the pulp sheets, shape of the pulp sheets, squareness of the pulp sheets and stacking accuracy of the pulp bale (1).

20. The method according to claim 13, comprising unpacking the pulp bale (1) and using the computational model to assess one or more of the cut quality of the pulp sheets, shape of the pulp sheets, squareness of the pulp sheets and stacking accuracy of the pulp bale (1).

21. The method according to claim 14, comprising unpacking the pulp bale (1) and using the computational model to assess one or more of the cut quality of the pulp sheets, shape of the pulp sheets, squareness of the pulp sheets and stacking accuracy of the pulp bale (1).

22. The method according to claim 10, comprising making images of the pulp bale (1) with the camera system, wrapping the pulp bale (1) to make a package, and using the computational model to assess one or more of the condition, folding, tying, and printing of the package.

23. The method according to claim 11, comprising making images of the pulp bale (1) with the camera system, wrapping the pulp bale (1) to make a package, and using the computational model to assess one or more of the condition, folding, tying, and printing of the package.

24. The method according to claim 13, comprising making images of the pulp bale (1) with the camera system, wrapping the pulp bale (1) to make a package, and using the computational model to assess one or more of the condition, folding, tying, and printing of the package.

25. The method according to claim 10, comprising calibrating the computational model with a calibration data set comprising calibration images of pulp bales (1), and for the individual calibration images, a quantification of the geometric elements of the pulp bale (1).

26. The method according to claim 25, wherein the geometric elements of the pulp bale (1) are selected from one or more of length of an edge (3), area (2) of the pulp bale (1), and volume of the pulp bale (1).

27. A baling line of a pulp machine, comprising a camera system; and means for performing the method according to claim 10.

28. The baling line of claim 27, wherein the means for performing the method according to claim 10 is a computer program and hardware.

29. A computer program product, comprising: instructions for causing a baling line of a pulp machine having a camera system to perform the method steps of claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The invention will now be described using the examples in the drawings.

[0022] FIG. 1 shows a pulp bale in a baling line.

[0023] FIG. 2 shows a pulp bale with surfaces as identified by the computational model.

[0024] FIG. 3 shows a pulp bale with edges as identified by the computational model.

DETAILED DESCRIPTION

[0025] FIG. 1 shows an unwrapped pulp bale 1 stacked from cut pulp sheets in a baling line. The human eye can easily identify the geometric elements of the pulp bale 1, for example individual faces 2, or edges 3. According to the relative arrangement of the pulp bale 1 to the imaging camera system, three surfaces of the pulp bale are visible. With the herein described computer-implemented computational model for image analysis, the image reproduced in FIG. 1 can be evaluated. In doing so, the calculation model identifies geometric elements of the pulp bale 1 on the image, such as corners, edges 3, areas 2, volume, shape of the pulp bale, and assesses the quality characteristics of the pulp bale 1, such as the cut quality of the pulp sheets as well as the shape, squareness or stacking accuracy, based on the identified geometric elements of the unpacked pulp bale 1. FIG. 1 also shows a line 4 projected onto a surface of the pulp bale 1, wherein in this optional process step, a light source for projecting a line, in particular a coherent light source, e.g. a line laser, is used to project the line 4 onto the surface 2 of the pulp bale 1. This optional process step allows in particular an advantageous assessment of the stacking accuracy or the cutting quality of the individual sheets on the basis of the distortion of the line 4 on the surface 2 of the pulp bale 1.

[0026] FIG. 2 shows an unpacked pulp bale 1 and the hatched areas 2 identified by the computational model with corners shown as spheres. The edges 3 as delimitation of neighbouring surfaces to each other were thus also identified by the calculation model. FIG. 3 accordingly shows the pulp bale 1 and the edges 3 identified by the calculation model and shown in dashed lines, whereby an ideal pulp bale is indicated analogous to a cube or cuboid. The calculation model thus allows monitoring of the quality characteristics, in particular the geometric properties, such as the shape or squareness, of the pulp bale 1. For example, from the shape of the edges identified by the computational model, the computational model can further assess the cut quality of the pulp sheets and the stacking accuracy of the pulp bale. By optionally using a light source to project a line onto a side surface of the pulp bale, a more accurate assessment of various quality characteristics of the pulp bale 1, such as stacking accuracy or cut quality, is possible based on the assessment of the distortion of the projected line.

[0027] The disclosed embodiments offer numerous advantages. They provide an increase in the efficiency or availability of the baling line through continuous, automated monitoring of the quality characteristics of the pulp bales. The quality of the pulp bales is monitored objectively and reproducibly, whereby pulp bales of insufficient quality, which for example have insufficient geometric properties, in particular an insufficient shape, can be ejected from the baling line at an early stage without causing problems in subsequent process steps. Conclusions can be drawn about the condition or monitoring of the condition of the cutting edges used in the longitudinal or transverse cutters.

REFERENCE NUMERALS

[0028] (1) Pulp bale [0029] (2) Surface [0030] (3) Edge [0031] (4) Line