A punching sheet stacking detection system and method based on visual monitoring

Abstract

The present application discloses a punching sheet stacking detection system and method based on visual monitoring, which relates to the field of image processing technology. The system includes a mechanical transmission module, an image acquisition module, a transmission control module, an image segmentation module and an image analysis module. The transmission control module controls the transfer platform to stop transmission and controls the image acquisition module to start image acquisition according to the pressure data of the detection position and the transmission time, and controls the transfer platform to resume transmission according to the image acquisition duration; the image segmentation module fuses the surface images of each punching sheet and the surface area images with the same secondary number according to the image cutting rules; and compares each fused area image with the corresponding standard secondary image to determine the similarity of each fused area image to determine whether the punching sheet corresponding to the folder is qualified. The present application obtains surface images of the punching sheet from multiple light source angles, comprehensively captures the surface information of the stacking sheet and avoids missing possible defect details.

Description

Technical Field

[0001] The present application relates to the field of image processing technology, and in particular to a punching sheet overlap detection system and method based on visual monitoring. Background Art

[0002] In modern industrial production, punching sheets are widely used in many electrical equipment fields such as motors and transformers. The performance and reliability of these equipment depend to a large extent on the quality of the punching sheets. With the development of science and technology, industrial equipment is moving towards high performance and high precision, which puts more stringent requirements on the quality of the punching sheets. Minor defects such as chipping, deformation, oil stains or rust may lead to reduced equipment performance, shortened lifespan or even failure. Therefore, a high-precision detection system is needed to ensure the quality of the punching sheets.

[0003] The prior art provides a visual inspection device for stamped terminals, comprising a transmission module, a shooting module, and an image processing module; the transmission module is used to transmit the stamped terminals to be quality inspected to the bottom of the shooting module; the shooting module is used to shoot the stamped terminals to obtain an appearance image of the stamped terminals; the image processing module is used to perform brightness adjustment processing on the appearance image, and then perform image recognition processing to determine whether the stamped terminals meet the preset quality requirements; the brightness adjustment processing of the appearance image includes: classifying the pixels in the appearance image to divide the pixels into one type of pixels and two types of pixels; using a preset first processing function to perform brightness adjustment processing on the first type of pixels, and using a preset second processing function to perform brightness adjustment processing on the second type of pixels to obtain a brightness adjusted image. The above scheme effectively improves the accuracy of the brightness processing results, thereby improving the accuracy of the quality inspection results. It can be seen that the invention does not take into account the problem of low detection accuracy caused by the inability to fully capture the surface information of the laminated sheets due to the single light source shooting the image. Summary of the Invention

[0004] The purpose of this application is to provide a system and method for detecting the stacking of punched sheets based on visual monitoring, so as to solve the problem in the prior art of low detection accuracy caused by the inability to fully capture the surface information of the stacked sheets due to the single light source shooting the image.

[0005] On the one hand, the embodiment of the present application proposes a punching sheet stacking detection system based on visual monitoring, comprising:

[0006] A mechanical transmission module includes a transfer platform and a mechanical arm, wherein the mechanical arm is used to carry the punched sheet to the transfer starting end of the transfer platform, and the transfer platform is used to transfer the punched sheet from the transfer starting end to the detection position;

[0007] The image acquisition module includes a fill light unit for providing a plurality of shooting light sources at different angles, an image acquisition unit for acquiring images of the film surface, and a shooting control unit for controlling the fill light unit to sequentially activate the shooting light sources at each angle, controlling the image acquisition unit to acquire images, and packaging a plurality of film surface images of a single film into a folder and generating a primary number for each film surface image according to the image acquisition sequence;

[0008] a transmission control module, connected to the mechanical transmission module and the image acquisition module, respectively, for controlling the transfer platform to stop transmission and control the image acquisition module to start image acquisition based on the pressure data of the detection position and the transmission time, and controlling the transfer platform to resume transmission based on the image acquisition time;

[0009] An image segmentation module, connected to the image acquisition module, is used to divide each punched sheet surface image into a plurality of surface region images according to an image segmentation rule and generate corresponding secondary numbers, and fuse the surface region images with the same secondary number in the folder to form a corresponding fused region image;

[0010] an image analysis module connected to the image segmentation module, for comparing each of the fused region images in a single folder with the corresponding standard secondary image to determine the similarity of each fused region image, and determining whether the corresponding film of the folder is qualified based on the similarity of each fused region image;

[0011] In which, in a single image acquisition, the number of surface images of the punched film generated is equal to the number of shooting light sources turned on, the surface area image includes a center area image and an edge area image, and the standard secondary image is a surface area image of the punched film standard part at the same position.

[0012] According to the punching sheet overlap detection system based on visual monitoring according to an embodiment of the present application, the detection position is located on the base of the transfer platform, and a pressure sensor for determining the pressure data of the transfer platform on the detection position is provided between the detection position and the transfer platform.

