A detection and switching system for the scale lines of gypsum boards

Abstract

The present invention discloses a detection and switching system for the scale lines of gypsum boards, which includes a first roller printing group and a second roller printing group sequentially arranged on the conveying line of the facing paper, and is used to switch to the other roller printing group for continuous printing of scale lines when one of the roller printing groups fails; a detection module is arranged downstream of the two roller printing groups and is used to detect the printed image formed by the imprint of the roller printing group in use on the facing paper; the control system, based on the comparison result of the printed image captured by the detection module with the standard image and the currently used roller printing group, respectively selects different regulation methods to switch the roller printing group put into printing use based on the roller printing group object to be switched; the present invention realizes intelligent unmanned replacement of the roller printing group, automatically replaces the roller printing group put into printing use, ensures that the scale lines remain continuous, and there will be no intermittent line marks, thus not affecting the later gypsum board cutting work.

Description

Technical Field

[0001] The present invention relates to the technical field of printing technology for gypsum board facing paper, and specifically relates to a berth allocation method and system based on ship demand analysis. Background Art

[0002] During the production process of paper-faced gypsum board, it is necessary to use roller printing to print scale lines on the surface of the facing paper, which is convenient for cutting the gypsum board during decoration. However, since the rubber and scraper used for printing scale lines on the roller printing are consumable and vulnerable parts, after long-term use, the printing ink marks are likely to become lighter and lighter, affecting the recognition of the scale of the gypsum board. Therefore, most of the existing roller printing groups are two groups, one for standby and one for use, so that when the scale lines are not clearly printed, the use can be switched from one in-use roller printing group to another.

[0003] However, most of the existing inspections of gypsum board facing paper are manual inspections. When switching the roller groups, due to manual operations, the switching operations lack timeliness, resulting in intermittent scale lines on the gypsum board, or problems such as repeated printing and misaligned and double-imaged scale lines, generating a batch of unqualified boards. Summary of the Invention

[0004] The purpose of the present invention is to provide a berth allocation method and system based on ship demand analysis to solve the technical problems in the prior art that the switching operations lack timeliness, resulting in intermittent scale lines on the gypsum board, or repeated printing and misaligned and double-imaged scale lines.

[0005] To solve the above technical problems, the present invention specifically provides the following technical solutions:

[0006] A detection and switching system for gypsum board scale lines, comprising:

[0007] At least two roller printing groups, which are sequentially arranged on the conveying line of the facing paper, and are divided into a first roller printing group and a second roller printing group, and are used to switch to another roller printing group for continuous printing of scale lines when one of the roller printing groups fails;

[0008] A detection module, which is arranged downstream of the two roller printing groups and is used to detect the printing image formed by the imprints of the roller printing group in use on the facing paper;

[0009] A control system, which is electrically connected to the detection module and the roller printing groups respectively. The control system selects different regulation methods to switch the roller printing group put into printing use based on the comparison result of the printing image captured by the detection module with the standard image and the currently used roller printing group, respectively for the roller printing group object to be switched to.

[0010] As a preferred embodiment of the present invention, the second roll printing group is located between the first roll printing group and the detection module, and the first roll printing group and the second roll printing group can move along the conveying line of the facing paper, so that the distance between the first roll printing group and the detection module is always an integer multiple of the set scale line specification length, and the distance between the first roll printing group and the second roll printing group is always an integer multiple of the set scale line specification length.

[0011] As a preferred embodiment of the present invention, an image storage module is provided in the control system, and the image storage module is used to save the scale line standard diagrams of different product specifications;

[0012] The detection module includes a light source arranged below the facing paper and a camera arranged below the facing paper. The camera sends the captured printing image to the control system. The control system selects the matching rotation circumferences of the first roll printing group and the second roll printing group according to the set scale line specification length, and the control system uses an image processing system to compare the scale line standard diagram with the feature marks on the printing image. The control system replaces the roll printing group put into printing according to the comparison result.

[0013] As a preferred embodiment of the present invention, the control system determines the time point when the camera takes the first shot according to the transmission speed of the facing paper, the distance between the currently used roll printing group and the camera, and the time point when the roll printing group starts rolling;

[0014] And the control system determines the time interval between each shot of the camera according to the length between two feature marks in the printing image and the transmission speed of the facing paper.

