Method and device

Abstract

The invention relates to a method and a device for adjusting a roller, the roller having a built-in element which is arranged in the interior of the roller and is rotatably mounted. The method comprises the following steps: a. recording a first image of the exterior of the roller from an analysis position and transmitting the recording to a calculation unit; b. determining the actual value of the angle of rotation ω by which the built-in element is rotated relative to a reference system by means of the calculation unit by image analysis of the first image and / or by the acquisition of values from an embedded sensor system; c. recording a second image of the exterior of the roller from a working position and transmitting the recording to a calculation unit; d. determining the reference system by image analysis of the second image and / or by the acquisition of values from the embedded sensor system; e. determining the actual position of the built-in element on the basis of the reference system and the actual value of the angle of rotation ω; f. displaying the determined actual position of the built-in element by superimposing a representation of the built-in element on the second image on a display.

Description

[0001] File: 28400 WO / PFW

[0002] - 1 -

[0003] Method and apparatus

[0004] The invention relates to a method for adjusting a roller and a device for carrying out such a method.

[0005] Various types of rollers are frequently used in industrial processes. A very specific class of rollers are suction rollers.

[0006] Suction rollers are perforated rollers with regions on their surface where a vacuum is created to retain water or to redirect the paper web. These regions are called "suction zones." The suction zones of a suction roller are separated by sealing strips located beneath the roller shell. A lubricating film of water forms between the sealing strips and the roller shell, sealing the suction zones.

[0007] A special type of suction roller is the suction press roller. These suction rollers, together with a counter element, usually a counter roller, form a press nip for pressing and dewatering the fiber web.

[0008] If, instead of a vacuum, a positive pressure is created inside the roller, it is called a "blow roller". For the sake of readability, the following will always refer to suction rollers, but this term also includes the corresponding blow rollers.

[0009] Such suction rollers, as well as adjustable sealing strips and format limiters, are described, for example, in documents DE 10 2009 000 371 or EP2707544 B1.

[0010] The position of the sealing strips, and therefore the positioning of the vacuum zone, is very important. It is usually desirable to have the vacuum zone in only one file: 28400 WO / PFW

[0011] - 2 -

[0012] to have an area in which the suction roller is enclosed by the paper web or a covering.

[0013] For example, with suction press rollers, incorrect positioning of the suction box can result in a dry content of the fiber web that is 1-2 percentage points lower than with optimal positioning, which represents a massive loss of efficiency for the press.

[0014] Nowadays, the adjustment of the suction box is mostly done manually while the machine is running and visually assessed:

[0015] • The suction box is rotated on the driver's side using markings (indicating the position of the sealing strips) until the position is approximately correct.

[0016] • The quality of the setting is inferred from indirect observations, such as the spray of nip drainage.

[0017] In order to ensure a reliable and reproducible positioning of installation elements such as suction boxes or sealing strips, the applicant proposes a method in DE102021104870 A1 in which the position of the installation element is determined by means of an image evaluation of the roller exterior, and is then represented as a superimposition of the image taken.

[0018] This use of “Augmented Reality” (AR) allows the operator for the first time to determine and optimize the position of, for example, the suction box relative to the paper web or the covering.

[0019] The only disadvantage of this AR method is that the user must always take a picture from which the position of the suction box can be determined. As a rule, the image must capture the operator-side end face of the roller. In practice, it has been shown that from positions where this end face can be clearly seen, the accuracy of the adjustment is often not optimally assessed. File: 28400 WO / PFW

[0020] - 3 -

[0021] The object of the invention is to further develop this method so that the user can optimally assess the quality of the setting. In particular, the invention is intended to give the user a great deal of freedom in choosing the position from which to view the roller in order to judge the suction box setting.

[0022] The problem is solved according to the invention by a method or a device according to the independent claims. Further advantageous embodiments of the present invention are found in the dependent claims.

[0023] A method is proposed for adjusting a roller, in particular a suction roller, for a machine for the production or processing of a fibrous web, wherein the roller has an installation element which is arranged inside the roller and is rotatably mounted.

[0024] The installation element can, for example, include or consist of a suction box and / or one or more sealing strips.

[0025] While the process is described using the example of suction or blow rollers, it can also be applied to other types of rollers. Alternative applications include shoe press rollers or bending compensation rollers, which incorporate a complex internal system of support and clamping elements that is not visible from the outside. Further applications are also conceivable.