[0013] According to the punching sheet stacking detection system based on visual monitoring in an embodiment of the present application, the transmission control module determines whether the punching sheet has reached the detection position based on the pressure data and transmission time at the detection position, wherein:

[0014] If the pressure data is within the reference pressure range and the transmission time is within the preset time range, it is determined that the punching sheet has arrived at the detection position;

[0015] If the pressure data is not within the reference pressure range and / or the transmission time is not within the preset time range, it is determined that the punching sheet has not reached the detection position.

[0016] According to the punching sheet stacking detection system based on visual monitoring in an embodiment of the present application, the conveying control module controls the transfer table to stop conveying and controls the image acquisition module to start image acquisition based on the result of determining that the punching sheet has arrived at the detection position;

[0017] Wherein, controlling the image acquisition module to start image acquisition includes:

[0018] The shooting control unit controls the fill light unit to sequentially turn on the shooting light sources at various angles and controls the image acquisition unit to perform image acquisition when the shooting light sources at various angles are turned on.

[0019] According to the punching sheet overlap detection system based on visual monitoring in an embodiment of the present application, the conveying control module determines the end of image acquisition of a single punching sheet according to the image acquisition time of the punching sheet and controls the transfer table to resume conveyance, wherein,

[0020] If the image acquisition time of a single punched sheet is equal to the preset time, it is determined that the image acquisition of the punched sheet is completed and the transfer table is controlled to resume transmission.

[0021] According to the punching sheet overlap detection system based on visual monitoring in an embodiment of the present application, the image segmentation module pre-stores an image segmentation rule, the image segmentation rule including determining, based on a reference area ratio, to divide each punching sheet surface image into an edge image and a center image, and determining, based on a detection accuracy, a first reference number and a second reference number to respectively segment the edge image and the center image into a first reference number of edge region images and a second reference number of center region images;

[0022] The central image and the corresponding punched film surface image are similar images, and the geometric center of the central image is the geometric center of the corresponding punched film surface image.

[0023] According to the punching sheet overlap detection system based on visual monitoring in an embodiment of the present application, the reference area ratio is the area ratio of the center image to the punching sheet surface image.

[0024] According to the punching and stacking detection system based on visual monitoring in an embodiment of the present application, a machine learning model is preset in the image analysis module to determine the similarity of the images of each of the fusion areas.

[0025] According to the punching and lamination detection system based on visual monitoring in the embodiment of the present application, the image analysis module determines whether the punching corresponding to the folder is qualified according to the similarity of the images of each fusion area, including:

[0026] Whether the corresponding punched film has a missing corner is determined based on the similarity between the fused area images corresponding to each edge area image, and whether the corresponding punched film has a defect is determined based on the similarity between the fused area images corresponding to each center area image.

[0027] On the other hand, the embodiment of the present application further proposes a punching sheet overlap detection method based on visual monitoring, comprising:

[0028] Step S1, obtaining pressure data and transmission time data of the detection position in real time;

[0029] Step S2, determining whether the punching sheet has reached the detection position based on the pressure data and the transmission time at the detection position;

[0030] Step S3, controlling the transfer platform to stop conveying and controlling the image acquisition module to start image acquisition based on the result of the judgment of reaching the detection position, and controlling the robotic arm to transport the punched sheet to the conveying starting end of the transfer platform;

[0031] Step S4, controlling the transfer table to resume conveyance according to the image acquisition time of the developed film.

[0032] In summary, the beneficial technical effects of the present application are as follows: the punching sheet stacking detection system based on visual monitoring provided by the present application brings an efficient and accurate solution to punching sheet detection through the coordinated work of the mechanical transmission module, the image acquisition module, the transmission control module, the image segmentation module and the image analysis module; wherein, the transfer table and the robotic arm of the mechanical transmission module cooperate to ensure that the punching sheet can accurately reach the detection position, the image acquisition module utilizes a multi-angle fill light unit and a high-resolution camera to comprehensively obtain the punching sheet surface image under different light source angles of the stacked sheets and reasonably number each punching sheet surface image; the transmission control module accurately detects the punching sheet based on the pressure at the detection position and the transmission time The coordination of the transfer table control and image acquisition ensures the integrity and accuracy of image acquisition. The image segmentation module divides the surface image into different regions based on pre-stored image cutting rules and fuses the surface region images at different locations using a suitable fusion method to highlight the oil and rust characteristics of the center region image and the chipped corners and deformation characteristics of the edge region image. The image analysis module compares each fused region image with the corresponding standard secondary image to determine the quality of the punched film based on the similarity of the comparison results. The entire system effectively ensures the accuracy of detection and improves detection efficiency during batch production inspection based on the standard secondary image determined in the early stage of standard parts.