[0015] As a preferred embodiment of the present invention, the control system uses an image processing system to select the feature marks in the scale line standard diagram and the printing image, and performs binarization processing on the feature marks;

[0016] Respectively obtain the pixel values of the feature marks on the scale line standard diagram and the printing image;

[0017] Calculate the pixel value difference between the feature marks on the scale line standard diagram and the printing image, and compare the pixel value difference with a preset threshold range;

[0018] When the pixel value difference exceeds the preset threshold range, the control system replaces the roll printing group put into printing. When the pixel value difference is within the preset threshold range, the control system keeps the currently used roll printing group unchanged.

[0019] As a preferred embodiment of the present invention, when the camera captures an image of the current printed scale line, and the control system keeps the currently used printing roller group in continuous operation according to the comparison result, the currently used printing roller group continues to perform the rolling printing operation;

[0020] When the camera captures an image of the current printed scale line, and the control system replaces the printing roller group in use according to the comparison result, it is divided into replacing from the first printing roller group to the second printing roller group, or replacing from the second printing roller group to the first printing roller group. The control system selects the control method according to the different replaced roller groups.

[0021] As a preferred embodiment of the present invention, when the control system replaces the printing roller group in use from the first printing roller group to the second printing roller group according to the comparison result, the control system controls the first printing roller group to immediately stop the rolling printing operation, and the control system determines the time point for the second printing roller group to be put into use according to the distance between the first printing roller group and the second printing roller group and the transmission speed of the facing paper. The second printing roller group starts the rolling printing operation according to the calculated time point;

[0022] When the control system replaces the printing roller group in use from the second printing roller group to the first printing roller group according to the comparison result, the first printing roller group and the second printing roller group are simultaneously put into the printing operation, and the second printing roller group stops the rolling printing operation after continuously rotating for an integer cycle.

[0023] As a preferred embodiment of the present invention, both the first printing roller group and the second printing roller group are provided with starting ends, and the initial states of the first printing roller group and the second printing roller group when they are put into the rolling printing operation are: the starting ends are facing the facing paper.

[0024] As a preferred embodiment of the present invention, both the first printing roller group and the second printing roller group include a driving roller arranged above the facing paper and a printing roller arranged below the facing paper. The same ends of the driving roller and the printing roller are respectively installed on a side vertical plate, and the driving roller and the printing roller are connected by a transmission belt, wherein;

[0025] The driving roller is fixedly installed on the side vertical plate, the printing roller is movably installed on the side vertical plate, and a vertical cutting groove is provided on the side vertical plate. The printing roller moves up and down along the vertical cutting groove. A tension roller is also provided between the driving roller and the printing roller, and the tension roller is used to always keep the transmission belt in a taut state when the distance between the driving roller and the printing roller changes.

[0026] As a preferred embodiment of the present invention, an input roller group control component is provided below the printing roller of both the first printing roller group and the second printing roller group, and the input roller group control component is used to drive the printing roller to move up and down along the vertical cutting groove;

[0027] The input roller group control assembly includes linear drive assemblies disposed at both ends of the printing roller, and collar rings disposed on the output shafts of the linear drive assemblies. The linear drive assemblies drive the printing roller away from or close to the surface of the facing paper, and both ends of the printing roller can rotate around the collar rings.

[0028] The present invention has the following beneficial effects when compared with the prior art:

[0029] The present invention determines in real time whether the scale lines printed by the roller printing group are stable, realizes intelligent unmanned replacement of the roller printing group, and automatically replaces the roller printing group put into printing use according to different control methods based on the judgment result, ensuring that the scale lines remain continuous and there will be no intermittent line marks, thus not affecting the later gypsum board cutting work. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained based on the provided drawings.

[0031] Figure 1 It is a structural block diagram of the detection and switching system provided by an embodiment of the present invention;

[0032] Figure 2 It is a finished product drawing of the facing paper printed with scale lines provided by an embodiment of the present invention;

[0033] Figure 3 It is a schematic side sectional structure diagram of the roller printing group provided by an embodiment of the present invention.