[0026] The procedure comprises the following steps: a. Taking an initial image of the exterior of the roller from an analysis position and transmitting the image to a processing unit; b. Determining the actual value of the rotation angle w by which the component is rotated relative to a reference system using file: 28400 WO / PFW

[0027] - 4 -

[0028] a. Calculation unit through image analysis of the first image and / or by acquiring values ​​from embedded sensors. b. Capture of a second image of the outside of the roller from a working position and transmission of the image to a calculation unit. c. Determination of the reference system through image analysis of the second image and / or by acquiring values ​​from embedded sensors. d. Determination of the actual position of the component based on the reference system as well as the actual value of the rotation angle wf. Display of the determined actual position of the component by superimposing the second image with a representation of the component on a display.

[0029] The first and / or second image can be a still image or a video recording.

[0030] The recording can be done using the integrated camera of a mobile computing unit such as a smartphone, tablet, or similar device. In this case, the images are transmitted to the computing unit within the device. Image capture and image analysis can thus take place on the same device. The smartphone / tablet also provides the necessary display.

[0031] The actual position can then be displayed by overlaying the live image from the integrated camera.

[0032] Methods according to aspects of the present invention now enable the application to inspect the roller from any position, regardless of whether the exact location of the suction box or other internal components can be determined from that position. File: 28400 WO / PFW

[0033] - 5 -

[0034] The process is a two-stage procedure. In the first step, the position of the installation element is determined. This is essentially done as described in the prior art, in particular DE102021104870 A1. An initial image of the exterior of the roller is captured, and the position of the installation element is determined via image analysis or by acquiring sensor values. For this purpose, the user selects an analysis position such that the first image includes parts of the roller from which the position of the installation element can be determined. In a common case, this is the roller face on the operator side. The suction box position is usually adjusted from this point. However, other locations may be suitable for the first image in specific cases.

[0035] The mounting element is rotatably arranged within the roller. Its position within the roller can therefore be described by a rotation angle w. The actual value of this rotation angle w is determined relative to a reference system. This reference system can be determined either by a reference mark (e.g., a defined horizontal and / or vertical mark on a pillar) or, alternatively or additionally, by built-in sensors in the camera. When using smartphones or tablets, for example, the gravity sensors integrated into these devices can be used.

[0036] This knowledge of this angle w and the associated reference system is sufficient to determine the position of the installation element.

[0037] The user can now move to a largely freely selectable working position and take a second image. This working position can be different from the analysis position. It only needs to be ensured that the reference system can be determined based on this second image using image analysis or sensor data acquisition. This can again be achieved, in particular, by capturing reference markers and / or using the tablet's built-in sensors, etc. The actual value of the rotation angle w is then provided to the processing unit from the analysis of the first image. From file: 28400 WO / PFW

[0038] - 6 - With knowledge of the reference system and the actual value of the rotation angle, the calculation unit can now determine the actual position of the installation element relative to the current working position and overlay a representation of this installation element onto the second image on a display.

[0039] In addition to the freedom to choose the working position, separating the angle determination and the display of the installation element offers further advantages. For example, it is conceivable that the two steps could be performed by different users. The actual value of the rotation angle w can then be transferred to another calculation unit after it has been determined. If a user is currently in a working position, they do not need to move to an analysis position, but can instead assign another user to determine the angle w according to steps a. and b., and transfer it to the other calculation unit.

[0040] It is also conceivable that steps a. and b. are routinely carried out by a permanently installed camera surveillance system, which provides the actual value of the rotation angle w via network connections.

[0041] In advantageous embodiments of the method, a second working position or further working positions may also be provided, in which the position of the installation element can be displayed and inspected on the screen.

[0042] In particularly preferred embodiments of the method, at least one marker element can be provided which is attached or attachable at a defined position, wherein the marker element is automatically detected by means of image analysis and used to determine the rotation angle w and / or the reference system.

[0043] Such a marker element can be designed in such a way that it can be easily identified by image analysis based on its shape and / or color. File: 28400 WO / PFW

[0044] - 7 -

[0045] It is particularly advantageous if the marker element is designed in such a way that not only its general position can be recognized, but also its exact location in space, including any rotations.

[0046] This is particularly advantageous for methods according to aspects of the present invention. For example, such a marker element in the second image can be used to determine the reference system.

[0047] In particularly preferred embodiments of the method, marker elements can be provided at various positions in the vicinity of the roller. This allows any point from which such a marker element is visible to serve as a working position.

[0048] Since the operation of the paper machine causes the machine components and surrounding peripherals to become contaminated, permanently installed marker elements are often undesirable. A contaminated marker element may no longer be correctly detected by image analysis.