[0033] The transmission control module combines the pressure data and transmission time at the detection position to accurately determine whether the punched sheet has reached the detection position. The pressure data is based on a reference pressure range determined by the quality of the standard parts for the punched sheet, and the transmission time is based on a preset time range determined by the spacing between adjacent punched sheets and the transmission speed. This dual-factor judgment mechanism ensures the accuracy of the judgment. In addition, in actual operation, the appropriate transmission speed set considering the high-precision detection requirements of the punched sheets, as well as the setting of the time error as small as possible, both help to more accurately control the stopping time of the transfer table and ensure that the punched sheet is accurately within the shooting range of the image acquisition unit. Once it is determined that the punched sheet has reached the detection position, the transmission control module can effectively control the transfer table to stop transmission and accurately instruct the shooting control unit to turn on the light sources of the fill light unit at various angles. At the same time, the image acquisition unit performs image capture when each light source is turned on, so that the entire image capture process is closely coordinated with the transmission of the punched sheet in an orderly manner, greatly improving the efficiency of the detection system and the reliability of the detection results.

[0034] The image segmentation module's pre-stored image segmentation rules divide the stamping surface image into an edge image and a center image based on a reference area ratio. The module also determines a first reference number and a second reference number based on detection accuracy, thereby segmenting the edge image and center image into a corresponding number of regional images. This design can rationally determine the number of pixels comprising the surface regional image based on detection accuracy (high, medium, or low), avoiding unnecessary computation and resource waste. Furthermore, by rationally setting the reference area ratio, it ensures accuracy when using the stamping center to detect oil stains and rust, and when using the stamping edge to detect chipping or deformation. This makes image segmentation more targeted and scientific, effectively improving the efficiency and quality of subsequent image analysis and laying a solid foundation for the entire inspection system to accurately determine whether the stamping is qualified.

[0035] The machine learning model preset within the image analysis module can accurately determine the similarity of the images in each fused area, and judge whether the punched film has missing corners or defects by measuring the similarity between the fused area images corresponding to the edge area images and the center area images and their corresponding standard secondary images. The preset similarity is set according to different detection accuracies, enabling the image analysis module to efficiently and accurately evaluate the quality of punched films and effectively screen out defective products, providing reliable guarantees for ensuring the quality of punched films and greatly improving the product qualification rate and quality stability throughout the entire production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a connection diagram of a punching sheet stacking detection system based on visual monitoring according to an embodiment of the present application;

[0037] Figure 2 This is a schematic diagram of the composition of a single folder in an embodiment of the present application;

[0038] Figure 3This is a step diagram of a punching sheet overlap detection method based on visual monitoring according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0040] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0041] The term "plurality" used in this application refers to two or more (including two).

[0042] On the one hand, the following Figures 1 to 2 The punching sheet overlap detection system based on visual monitoring in an embodiment of the present application is described in detail.

[0043] See attached Figure 1 and attached Figure 2 , which are respectively a connection diagram of the punching sheet overlay detection system based on visual monitoring in an embodiment of the present application and a schematic diagram of the composition of a single folder in an embodiment of the present application.

[0044] The present application provides a punching sheet stacking detection system based on visual monitoring, comprising:

[0045] The mechanical transmission module includes a transfer platform and a robotic arm. The robotic arm is used to transport the punched sheet to the transfer starting end of the transfer platform, and the transfer platform is used to transport the punched sheet from the transfer starting end to the inspection position. It can be understood that the robotic arm transports the punched sheet to the starting end of the transfer platform and stably transports it to the inspection position through the transfer platform, ensuring the orderly transportation of the punched sheet during the inspection process, improving the efficiency of the overall inspection process, and avoiding problems such as position deviation that may be caused by manual handling.

[0046] The image acquisition module includes a fill light unit for providing a plurality of shooting light sources at different angles, an image acquisition unit for acquiring images of the film surface, and a shooting control unit for controlling the fill light unit to sequentially activate the shooting light sources at each angle and controlling the image acquisition unit to perform at least one image acquisition (usually one acquisition per position), package a plurality of film surface images of a single film into a folder, and generate a primary number for each film surface image according to the image acquisition sequence;

[0047] It is understood that the fill light unit can be a fill light device capable of providing multi-angle light sources in the prior art, and the image acquisition unit can be a camera with a shooting function in the prior art (in practice, a high-resolution HD camera is preferably used); in addition, the image acquisition unit is usually fixed at the center of the fill light unit, and the plane formed by the camera lens and the light sources of the image acquisition unit should be parallel to the transfer platform, and the straight line formed by the image acquisition unit and the detection position should be perpendicular to the transfer platform;

[0048] In implementation, the fill light unit is fixedly connected to both sides of the base of the transfer platform through two fixed support rods, and the plane formed by the two fixed support rods is perpendicular to the base plane;