[0034] The reference numerals in the drawings are respectively represented as follows:

[0035] 1 - First roller printing group; 2 - Second roller printing group; 3 - Detection module; 4 - Control system; 5 - Input roller group control assembly;

[0036] 121 - Driving roller; 122 - Printing roller; 123 - Side vertical plate; 124 - Transmission belt; 125 - Vertical cutting groove; 126 - Tensioning roller;

[0037] 31 - Light source; 32 - Camera;

[0038] 41 - Image storage module; 42 - Image processing system;

[0039] 51 - Linear drive assembly; 52 - Collar ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0041] As Figure 1 shown, the present invention provides a detection and switching system for the scale lines of gypsum boards. During the production process of paper-faced gypsum boards, a roller printing group is required to print scale lines on the surface of the facing paper to facilitate the cutting of gypsum boards during decoration. In order to ensure continuous roller printing operation, the roller printing group is one for standby and one for use.

[0042] This embodiment realizes intelligent unmanned replacement of the roller printing group, real-time judgment of whether the scale lines printed by the roller printing group are stable, and then automatically replaces the roller printing group put into printing based on the judgment result. Therefore, the roller printing group in use is replaced online automatically without affecting the transmission work of the facing paper, and at the same time, it is ensured that the scale lines are continuous and there will be no intermittent line marks, thus not affecting the later cutting work of gypsum boards.

[0043] The detection and switching system specifically includes:

[0044] At least two roller printing groups are arranged in sequence on the conveying line of the facing paper, and are divided into a first roller printing group 1 and a second roller printing group 2, which are used to switch to another roller printing group for continuous additional printing of scale lines when one of the roller printing groups fails.

[0045] In actual production work, generally two roller printing groups are used, namely the first roller printing group 1 and the second roller printing group 2, so that when the printed scale lines are not clear, it can be timely switched to another roller printing group for use to continuously print clear scale lines online.

[0046] The detection module 3 is arranged downstream of the two roller printing groups and is used to detect the printing image formed by the imprint of the roller printing group in use on the facing paper.

[0047] The control system 4 is electrically connected to the detection module 3 and the roller printing group respectively. The control system 4 selects different control methods to switch the roller printing group put into printing based on the comparison result of the printing image taken by the detection module 3 with the standard image and the roller printing group currently in use, and based on the roller printing group object to be switched for use.

[0048] The second roll printing group 2 is located between the first roll printing group 1 and the detection module 3, and the first roll printing group 1 and the second roll printing group 2 can move along the conveying line of the facing paper, so that the distance between the first roll printing group 1 and the detection module 3 is always an integer multiple of the set scale line specification length, and the distance between the first roll printing group 1 and the second roll printing group 2 is always an integer multiple of the set scale line specification length.

[0049] As a preference of this embodiment, the distance between the first roll printing group 1 and the detection module 3 is most preferably an integer multiple of the set scale line specification length. In this way, when the detection module 3 takes a printed image, the first roll printing group 1 just rotates one week to complete a printing operation. At this time, the length of the printed scale line is the set specification length. Therefore, when the second roll printing group 2 is replaced and put into printing use, the second roll printing group 2 can continue printing after the printed scale line of the first roll printing group 1, ensuring continuous online printing and less waste during later cutting of gypsum boards.

[0050] In addition, as a preference of this embodiment, this embodiment uses image acquisition and processing operations to monitor the scale lines rolled by the roll printing group in real time, so as to judge that the scale line traces become lighter or there are intermittent situations, and then immediately and intelligently adjust the roll printing group in use.

[0051] Specifically, an image storage module 41 is provided in the control system 4, and the image storage module 41 is used to save the scale line standard diagrams of different product specifications.

[0052] The detection module 3 includes a light source 31 arranged below the facing paper and a camera 32 arranged below the facing paper. The camera 32 sends the taken printed image to the control system 4. The control system 4 selects the matching rotation circumferences of the first roll printing group 1 and the second roll printing group 2 according to the set scale line specification length, and the control system 4 uses the image processing system 42 to compare the feature marks on the scale line standard diagram and the printed image. The control system 4 replaces the roll printing group put into printing use according to the comparison result.

