An on-line register detection and control device using vision technology

Abstract

This invention belongs to the field of flooring manufacturing and relates to a synchronous online detection and control device for pattern matching using visual technology. Based on an image of the pattern roller surface of an embossing machine acquired by a CCD camera, the device analyzes and processes the image data collected by a computer to automatically determine whether the pattern on the PVC film is misaligned and to determine the necessary adjustments to the film feeding speed, film feeding position, and the speed and position of the sheet feeder. Finally, the detection results are sent to the electrical control box for adjustment. Because it can detect defects that are difficult to detect with the human eye in real time and can perform comprehensive automatic quality monitoring of all products, it completely overcomes the shortcomings of manual visual sampling inspection. Therefore, this system provides an ideal solution for online detection and control of PVC flooring pattern matching.

Description

Technical Field

[0001] This invention belongs to the field of flooring manufacturing and relates to a device for synchronous online detection and control of patterns using visual technology. Background Technology

[0002] Embossing and matching patterns for PVC flooring are highly applied engineering technologies. Roller embossing and matching offer advantages such as high efficiency and good quality. However, in actual production, numerous factors can cause pattern deviations, including wear and tear on transmission mechanism components, positional misalignment, incoordination between the unwinding speed of the coating material and the printing roller, deformation of the coating material pattern on the matching guide roller, and electrical transmission issues. Therefore, the accuracy of continuous embossing and matching is not yet very high, requiring manual intervention when "mismatches" occur. Currently, matching adjustment mainly relies on manual visual inspection. Existing electrical control for matching is an open-loop system; after visually detecting defects, manual adjustments are performed periodically. Since manual adjustment is difficult to perform at such high production speeds, and is easily influenced by subjective factors such as experience and mental state, it has a certain degree of arbitrariness, resulting in large judgment errors and low matching accuracy. Summary of the Invention

[0003] To address the aforementioned problems, this invention discloses a synchronous online detection and control device for pattern matching using visual technology. The technical solution includes: a PVC colored film 1, an unwinding machine 2, an electric XY-axis moving slide 3 for unwinding, a tension detection roller 4, a CCD camera I 5, a CCD camera II 6, a film feeder 7, an electric X-axis moving slide 8 for the film feeder, a rotary encoder 9, a pattern roller 10, an illumination source 11, a dustproof lens 15, a Hall sensor 18, an electrical control box 19, a hanger 20, and a mesh roller 21. The electric XY-axis moving slide 3 for unwinding is mounted on the upper part of the unwinding platform, and the unwinding machine 2 is mounted on it. The PVC colored film 1 is wound onto the unwinding machine 2. The tension detection roller 4 is located on the right side of the printing machine, and the electric X-axis moving slide 8 for the film feeder is located directly below the tension detection roller 4, on which the film feeder 7 is placed. The pattern roller 10 and the mesh roller 21 are located in the middle of the printing machine, both on the same horizontal plane and rotating in opposite directions. The PVC colored film 1 passes through the unwinding machine 2 and the tension roller 21... The detection roller 4 and the sheet feeder 7 are wound onto the grid roller 21; the hanger 20 is installed on the upper part of the unwinding platform, and CCD camera I 5 and CCD camera II 6 are respectively installed on the left and right sides of the lower part of the hanger. An illumination source 11 is installed on the right side of each of the CCD camera I 5 and CCD camera II 6. The dustproof lens 15 is installed on the two CCD cameras respectively. Both CCD cameras are pointing downwards to take pictures. CCD camera I takes pictures of the upper surface of the patterned roller 10, and CCD camera II 6 takes pictures of the upper surface of the grid roller 21; the rotary encoder 9 is installed on the shaft of the patterned roller 10. The rotation of the patterned roller 10 drives the rotary encoder 9 to rotate; the Hall sensor 18 is installed below the rotary encoder 9 and can be used to trigger the CCD camera to take pictures; the electrical control box 19 is located on the left side of the printing machine. The unwinder 2, tension detection roller 4, CCD camera I 5, CCD camera II 6, sheet feeder 7, rotary encoder 9, and Hall sensor 18 are all connected to the electrical control box 19. The electrical control box 19 includes an image acquisition card 12, a microprocessor 13, a control module 14, an image processor 16, and a DA conversion module 17; wherein the image acquisition card 12 is connected to the image processor 16, and the image processor 16 is connected to the microprocessor 13; the microprocessor 13 is connected to the control module 14 and the DA conversion module 17; the DA conversion module 17 is connected to the tension detection roller 4, the rotary encoder 9, and the Hall sensor 18; and the control module 14 is connected to the unwinding machine 2 and the sheet feeder 7.