[0049] Attachment Figure 2 It shows that there are n light sources at different angles and a single film surface image is cut into m surface area images according to the image cutting rules, and also includes m fusion area images, which are respectively recorded as m1...mm. It can be understood that for any numbered film (any film will have its own unique identification code when it is prepared, and the number here is the corresponding identification code), the film surface images of n light sources at different angles are collected and numbered according to the order of collection (that is, if the fill light unit has n light sources at different angles, n film surface images will be collected and numbered as 1, 2, 3,..., n), and the film surface images of these n light sources at different angles are enclosed in a folder (the name of this folder is the number of the film); therefore, in one embodiment, the fill light unit has 3 light sources at different angles, and a film is numbered AA, then the folder named AA should contain film surface images named 1, 2, and 3 respectively;

[0050] It is understandable that in practice, the surface image acquisition process at a single light source angle may overlook some surface defects, that is, the application of light will affect the analysis of the image surface. Therefore, the fill light unit provides multiple shooting light sources at different angles to cooperate with the image acquisition unit, which can obtain surface images of the punched film at multiple light source angles, comprehensively capture the surface information of the stacked film to avoid missing possible defect details; the shooting control unit numbers the acquired images in sequence and packages them into folders, and each punched film has its own unique identifier, which facilitates subsequent image processing and analysis and avoids confusion of image data; the image acquisition unit is fixed to the center of the fill light unit, and the plane formed by the camera lens and the light sources is parallel to the transfer platform, and the straight line formed by the detection position is perpendicular to the transfer platform. At the same time, the fill light unit is connected to the transfer platform in a specific way, which ensures the stability and consistency of the acquired image and reduces image errors caused by unstable equipment position;

[0051] a transmission control module, connected to the mechanical transmission module and the image acquisition module, respectively, for controlling the transfer platform to stop transmission and control the image acquisition module to start image acquisition based on the pressure data of the detection position and the transmission time, and controlling the transfer platform to resume transmission based on the image acquisition time;

[0052] It can be understood that the transmission control module can accurately control the transfer table to stop and start image acquisition based on the pressure data and transmission time at the detection position, and can also control the transfer table to resume transmission based on the image acquisition time, thus achieving precise coordination between mechanical transmission and image acquisition, ensuring that each punched sheet can be accurately imaged at the appropriate position and time, thereby improving the accuracy and efficiency of detection;

[0053] an image segmentation module connected to the image acquisition module, configured to receive the punched film folders sent by the shooting control unit, divide the punched film surface images in the folders into a plurality of surface region images according to image segmentation rules and generate corresponding secondary numbers, and fuse the surface region images with the same secondary number in the folders to form corresponding fused region images;

[0054] It can be understood that any punched film surface image determined according to the image segmentation rule is divided into the same number of surface region images, and each surface region image with the same secondary number should be at the same position on the punched film surface image;

[0055] It is understood that the name of each surface area image is a combination of a primary number and a secondary number, and the combination can be any way, as long as the primary number portion and the secondary number portion can be distinguished. In one embodiment, the primary number and the secondary number of a surface area image are 1 and 02 respectively, and the name of the surface area image can be 102, 1.02, 1-02, 10002, etc.

[0056] In the above implementation, there are three film surface images named 1, 2, and 3 in the folder named AA, and the image cutting rule has determined how to divide the film surface image into m regional surface images and determine that the regional surface images at each position are numbered one of 1 to m; the film surface image named 1 can be divided into m regional surface images and named 1-1, 1-2, 1-3, ..., 1-m respectively, and the film surface image named 2 can be divided into m regional surface images and named 2-1, 2-2, 2-3, ..., 2-m respectively, and the film surface image named 3 can be divided into m regional surface images and divided into m regional surface images. They are named 3-1, 3-2, 3-3, ..., 3-m; at this time, there should be 3 film surface images and 3m regional surface images in the folder named AA, and these 3m regional surface images are 1-1, 1-2, 1-3, ..., 1-m, 2-1, 2-2, 2-3, ..., 2-m, 3-1, 3-2, 3-3, ..., 3-m; then for the three regional surface images 1-1, 2-1 and 3-1 with the secondary number 1, they are in the same position in their corresponding film surface images. If 1-1 is in the upper right corner of the film surface image named 1, then 2-1 and 3-1 are also in the upper right corner of the film surface images named 2 and 3 respectively;

[0057] In implementation, when performing image fusion on each surface region image with the same secondary number in a folder to form a corresponding fused region image, different fusion methods are determined according to the surface region images, including:

[0058] (1) The principal component analysis (PCA) fusion method is used to fuse the central area images with the same secondary number to form a fused area image with the secondary number. It can be understood that PCA can help screen out the most important information for fusion, while reducing data redundancy and highlighting the main features. When detecting oil stains and rust on laminated sheets, the main characteristic areas of these defects can be highlighted.