[0053] It should be added that in this embodiment, not only scale lines for marking length distances are provided on the first roll printing group 1 and the second roll printing group 2, but also Long brand which can print the company name and trademark is provided. That is, the scale lines in this embodiment are specifically: length markings, company name and trademark, as Figure 2 shown.

[0054] Therefore, when the control system 4 uses the image processing system 42 to compare the feature marks on the scale line standard diagram and the printed image, it is specifically to compare the pixel values of the company name and the Long brand of the trademark on the scale line standard diagram and the printed image. Since the pixel values corresponding to the scale lines are relatively small, while the pixel values of the Long brand of the company name and the trademark are relatively large, comparing the pixel values of the Long brand of the company name and the trademark can improve the accuracy of the comparison result.

[0055] Each time the first roller printing group 1 and the second roller printing group 2 rotate one week, scale line ink marks are formed on the surface of the facing paper. For example, if the set scale line specification length is 60 cm, then each rotation of the first roller printing group 1 and the second roller printing group 2 is 60 cm, and the specific shape of the length mark can refer to the mark on the scale ruler.

[0056] The control system 4 uses the image processing system 42 to compare the pixel value difference between the scale line standard image and the feature marks on the printed image. When the pixel value difference exceeds the set range, the roller printing group used for printing is replaced.

[0057] In this embodiment, in order to improve the accuracy of the pixel value comparison result, the camera 32 in this embodiment mainly shoots the position of the Long brand of the company name and trademark, and according to Figure 2 As shown, this position is the starting position of each group of scale lines. Therefore, the control system 4 determines the time point of the first shooting of the camera 32 according to the transmission speed of the facing paper, the distance between the currently used roller printing group for printing and the camera 32, and combines the time point when the roller printing group starts rolling. The time point of the first shooting of the camera 32 includes feature marks, that is, the Long brand of the company name and trademark.

[0058] And the control system 4 determines the time interval between each shooting of the camera 32 according to the length between two feature marks in the printed image and the transmission speed of the facing paper.

[0059] In this embodiment, in order to reduce the number of images shot by the camera 32, the camera 32 only shoots the position of the Long brand of the company name and trademark each time. Therefore, according to the distance between the positions of the Long brands of the two company names and trademarks and the transmission speed of the facing paper, the time interval between each shooting of the camera 32 can be determined. The camera 32 shoots according to the time interval, and the position of the pixel comparison remains unchanged. At the same time, the number of images is reduced to reduce the memory occupancy and improve the efficiency of image processing.

[0060] Specifically, the implementation method of the image processing system 42 working is specifically as follows:

[0061] The control system 4 uses the image processing system 42 to select the scale line standard image and the feature marks in the printed image, and performs binarization processing on the feature marks;

[0062] Respectively obtain the pixel values of the feature marks on the scale line standard image and the printed image;

[0063] Calculate the pixel value difference between the scale line standard image and the feature marks on the printed image, and compare the pixel value difference with the preset threshold range;

[0064] When the pixel value difference exceeds the preset threshold range, the control system 4 replaces the roller printing group in use for printing. When the pixel value difference is within the preset threshold range, the control system 4 keeps the currently used roller printing group unchanged.

[0065] When the camera 32 captures an image of the current printed scale line and the control system 4 keeps the currently used roller printing group in continuous operation according to the comparison result, the currently used roller printing group continues to perform the rolling printing operation.

[0066] Moreover, when the camera 32 captures an image of the current printed scale line and the control system 4 replaces the roller printing group in use for printing according to the comparison result, it is divided into replacing from the first roller printing group 1 to the second roller printing group 2, or from the second roller printing group 2 to the first roller printing group 1. The control system 4 selects the control method according to the different replaced roller groups.

[0067] The purpose of this embodiment is not only to realize the intelligent replacement of the roller printing group, but also to ensure that the printed scale lines after replacing the roller printing group can be connected continuously without the situation of scale line disconnection. Only in this way can the waste be avoided when cutting the gypsum board.