[0004] The microprocessor 13 is an STM32 or ARM11 controller.

[0005] The image processor 16 operates in either offline or online mode. In offline mode, it saves the images pre-captured by CCD camera I5 and only compares them with the saved images using CCD camera II6. In online mode, it performs real-time detection and compares the images captured by CCD camera I5 and CCD camera II6 in real time. The illumination source 11 is an LED linear array light, which can be in constant illumination mode or periodic illumination mode. In periodic illumination mode, the illumination period is the same as the shooting frequency of CCD camera I5.

[0006] The beneficial effects of this invention are as follows: The vision-based online pattern matching monitoring and control device uses a camera to acquire images of the pattern roller surface of the embossing machine as a reference. It then uses images collected by a computer for analysis and processing to automatically determine whether the pattern on the PVC film is mismatched and to determine the necessary adjustments to the film feeding speed, film feeding position, and the speed and position of the sheet feeder. Finally, the detection results are sent to the electrical control box for adjustment. Because it can detect defects that are difficult for the human eye to spot in real time and can perform comprehensive automatic quality monitoring of all products, it completely overcomes the shortcomings of manual visual sampling inspection. Therefore, this system provides an ideal solution for online pattern matching detection and control of PVC flooring. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the electrical control box structure of the present invention; Figure 3 This is a schematic diagram of the electrical control box connection of the present invention; In the diagram: 101-Unwinding platform, 201-Floor printing machine, 1-PVC colored film, 2-Unwinding machine, 3-Unwinding electric XY axis moving slide, 4-Tension detection roller, 5-CCD camera I, 6-CCD camera II, 7-Film feeder, 8-Film feeder electric X-axis moving slide, 9-Rotary encoder, 10-Patterned roller, 11-Lighting source, 12-Image acquisition card, 13-Central processing unit, 14-Control unit, 15-Dustproof lens, 16-Image processor, 17-Monitoring unit, 18-Hall sensor, 19-Electrical control cabinet, 20-Hanger, 21-Grid roller. Detailed Implementation Example

[0008] like Figure 1 , Figure 2 , Figure 3As shown, the system includes a PVC film 1, an unwinding machine 2, an electric XY-axis moving slide 3 for unwinding, a tension detection roller 4, a CCD camera I 5, a CCD camera II 6, a film feeder 7, an electric X-axis moving slide 8 for film feeder 8, a rotary encoder 9, a patterned roller 10, an illumination source 11, a dustproof lens 15, a Hall sensor 18, an electrical control box 19, a hanger 20, and a mesh roller 21. The electric XY-axis moving slide 3 for unwinding is installed on the upper part of the unwinding platform 101, on which the unwinding machine 2 is mounted, and the PVC film 1 is wound onto the unwinding machine 2. The tension detection roller 4 is located on the right side of the printing machine, and the electric X-axis moving slide 8 for film feeder 7 is located directly below the tension detection roller 4. The patterned roller 10 and the mesh roller 21 are located in the middle of the printing machine, both on the same horizontal plane and rotating in opposite directions. The PVC film 1 is wound onto the mesh roller 21 via the unwinding machine 2, the tension detection roller 4, and the film feeder 7. The hanger 2... The unwinding machine 2, tension detection roller 4, CCD camera I 5, and CCD camera II 6 are respectively installed on the left and right sides of the lower part of the hanger. An illumination source 11 is installed on the right side of each of the CCD camera I 5 and CCD camera II 6. Dustproof lenses 15 are installed on the two CCD cameras respectively. Both CCD cameras are pointing downwards. CCD camera I photographs the upper surface of the patterned roller 10, and CCD camera II 6 photographs the upper surface of the grid roller 21. A rotary encoder 9 is installed on the shaft of the patterned roller 10. The rotation of the patterned roller 10 drives the rotary encoder 9 to rotate. A Hall sensor 18 is installed below the rotary encoder 9 and can be used to trigger the CCD camera to take pictures. The electrical control box 19 is located on the left side of the printing machine. The unwinding machine 2, tension detection roller 4, CCD camera I 5, CCD camera II 6, film feeder 7, rotary encoder 9, and Hall sensor 18 are all connected to the electrical control box 19. The electrical control box 19 includes an image acquisition card 12, a microprocessor 13, a control module 14, an image processor 16, and a DA conversion module 17; wherein the image acquisition card 12 is connected to the image processor 16, and the image processor 16 is connected to the microprocessor 13; the microprocessor 13 is connected to the control module 14 and the DA conversion module 17; the DA conversion module 17 is connected to the tension detection roller 4, the rotary encoder 9, and the Hall sensor 18; and the control module 14 is connected to the unwinding machine 2 and the sheet feeder 7.