[0059] (2) Using a fusion method based on multi-resolution analysis (such as wavelet transform) to fuse the edge region images with the same secondary number to form a fused region image with the secondary number; it can be understood that wavelet transform can extract the most useful edge information from photos at different angles and fuse them together to obtain a clearer and more accurate edge image. When detecting whether the edges of stacked films are missing or deformed, wavelet transform fusion can better highlight the edge details;

[0060] It can be understood that after the punched sheet surface image is divided into several surface area images according to the image segmentation rules, the principal component analysis (PCA) fusion method is used for the central area image to highlight the main characteristic areas of defects such as oil stains and rust; the fusion method based on multi-resolution analysis (such as wavelet transform) is used for the edge area image to better highlight edge details such as missing corners or deformation. This targeted processing helps to more accurately detect different types of defects;

[0061] an image analysis module connected to the image segmentation module, for comparing each of the fused region images in a single folder with the corresponding standard secondary image to determine the similarity of each fused region image, and determining whether the corresponding film of the folder is qualified based on the similarity of each fused region image;

[0062] It is understandable that the standard secondary image corresponding to the fused region image has the same secondary number as the fused region image;

[0063] It can be understood that the comparison method of comparing the fused region image with the corresponding standard secondary image to determine the similarity and then judge whether the punched film is qualified can effectively ensure product quality in batch production testing, ensure that unqualified punched films are accurately screened out, and improve the quality control level of the entire production process. In addition, preparing punched film standard parts and determining the standard secondary image before batch production testing provides a reliable basis for subsequent comparative analysis, making the test results more authoritative and accurate.

[0064] In which, in a single image acquisition, the number of surface images of the punched film generated is equal to the number of shooting light sources turned on, the surface area image includes a center area image and an edge area image, and the standard secondary image is a surface area image of the punched film standard part at the same position.

[0065] It is understandable that before mass production testing, several punched sheet standard parts are prepared in an experiment, and a standard secondary image is determined based on each punched sheet standard part.

[0066] Specifically, the detection position is located on the base of the transfer platform, and a pressure sensor for determining pressure data of the transfer platform on the detection position is provided between the detection position and the transfer platform.

[0067] In implementation, the pressure sensor can be any high-precision pressure sensor in the existing technology; it can be understood that high-precision pressure measurement can avoid the transfer table stopping too early or too late due to pressure data errors, thereby ensuring that each punched sheet can be imaged at the optimal position, improving the accuracy and reliability of the detection, and ensuring the smooth progress of the entire detection process.

[0068] Specifically, the transmission control module determines whether the punching sheet reaches the detection position according to the pressure data and transmission time of the detection position, wherein:

[0069] If the pressure data is within the reference pressure range and the transmission time is within the preset time range, it is determined that the punching sheet has arrived at the detection position;

[0070] If the pressure data is not within the reference pressure range and / or the transmission time is not within the preset time range, it is determined that the punching sheet has not reached the detection position.

[0071] It can be understood that the reference pressure range is determined according to the mass of the punching standard parts. The average mass m and mass standard deviation m1 of several punching standard parts prepared in the experiment are determined. The reference pressure range is (m-m1)×g to (m+m1)×g (g is the acceleration due to gravity, which is about 9.8N / kg). In practice, the unit of mass is kg and the unit of reference pressure is N.

[0072] It can be understood that when a punch is delivered to the detection position, a new punch is placed at the start of the delivery, and when the next punch is delivered to the detection position, a new punch is placed at the start of the delivery. When the transfer speed of the transfer table remains unchanged, the distance between any two adjacent punches should be equal.

[0073] It is understandable that the preset time range is determined based on the spacing between two adjacent punches on the transfer table and the conveying speed, and the standard preset time = the spacing between two adjacent punches on the transfer table ÷ the conveying speed; in practice, the precision requirements for punching are relatively high, so the conveying speed is not very fast, generally 1m / min to 5m / min, and is often set to 2m / min. This speed range not only meets the basic requirements of production efficiency, but also ensures the stability of the punches during the conveying process, avoids image acquisition blur or other problems caused by excessive speed, and lays the foundation for subsequent accurate detection; in practice, the preset time range ∈ [standard preset time - time error, standard preset time + time error], generally the time error is ≤1s, in order to ensure that the punch is within the shooting range of the image acquisition unit when the transfer table stops, the time error should be as small as possible, preferably set to 0.5s, introducing the time error in the setting of the preset time range and trying to control it to a smaller value (generally ≤1s, preferably 0.5s), can more accurately control the stop time of the transfer table, ensure that the punch is within the shooting range of the image acquisition unit when the transfer table stops, and further improve the quality of image acquisition and the reliability of the detection results;

[0074] It is understandable that the transmission control module uses pressure data and transmission time as two factors to determine whether the punch has reached the detection position, and comprehensively considers the weight of the punch and the time factors in the transmission process. This method is more accurate than single-factor judgment and reduces the possibility of misjudgment; the reference pressure range is determined according to the quality of the punch standard parts, and the range is set by calculating the average quality and quality standard deviation of the standard parts, so that the pressure judgment is closely related to the physical properties of the actual punch, ensuring that punches of different batches but that meet the standards can be accurately identified, and effectively avoiding position judgment errors caused by individual quality differences of the punches; the preset time range is determined according to the spacing between adjacent punches on the transfer table and the transmission speed. This method fully considers the dynamic factors in the transmission process. In actual production, since the spacing between punches and the transmission speed are relatively stable, the position of the punch can be accurately judged by reasonably setting the preset time range to ensure the timeliness and accuracy of the detection.