[0049] Therefore, it may be necessary to provide holding devices for a marker element at various positions around the roller. The marker element can then be inserted into the holding device as needed. When no further inspections are being carried out on the roller, the marker element can be removed again. This significantly reduces the marker element's susceptibility to contamination. The holding device and the marker element should be designed so that the marker element can only be inserted in a specific position. This ensures that the reference system is correctly determined. Furthermore, such temporary use of a marker element prevents it from disrupting the operation of the paper machine or work in the area at other times.

[0050] In another advantageous embodiment, prominent components or machine elements in the vicinity of the plant can also be selected as marker elements. Suitable file: 28400 WO / PFW

[0051] - 8 - are in particular components or machine elements whose known position is usually not changeable, and which can be easily identified by means of image recognition, e.g. due to their shape and / or color.

[0052] These can be characteristic measuring instruments such as pressure gauges, specific connection points, or similar. While such "predefined marker elements" carry the risk of being misaligned during maintenance, requiring readjustment of the reference system, they offer the advantage of routine cleaning during servicing, thus preventing issues with detection due to contamination.

[0053] Such predefined marker elements can be particularly advantageous for determining the reference system at the work position. In this way, many work positions can be easily achieved without the need for additional marker elements and holding devices.

[0054] Combinations are also possible where "predefined marker elements" are used in some locations. Additional marker elements or holding devices can then be attached at other desirable working positions from which no "predefined marker elements" are visible.

[0055] The positions where a marker element is placed are well-defined and known in advance. In particular, the position of the roller relative to these marker elements is also known. This improves the accuracy of the projection of the mounting element onto the image of the roller compared to designs where the roller's position is determined solely from the image of the roller.

[0056] Furthermore, a device for adjusting a roller, in particular a suction roller, for a machine for the production or processing of a fibrous web is proposed, which is arranged inside the roller and rotatable. File: 28400 WO / PFW

[0057] - 9 - is stored. The device comprises a mobile computing unit with a camera for capturing images and a display, wherein the mobile computing unit is configured to perform a method according to one aspect of the invention.

[0058] The mobile computing unit can be implemented in particular in the form of a smartphone, tablet or similar device, which has a camera and a display.

[0059] In particular, the device may additionally include at least one marker element that is automatically detectable by means of image analysis. Such a marker element may be designed so that it can be easily detected by image analysis due to its shape and / or color. The marker element may be configured so that it can be inserted into designated holding devices as needed.

[0060] The invention will be explained below with the aid of figures. The figures show, in detail:

[0061] Figures 1a and 1b show a suction roller which can be adjusted using a method according to aspects of the invention.

[0062] Figure 2 illustrates a detail of a method according to a further aspect of the invention.

[0063] The roller 1 of Figures 1a and 1b is a suction roller 1 and has a built-in element 2 in the form of a suction box 2. This suction box 2 extends over a large part of the axial length of the roller 1, but only over a comparatively small part of the circumference – usually less than 25% of the circumference of the roller 1. The suction box 2 is rotatably mounted about the axis of the roller 1. This allows adjustment of which area of ​​the roller circumference is suctioned by the suction box 2. File: 28400 WO / PFW

[0064] - 10 -

[0065] Both on the driver's side FS and on the drive side TS, the roller 1 has end caps 6a, 6b. The adjustment of the suction box 2, i.e., its rotation around the axis, is carried out here as usual from the driver's side FS.

[0066] During the transition from Figure 1a to Figure 1b, the suction box 2 was rotated clockwise by an angle co. During this adjustment, the cover 6a on the driver's side FS also rotates by this angle co, while the cover 6b on the drive side TS remains stationary.

[0067] If an observer is located at an analysis position 10, from which the cover 6a of the driver's side FS can be viewed, they can use a suitable device—for example, a smartphone 4—to take an initial image of the exterior of the roller. The smartphone 4 can then also serve as a processing unit 4 and determine the actual value of the rotation angle co by analyzing the initial image and / or by acquiring values ​​from embedded sensors. A marker element 3 is provided on the cover for more precise determination of the rotation angle co. By appropriately shaping and / or coloring the marker element 3, not only its position in space but also its corresponding rotation relative to a defined reference system can be reliably determined via image analysis. Such a reference system can be defined, for example, by the CD axis of the roller 1, the machine direction, and the perpendicular direction to it.The precise choice of the reference system is irrelevant for the procedures proposed here. It is only necessary that this reference system can be determined from a working position 20, from which, for example, there is no clear line of sight to the cover 3 of the driver's side FS. For this purpose, the user can take a second image of the outside of the roller 1 from a working position 20. The reference system can then be determined by image analysis of the second image and / or by acquiring values ​​from embedded sensors. As shown in Figures 1a and 1b, a marker element 3a is also provided on the cover 3a of the drive side TS for this purpose. The change in the marker position due to rotation cannot be determined here, since this cover 6b did not move when the mounting element 2 was adjusted. File: 28400 WO / PFW.