[0068] Therefore, in this embodiment, when the pixel value difference between the scale line standard image and the characteristic marks on the printed image exceeds the preset threshold range, the control system 4 needs to replace the roller printing group in use for printing.

[0069] When the control system 4 replaces the roller printing group in use for printing from the first roller printing group 1 to the second roller printing group 2 according to the comparison result, that is, the original first roller printing group 1 is used and the first roller printing group 1 is worn, resulting in unclear scale lines, and the second roller printing group 2 needs to be put into use.

[0070] To ensure that a complete scale line mark is formed on the facing paper every time the first roller printing group 1 and the second roller printing group 2 are put into use, both the first roller printing group 1 and the second roller printing group 2 are provided with starting ends. The initial state of the first roller printing group 1 and the second roller printing group 2 when starting the rolling printing operation is that the starting end faces the facing paper. In this way, the fixed position where the first roller printing group 1 is put into use can be ensured, and a complete scale line cycle can be formed on the facing paper.

[0071] At this time, the existing problem is that since there are also printed scale lines on the facing paper between the shooting position of the camera 32 and the first roller printing group 1, in order to avoid the scale line misalignment caused by repeated printing, the control system 4 controls the first roller printing group 1 to stop the rolling printing operation immediately, and the control system 4 determines the time point when the second roller printing group 2 is put into use according to the distance between the first roller printing group 1 and the second roller printing group 2 and the transmission speed of the facing paper. The second roller printing group 2 starts the rolling printing operation according to the calculated time point.

[0072] Of course, in order to prevent the scale lines already existing on the facing paper between the shooting position of the camera 32 and the first roller printing group 1 from being too blurred and affecting the later gypsum board cutting work, the distance between the second roller printing group 2 and the shooting position of the camera 32 can be further set to be an integer multiple of the scale line specification length, and preferably a single multiple. In this way, when the roller printing group for printing is switched from the first roller printing group 1 to the second roller printing group 2, the control system 4 controls the first roller printing group 1 to immediately stop the rolling printing work and controls the second roller printing group 2 to immediately start working.

[0073] In this way, the printed image of the second roller printing group 2 completely coincides with the printed image that has been rolled by the first roller printing group 1, avoiding the situation of misalignment of the scale lines formed by the two printings.

[0074] When the control system 4 switches the roller printing group for printing from the second roller printing group 2 to the first roller printing group 1 according to the comparison result, since there is a certain distance between the second roller printing group 2 and the first roller printing group 1, in order to ensure that continuous and uninterrupted scale lines can also be formed within this distance, the first roller printing group 1 and the second roller printing group 2 start printing work simultaneously, and the second roller printing group 2 stops the rolling printing work after continuously rotating for an integer number of cycles.

[0075] The rotation period of the second roller printing group 2 is the same as the multiple of the scale specification length corresponding to the distance between the second roller printing group 2 and the first roller printing group 1, which can effectively avoid the breakage of the scale lines on the facing paper between the second roller printing group 2 and the first roller printing group 1.

[0076] In this embodiment, an embodiment of the composition structure of the first roller printing group 1 and the second roller printing group 2 is specifically provided.

[0077] As Figure 3 shown, both the first roller printing group 1 and the second roller printing group 2 include a driving roller 121 arranged above the facing paper and a printing roller 122 arranged below the facing paper. The same ends of the driving roller 121 and the printing roller 122 are respectively installed on a side vertical plate 123, and the driving roller 121 and the printing roller 122 are connected by a transmission belt 124.

[0078] The driving roller 121 is connected with a driving motor, and the driving motor drives the driving roller 121 and the printing roller 122 to rotate synchronously and in the same direction. Among them, the first roller printing group 1 and the second roller printing group 2 are independently driven to work.

[0079] As a preference of this embodiment, the driving roller 121 is fixedly installed on the side vertical plate 123, the printing roller 122 is movably installed on the side vertical plate 123, and a vertical cutting groove 125 is provided on the side vertical plate 123, and the printing roller 122 moves up and down along the vertical cutting groove 125.