[0009] The microprocessor 13 is an STM32 or ARM11 controller.

[0010] The image processor 16 operates in either offline or online mode. In offline mode, it saves the images pre-captured by CCD camera I5 and only compares the images with those captured by CCD camera II6. In online mode, it performs real-time detection and compares the images captured by CCD camera I5 and CCD camera II6 in real time.

[0011] The lighting source 11 is an LED linear array light, which can be in constant light mode or periodic lighting mode. The lighting cycle of the periodic lighting mode is the same as the shooting frequency of the CCD camera I5.

[0012] The working principle of this invention is as follows: The rotary encoder 9 is installed on the shaft of the patterned roller 10. When the patterned roller 10 starts to rotate, the microprocessor 13 starts the rotary encoder 9, sends the pulse signal output by the rotary encoder 9 into the microprocessor 13 and converts it into a speed signal to control the speed of the film feeder 7 so that it is synchronized with the speed of the patterned roller 10. The Hall sensor 18 triggers the shooting of one or two CCD cameras according to the settings. When the film feeder 7 pulls the PVC film 1 through the tension detection roller 4, the tension sensor outputs a millivolt signal. The millivolt signal is amplified by the power amplifier and then input into the microprocessor 13 to convert it into a speed control for unwinding speed, so as to achieve constant tension unwinding. The light source 11 is aligned with the PVC color film 1. The shooting frequency of CCD camera I5 is set the same as that of CCD camera II6, and continuous shooting is performed to capture the pattern on the pattern roller 10 and the pattern on the PVC color film 1 on the grid roller 21. When the PVC floor printing machine 201 starts matching patterns, the camera acquires images. The images captured by the two cameras are processed by the image processing unit 17 to obtain the online detection results and make calculations. Finally, the processed offset data is transmitted to the control module to make corresponding adjustments to the unwinding machine 2 and the unwinding machine 7.

[0013] Before activating offline mode, the embossing machine operates normally and the pattern matching effect is ideal. CCD camera I5 can pre-capture and save images of the pattern roller 10 of the embossing machine at a set frequency. Based on the order of the captured images, corresponding features are set and templates are saved sequentially. For example, if a pattern is captured in the first image, a frame is drawn at a distinctive location in that image as a feature template. Templates are set sequentially for each corresponding shape pattern, and the corresponding template center position's horizontal coordinates X1, X2, X3…X10 and vertical coordinates Y1, Y2, Y3…Y10 are saved. In offline mode, CCD camera I5 stops capturing images and only compares the image captured by CCD camera II6 with the saved template. The image captured by CCD camera II6 is compared with the horizontal and vertical coordinates of the template center position saved during offline template setting, and the horizontal coordinates x1, x2, x3…x10 and vertical coordinates y1, y2, y3…y10 of the current image center position are recorded. At this time, the relative distances between the vertical coordinates of each template are compared with the relative distances between the vertical coordinates of each template during offline setting, and the matching deviation results d1, d2, d3…d9 and l1, l2, l3…l9 of the ball can be obtained, thereby controlling the speed of unwinding machine 2 and unwinding machine 7.

[0014] When online mode is activated, CCD camera I5 captures several images for each revolution of the pattern roller 10. Because of the triggering effect of Hall sensor 18, the starting position and interval of each image are identical, eliminating the need for template positioning of the search area. CCD camera II6 is set to the same shooting frequency as CCD camera I5 to capture images of the PVC film 1. By comparing the features of the images captured by the two cameras, the pattern matching deviation can be calculated, allowing for corresponding adjustments to the unwinding machine 2 and the sheet unwinding machine 7.