[0075] Specifically, the conveying control module controls the transfer platform to stop conveying and controls the image acquisition module to start image acquisition according to the result of determining whether the punched sheet has arrived at the detection position;

[0076] Wherein, controlling the image acquisition module to start image acquisition includes:

[0077] The shooting control unit controls the fill light unit to sequentially turn on the shooting light sources at various angles and controls the image acquisition unit to perform at least one image acquisition when turning on the shooting light sources at various angles.

[0078] It is understandable that when it is determined that the film has arrived at the detection position, the transmission control module promptly controls the transfer table to stop transmission and simultaneously starts the image acquisition module to start image acquisition. This rapid coordination capability ensures seamless connection between image acquisition and film transmission, avoiding problems such as omission or incomplete image acquisition due to time delays or asynchronous operations; during the image acquisition process, the shooting control unit, under the command of the transmission control module, orderly controls the fill light unit to turn on the shooting light sources at various angles in turn, and allows the image acquisition unit to perform at least one image acquisition when each light source is turned on. This standardized operating procedure ensures comprehensive acquisition of the image information of the film from different angles, providing a rich and accurate data source for subsequent image analysis.

[0079] Specifically, the conveying control module determines the end of image acquisition of a single punched sheet according to the image acquisition time of the single punched sheet and controls the transfer table to resume conveyance, wherein:

[0080] If the image acquisition time of a single punched sheet is equal to the preset time, it is determined that the image acquisition of the punched sheet is completed and the transfer table is controlled to resume transmission.

[0081] It is understandable that the fill light unit can have 3 to 10 light sources at different angles. Setting too many light source angles will lead to data redundancy and greatly increase the waste of analysis and processing time and resources. Therefore, usually setting 4 light sources at different angles can achieve accurate analysis of defects on the surface of the punched film; in advance experiments, the average time for turning on and shooting light sources at each angle is determined, and the product of the number of light sources at different angles and the average time is determined as the preset duration. In one implementation, the preset duration is 4 times the average time.

[0082] It can be understood that the transmission control module determines whether the acquisition is completed based on the image acquisition time of a single film and controls the transfer platform to resume transmission, and performs corresponding operations when the image acquisition time is equal to the preset time. This control method reasonably sets the number of light source angles of the fill light unit, and determines the average time of turning on and shooting the light sources of each angle in the experiment in advance to calculate the preset time, thereby accurately coordinating the image acquisition and transfer platform transmission processes, ensuring efficient and stable operation of the detection system, ensuring the integrity of the film image acquisition, and avoiding unnecessary waste of time, effectively improving the efficiency and reliability of the entire detection process.

[0083] Specifically, the image segmentation module pre-stores an image segmentation rule, the image segmentation rule including determining, based on a reference area ratio, to divide each punched sheet surface image into an edge image and a center image, and determining, based on a detection accuracy, a first reference number and a second reference number to respectively segment the edge image and the center image into a first reference number of edge region images and a second reference number of center region images;

[0084] The central image and the corresponding punched film surface image are similar images, and the geometric center of the central image is the geometric center of the corresponding punched film surface image.

[0085] It is understandable that the area of the center image is much larger than the area of the edge area, so the first reference number is much smaller than the second reference number; in implementation, each surface area image detected with high precision is composed of 1 to 4 adjacent pixels, each surface area image detected with medium precision is composed of 1 to 10 adjacent pixels, and each surface area image detected with low precision is composed of 1 to 20 adjacent pixels;

[0086] In implementation, the second reference number and the first reference number are determined based on the number of pixels of the central image and the edge image; for example, in high-precision detection, the pixel of the central image is a1 and the pixel of the edge image is a2: if a1÷4 is a positive integer, the central area image consists of 4 pixels; if a1÷4 is not a positive integer, it is determined whether a1÷3 is a positive integer; if a1÷3 is a positive integer, the central area image consists of 3 pixels; if a1÷3 is not a positive integer, it is determined whether a1÷2 is a positive integer; if a1÷2 is a positive integer, the central area image consists of 2 pixels; if a1÷2 is not a positive integer, the central area image consists of 1 pixel; it can be understood that the method for determining the number of pixels constituting a single edge area image is the same;

[0087] It can be understood that when determining the number of pixel points constituting the surface area image, the maximum number within each precision detection range is used as the starting point.

[0088] It can be understood that the first benchmark number and the second benchmark number are determined respectively according to the detection accuracy to further divide the edge image and the center image into an appropriate number of regional images. This method matches the image segmentation with the detection accuracy, and can better adapt to and meet the needs of detection scenarios with different accuracy requirements, avoiding detection errors caused by unreasonable segmentation. Moreover, through reasonable image cutting rules, it avoids the increase in computational complexity and waste of resources caused by unnecessary fine segmentation or overly coarse segmentation, so that the detection system can maintain efficient operation while meeting the accuracy requirements.