[0068] - 11 -

[0069] Marker element 3a is therefore not used to determine the actual value of the rotation angle co, but rather to determine the reference system. The actual value of the rotation angle co has already been determined through the analysis of the first image and is available to the calculation unit 5. Using this reference system, the information regarding the rotation angle co can then be transferred from the first image to the second image. Thus, even from working position 20, it is possible to display the actual position of the installation element 2 on a display 5 by superimposing 7 of the second image with a representation of the installation element 2, even though the current position of the installation element 2 cannot be determined from this working position 20.

[0070] As described, the marker element 3, 3a can have a special shape and color that facilitates the detection of its position in space and its rotation relative to a reference system using image analysis. Such marker elements 3, 3a can often have a rather complex structure and also be quite large. If these marker elements 3, 3a are permanently installed, they may interfere with the operation of the system. Furthermore, there is a risk of contamination, which could lead to a dirty marker element 3, 3a no longer being reliably detected by the image analysis, or the angle and position being determined incorrectly. Therefore, it is usually advantageous to design the marker elements 3, 3a to be removable. Retaining devices are then provided at defined positions to accommodate a marker element 3, 3a, into which it can be inserted as needed.Another advantage of this design is that a separate marker element 3a is not required for each intended working position. Instead, the procedure can be carried out with a single marker element 3, 3a, which can then be inserted into the respective fixture as needed.

[0071] Figure 2 shows again, by way of example, how at a working position 20 on a display 5 – here the display 5 of a smartphone or tablet – the actual position of the installation element 2 can be displayed as a superimposition 7 of the second image with a representation of the installation element. The second image can be File: 28400 WO / PFW

[0072] - 12 - in particular, the live image provided by the built-in camera of the smartphone or tablet.

[0073] File: 28400 WO / PFW

[0074] - 13 -

[0075] Reference symbol list

[0076] 1 roller, suction roller

[0077] 2 Installation element, suction box

[0078] 3, 3a Marker element

[0079] 4 Calculation unit

[0080] 5 Display

[0081] 6a, lid

[0082] 6b Lid

[0083] 7 Overlay

[0084] 10 Analysis Position

[0085] 20 Working position co rotation angle

[0086] FS Driver's Side

[0087] TS drive side

Claims

File: 28400 WO / PFW - 14 - Patent claims 1. Method for adjusting a roller (1), in particular a suction roller (1), for a machine for producing or processing a fibrous web, wherein the roller (1) has an installation element (2) which is arranged inside the roller (1) and is rotatably mounted, the method comprising the steps: a. capturing a first image of the outside of the roller (1) from an analysis position (10) and transmitting the image to a processing unit (4); b. determining the actual value of the rotation angle co by which the installation element (2) is rotated relative to a reference system by means of the processing unit (4) by image analysis of the first image and / or by acquiring values ​​from embedded sensors; c. capturing a second image of the outside of the roller (1) from a working position (20) and transmitting the image to a processing unit (4); d.Determining the reference system by image analysis of the second image and / or by acquiring values ​​from embedded sensors. e. Determining the actual position of the installation element (2) based on the reference system and the actual value of the rotation angle co. f. Displaying the determined actual position of the installation element (1) by superimposing (7) the second image with a representation of the installation element (2) on a display (5). File: 28400 WO / PFW - 15 - 2. Method according to claim 1, characterized in that the installation element (2) comprises or consists of a suction box (2) and / or one or more sealing strips.

3. Method according to one of the preceding claims, characterized in that at least one marker element (3, 3a) is provided which is attached or attachable at a defined position, wherein the marker element (3, 3a) is automatically detected by means of image analysis and is used to determine the rotation angle w and / or the reference system.

4. Method according to one of the preceding claims, characterized in that the analysis position (10) and the working position (20) are different positions.

5. Device for adjusting a roller (1), in particular a suction roller (1), for a machine for the production or processing of a fibrous web, which is arranged inside the roller (1) and is rotatably mounted, comprising a mobile calculation unit (4) with a camera for taking pictures and a display (5) wherein the mobile computing unit is configured to perform a method according to any of the preceding claims 6. Device according to claim 5, wherein the device additionally comprises at least one marker element that is automatically detectable by means of image analysis.

Images