[0080] Below the printing rollers 122 of the first roller printing group 1 and the second roller printing group 2, there is an input roller group regulating component 5, which is used to drive the printing roller 122 to move up and down along the vertical groove 125.

[0081] The input roller group regulating component 5 includes linear drive components 51 arranged at both ends of the printing roller 122, and collars 52 arranged on the output shafts of the linear drive components 51. The linear drive components 51 drive the printing roller 122 away from or close to the surface of the facing paper, and both ends of the printing roller 122 can rotate around the collar 52.

[0082] The rotation of the driving roller 121 is specifically used to drive the transmission of the facing paper, while the synchronous and same-direction rotation of the printing roller 122 is used to form printed scale lines on the facing paper.

[0083] In order to alternately use the printing rollers 122 of the first roller printing group 1 and the second roller printing group 2, the printing rollers 122 of the first roller printing group 1 and the second roller printing group 2 linearly move along the vertical groove 125 respectively driven by the input roller group regulating component 5.

[0084] The linear drive component 51 can be a linear motor or a pushing cylinder. The linear drive component 51 drives the printing roller 122 to move downwards to disengage this roller printing group from use, and the linear drive component 51 drives the printing roller 122 of the other roller printing group to move up to put this roller printing group into printing use.

[0085] Since the distance between the printing roller 122 and the corresponding driving roller 121 also changes when the printing roller 122 moves, a tension roller 126 is also provided between the driving roller 121 and the printing roller 122. The tension roller 126 is used to always keep the transmission belt 124 in a taut state when the distance between the driving roller 121 and the printing roller 122 changes. Therefore, the driving roller 121 and the printing roller 122 still rotate synchronously and in the same direction through the transmission belt.

[0086] This embodiment determines in real time whether the scale lines printed by the roller printing group are stable, realizes intelligent and unmanned replacement of the roller printing group, and automatically replaces the roller printing group put into printing use according to different regulation methods based on the judgment result, ensuring that the scale lines are continuous and there will be no intermittent line marks, so as not to affect the later gypsum board cutting work.

[0087] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present application, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present application.

Claims

1. A detection and switching system for the scale lines of gypsum boards, characterized in that, Including: At least two roller printing groups, which are sequentially arranged on the conveying line of the facing paper and are divided into a first roller printing group (1) and a second roller printing group (2), and are used to switch to another roller printing group for continuous printing of scale lines when one of the roller printing groups fails; A detection module (3), which is arranged downstream of the two roller printing groups and is used to detect the printed image formed by the imprint of the roller printing group in use on the facing paper; A control system (4), which is electrically connected to the detection module (3) and the roller printing groups respectively. The control system (4) selects different control methods to switch the roller printing group put into printing use based on the comparison result between the printed image captured by the detection module (3) and the standard image, and the roller printing group currently in use, and based on the roller printing group object to be switched to; The second roller printing group (2) is located between the first roller printing group (1) and the detection module (3), and the first roller printing group (1) and the second roller printing group (2) can move along the conveying line of the facing paper, so that the distance between the first roller printing group (1) and the detection module (3) is always an integer multiple of the set scale line specification length, and the distance between the first roller printing group (1) and the second roller printing group (2) is always an integer multiple of the set scale line specification length; An image storage module (41) is provided in the control system (4), and the image storage module (41) is used to save the scale line standard diagrams of different product specifications; The detection module (3) includes a light source (31) arranged below the facing paper and a camera (32) arranged below the facing paper. The camera (32) sends the captured printed image to the control system (4). The control system (4) selects the matching rotation circumferences of the first roller printing group (1) and the second roller printing group (2) according to the set scale line specification length, and the control system (4) uses an image processing system (42) to compare the scale line standard diagram with the feature marks on the printed image, and the control system (4) replaces the roller printing group put into printing use according to the comparison result.

2. The detection and switching system for the scale lines of a gypsum board according to claim 1, wherein The control system (4) determines the time point of the first shot of the camera (32) according to the transmission speed of the facing paper, the distance between the roller printing group currently put into printing use and the camera (32), and in combination with the time point when the roller printing group starts to roll print; And the control system (4) determines the time interval between each shot of the camera (32) according to the length between two feature marks in the printed image and the transmission speed of the facing paper.