[0089] Specifically, the reference area ratio is the area ratio of the center image to the image on the surface of the punched sheet.

[0090] It can be understood that the reference area ratio is less than 1. In this application, the chipping or deformation is determined based on the edge part of the punching sheet, and the oil stains and rust are determined based on the center part of the punching sheet. Therefore, the area of the center part should be as large as possible, so the reference area ratio is ≥0.8 and the higher the detection accuracy, the larger the value of the reference area ratio; in implementation, for high-precision detection (detection accuracy ≤0.5mm), the reference area ratio is preferably 0.9, for medium-precision detection (0.5mm<detection accuracy ≤2mm), the reference area ratio is preferably 0.85, and for low-precision detection (2mm<detection accuracy), the reference area ratio is preferably 0.8.

[0091] It can be understood that the image segmentation module uses the reference area ratio to divide the edge image and the center image. Since the chipping or deformation is determined based on the edge part and the oil stain and rust are determined based on the center part when detecting the punched sheet, a reasonable reference area ratio can ensure that the area of the center part is large enough, which is conducive to the accurate detection of different types of defects and improves the targeted nature of defect detection.

[0092] Specifically, a machine learning model is preset in the image analysis module to determine the similarity between each fusion region image and the corresponding standard secondary image.

[0093] It is understandable that machine learning models have powerful data analysis capabilities and can quickly and accurately process image data, extract features, and calculate similarities, making them more efficient and accurate than traditional methods. By analyzing the similarity of the fused area images corresponding to the edge area image and the center area image separately, it comprehensively considers the conditions of different parts of the punched film, and can detect both corner defects at the edges and defects in the center (such as oil stains and rust), thus achieving a comprehensive assessment of the punched film quality.

[0094] In implementation, the machine learning model is retrained once a week to ensure the accuracy of its judgment.

[0095] Specifically, the image analysis module determines whether the processed film corresponding to the folder is qualified according to the similarity of the images in each fusion area, including:

[0096] Whether the corresponding punched film has a missing corner is determined based on the similarity between the fused area images corresponding to each edge area image, and whether the corresponding punched film has a defect is determined based on the similarity between the fused area images corresponding to each center area image.

[0097] In implementation, if the similarity between the fused area image and any edge area image is less than a preset similarity, the corresponding punched film is determined to have a missing corner; if the similarity between the fused area image and any center area image is less than a preset similarity, the corresponding punched film is determined to have a defect (oil stain / rust);

[0098] It can be understood that the preset similarity is greater than 70%. The higher the detection accuracy, the greater the preset similarity. Usually: the preset similarity of high-precision detection is ≥85%, the preset similarity of medium-precision detection is ≥80%, and the preset similarity of low-precision detection is ≥75%.

[0099] It is understandable that the workflow and judgment criteria of the entire image analysis module ensure the stability of the quality assessment of the punched film; different batches of production products can be tested according to the same rules, so that product quality is not overly affected by factors such as production batches and environment, ensuring the consistency and stability of product quality, which is conducive to maintaining the company's production reputation and market competitiveness.

[0100] On the other hand, the following combination Figure 3 The punching sheet overlap detection method based on visual monitoring in an embodiment of the present application is described in detail.

[0101] See attached Figure 3, which is a step diagram of a punching sheet overlap detection method based on visual monitoring according to an embodiment of the present application. The present application also provides a punching sheet overlap detection method based on visual monitoring, comprising:

[0102] Step S1, obtaining pressure data and transmission time data of the detection position in real time;

[0103] Step S2, determining whether the punching sheet has reached the detection position based on the pressure data and the transmission time at the detection position;

[0104] Step S3, controlling the transfer platform to stop conveying and controlling the image acquisition module to start image acquisition based on the result of the judgment of reaching the detection position, and controlling the robotic arm to transport the punched sheet to the conveying starting end of the transfer platform;

[0105] Step S4, controlling the transfer table to resume conveyance according to the image acquisition time of the developed film.

[0106] During implementation, steps S1 to S4 are performed consecutively, and between each step S3 and S4, the packaged folder is also sent to the image segmentation module; the image segmentation module divides each punched sheet surface image into several surface area images according to the image cutting rules and generates corresponding secondary numbers; the surface area images with the same secondary number in the folder are fused to form corresponding fused area images; the image analysis module determines the similarity of each fused area image in a single folder to determine whether the punched sheet corresponding to the folder is qualified.