[0015] The power supply for the electrical control box 19 is provided by the main power supply of the floor printing machine 201.

[0016] Using STM32 or ARM11 to acquire images or data and control motors is a widely used existing technology. Those skilled in the art can easily learn about the interface type and function of the microcontroller by consulting the technical manual, and determine the specific connection method of the circuit through a limited number of experiments based on actual needs.

[0017] While the specific embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and modifications or variations without creative effort are still within the protection scope of the present invention.

Claims

1. An on-line registration detection and control device using vision technology, characterized in that: The components include PVC film (1), unwinder (2), unwinder electric XY axis moving slide (3), tension detection roller (4), CCD camera I (5), CCD camera II (6), film feeder (7), film feeder electric X-axis moving slide (8), rotary encoder (9), patterned roller (10), lighting source (11), dustproof lens (15), Hall sensor (18), electrical control box (19), hanger (20), and mesh roller (21); among which the unwinder electric XY axis moving slide (3) is equipped with a PVC film (1), an unwinder (2), an unwinder electric XY axis moving slide (3), a tension detection roller (4), a CCD camera I (5), a CCD camera II (6), a film feeder (7), a film feeder electric X-axis moving slide (8), a rotary encoder (9), a patterned roller (10), an illumination source (11), a dustproof lens (15), a Hall sensor (18), an electrical control box (19), a hanger (20), and a mesh roller (21). Above the printing press, an unwinding machine (2) is installed, and the PVC film (1) is wound on the unwinding machine (2); the tension detection roller (4) is located on the right side of the printing press, and the electric X-axis moving slide (8) of the sheet feeder is located directly below the tension detection roller (4), on which the sheet feeder (7) is placed; the pattern roller (10) and the grid roller (21) are located in the middle of the printing press, and the two are located on the same horizontal plane and rotate towards each other; the PVC film (1) is wound onto the grid roller (21) through the unwinding machine (2), the tension detection roller (4) and the sheet feeder (7). The hanger (20) is installed on the upper part of the unwinding platform. CCD camera I (5) and CCD camera II (6) are installed on the left and right sides of the lower part of the hanger, respectively. A light source (11) is installed on the right side of each of the CCD camera I (5) and CCD camera II (6). The dustproof lens (15) is installed on the two CCD cameras respectively. Both CCD cameras are shooting downwards. CCD camera I shoots the upper surface of the patterned roller (10), and CCD camera II (6) shoots the upper surface of the grid roller (21). The rotary encoder (9) is installed on the shaft of the patterned roller (10). The rotation of the patterned roller (10) drives the rotary encoder (9) to rotate. The Hall sensor (18) is installed below the rotary encoder (9) and can be used to trigger the CCD camera to take pictures. The electrical control box (19) is located on the left side of the printing machine. The unwinding machine (2), tension detection roller (4), CCD camera I (5), CCD camera II (6), film feeder (7), rotary encoder (9), and Hall sensor (18) are all connected to the electrical control box (19). The electrical control box (19) includes an image acquisition card (12), a microprocessor (13), a control module (14), an image processor (16), and a DA conversion module (17); wherein the image acquisition card (12) is connected to the image processor (16), and the image processor (16) is connected to the microprocessor (13); the microprocessor (13) is connected to the control module (14) and the DA conversion module (17); the DA conversion module (17) is connected to the tension detection roller (4), the rotary encoder (9), and the Hall sensor (18); the control module (14) is connected to the unwinding machine (2) and the sheet feeder (7); The lighting source (11) is an LED linear array light, which can be in constant lighting mode or periodic lighting mode. The lighting period of the periodic lighting mode is the same as the shooting frequency of the CCD camera I (5).

2. The online detection and control device for synchronization of register using vision technology according to claim 1, characterized in that: The microprocessor (13) is an STM32 or ARM11 controller.

3. The apparatus for online detection and control of synchronization of register using vision technology as claimed in claim 1 wherein: The image processor (16) operates in either offline or online mode. In offline mode, the images pre-captured by CCD camera I (5) are saved, and only CCD camera II (6) is activated to compare with the saved images. In online mode, real-time detection is performed, and the images captured by CCD camera I (5) and CCD camera II (6) are compared in real time.

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