3. The detection and switching system for the scale lines of a gypsum board according to claim 1, wherein The control system (4) uses the image processing system (42) to select the scale line standard diagram and the feature marks in the printed image, and performs binarization processing on the feature marks; The pixel values of the feature marks on the scale line standard diagram and the printed image are obtained respectively; Calculate the pixel value difference between the standard diagram of the calibration line and the feature marks on the printed image, and compare the pixel value difference with a preset threshold range; When the pixel value difference exceeds the preset threshold range, the control system (4) replaces the gravure printing group in use for printing. When the pixel value difference is within the preset threshold range, the control system (4) keeps the currently used gravure printing group unchanged.

4. A detection and switching system for the calibration line of a gypsum board according to claim 1, wherein When the camera (32) captures an image of the currently printed calibration line and the control system (4) keeps the currently used gravure printing group working continuously according to the comparison result, the currently used gravure printing group continues to perform the gravure printing work; And when the camera (32) captures an image of the currently printed calibration line and the control system (4) replaces the gravure printing group in use for printing according to the comparison result, it is divided into replacing from the first gravure printing group (1) to the second gravure printing group (2), or replacing from the second gravure printing group (2) to the first gravure printing group (1). The control system (4) selects the control method according to the different replaced roller groups.

5. A detection and switching system for the calibration line of a gypsum board according to claim 4, wherein When the control system (4) replaces the gravure printing group in use for printing from the first gravure printing group (1) to the second gravure printing group (2) according to the comparison result, the control system (4) controls the first gravure printing group (1) to immediately stop the gravure printing work, and the control system (4) determines the time point for the second gravure printing group (2) to be put into use according to the distance between the first gravure printing group (1) and the second gravure printing group (2) and the transmission speed of the facing paper. The second gravure printing group (2) starts the gravure printing work according to the calculated time point; When the control system (4) replaces the gravure printing group in use for printing from the second gravure printing group (2) to the first gravure printing group (1) according to the comparison result, the first gravure printing group (1) and the second gravure printing group (2) are simultaneously put into printing work, and the second gravure printing group (2) stops the gravure printing work after continuously rotating for an integer number of cycles.

6. A detection and switching system for the calibration line of a gypsum board according to claim 4, wherein Both the first gravure printing group (1) and the second gravure printing group (2) are provided with starting ends. The initial state of the first gravure printing group (1) and the second gravure printing group (2) when they start the gravure printing work is that the starting ends face the facing paper.

7. A detection and switching system for the calibration line of a gypsum board according to claim 1, wherein Both the first gravure printing group (1) and the second gravure printing group (2) include a driving roller (121) arranged above the facing paper and a printing roller (122) arranged below the facing paper. The same ends of the driving roller (121) and the printing roller (122) are respectively installed on a side plate (123). The driving roller (121) and the printing roller (122) are connected by a transmission belt (124), wherein; The driving roller (121) is fixedly installed on the side vertical plate (123), the printing roller (122) is movably installed on the side vertical plate (123), and a vertical cutting groove (125) is provided on the side vertical plate (123). The printing roller (122) moves up and down along the vertical cutting groove (125). A tension roller (126) is further provided between the driving roller (121) and the printing roller (122). The tension roller (126) is used to always keep the transmission belt (124) in a taut state when the distance between the driving roller (121) and the printing roller (122) changes.

8. The detection and switching system for the scale line of the gypsum board according to claim 7, characterized in that An input roller group control assembly (5) is provided below the printing rollers (122) of the first roller printing group (1) and the second roller printing group (2). The input roller group control assembly (5) is used to drive the printing rollers (122) to move up and down along the vertical cutting grooves (125); The input roller group control assembly (5) includes a linear driving assembly (51) arranged at both ends of the printing roller (122), and a collar (52) arranged on the output shaft of the linear driving assembly (51). The linear driving assembly (51) drives the printing roller (122) to move away from or close to the surface of the facing paper. Both ends of the printing roller (122) can rotate around the collar (52).

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