[0107] The above description is only a preferred specific implementation method of the present application and does not limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A punching and lamination detection system based on visual monitoring, characterized in that: include: A mechanical transmission module includes a transfer platform and a mechanical arm, wherein the mechanical arm is used to carry the punched sheet to the transfer starting end of the transfer platform, and the transfer platform is used to transfer the punched sheet from the transfer starting end to the detection position; The image acquisition module includes a fill light unit for providing a plurality of shooting light sources at different angles, an image acquisition unit for acquiring images of the film surface, and a shooting control unit for controlling the fill light unit to sequentially activate the shooting light sources at each angle, controlling the image acquisition unit to acquire images, and packaging a plurality of film surface images of a single film into a folder and generating a primary number for each film surface image according to the image acquisition sequence; a transmission control module, connected to the mechanical transmission module and the image acquisition module, respectively, for controlling the transfer platform to stop transmission and control the image acquisition module to start image acquisition based on the pressure data of the detection position and the transmission time, and controlling the transfer platform to resume transmission based on the image acquisition time; An image segmentation module, connected to the image acquisition module, is used to divide each punched sheet surface image into a plurality of surface region images according to an image segmentation rule and generate corresponding secondary numbers, and fuse the surface region images with the same secondary number in the folder to form a corresponding fused region image; The image segmentation module pre-stores an image segmentation rule, wherein the image segmentation rule includes determining, based on a reference area ratio, to divide each punched sheet surface image into an edge image and a center image, and determining, based on a detection accuracy, a first reference number and a second reference number to respectively segment the edge image and the center image into a first reference number of edge region images and a second reference number of center region images; wherein the central image and the corresponding punched sheet surface image are similar images and the geometric center of the central image is the geometric center of the corresponding punched sheet surface image, and the first reference number is much smaller than the second reference number; The reference area ratio is the area ratio of the center image to the image on the punched sheet surface, and 0.8≤reference area ratio<1; an image analysis module connected to the image segmentation module, for comparing each of the fused region images in a single folder with the corresponding standard secondary image to determine the similarity of each fused region image, and determining whether the corresponding film of the folder is qualified based on the similarity of each fused region image; In which, in a single image acquisition, the number of surface images of the punched film generated is equal to the number of shooting light sources turned on, the surface area image includes a center area image and an edge area image, and the standard secondary image is a surface area image of the punched film standard part at the same position.

2. The system for detecting sheet overlap based on visual monitoring according to claim 1, characterized in that: The detection position is located on the base of the transfer platform, and a pressure sensor for determining pressure data of the transfer platform on the detection position is provided between the detection position and the transfer platform.

3. The punching sheet stacking detection system based on visual monitoring according to claim 1, characterized in that: The transmission control module determines whether the punching sheet reaches the detection position according to the pressure data and transmission time of the detection position, wherein: If the pressure data is within the reference pressure range and the transmission time is within the preset time range, it is determined that the punching sheet has arrived at the detection position; If the pressure data is not within the reference pressure range and / or the transmission time is not within the preset time range, it is determined that the punching sheet has not reached the detection position.

4. The punching sheet stacking detection system based on visual monitoring according to claim 3, characterized in that: The conveying control module controls the transfer table to stop conveying and controls the image acquisition module to start image acquisition according to the result of determining whether the punched sheet has arrived at the detection position; Wherein, controlling the image acquisition module to start image acquisition includes: The shooting control unit controls the fill light unit to sequentially turn on the shooting light sources at various angles and controls the image acquisition unit to perform image acquisition when the shooting light sources at various angles are turned on.

5. The punching sheet stacking detection system based on visual monitoring according to claim 1, characterized in that: The conveying control module determines the end of image acquisition of a single punched sheet according to the image acquisition time of the punched sheet and controls the transfer table to resume conveying, wherein, If the image acquisition time of a single punched sheet is equal to the preset time, it is determined that the image acquisition of the punched sheet is completed and the transfer table is controlled to resume transmission.

6. The punching sheet stacking detection system based on visual monitoring according to claim 1, characterized in that: The image analysis module is preset with a machine learning model to determine the similarity of the images in each fusion area.

7. The punching sheet stacking detection system based on visual monitoring according to claim 1, characterized in that: The image analysis module determines whether the processed film corresponding to the folder is qualified according to the similarity of the images in each fusion area, including: Whether the corresponding punched film has a missing corner is determined based on the similarity between the fused area images corresponding to each edge area image, and whether the corresponding punched film has a defect is determined based on the similarity between the fused area images corresponding to each center area image.

8. A method for detecting lamination overlap based on visual monitoring, using the lamination overlap detection system based on visual monitoring according to any one of claims 1 to 7, characterized in that: include: Step S1, obtaining pressure data and transmission time data of the detection position in real time; Step S2, determining whether the punching sheet has reached the detection position based on the pressure data and the transmission time at the detection position; Step S3, controlling the transfer platform to stop conveying and controlling the image acquisition module to start image acquisition based on the result of the judgment of reaching the detection position, and controlling the robotic arm to transport the punched sheet to the conveying starting end of the transfer platform; Step S4, controlling the transfer table to resume conveyance according to the image acquisition time of the developed film.

Images