Detection method, device and equipment of thin film capacitor and medium

Abstract

The invention relates to the field of image processing, in particular to a thin film capacitor detection method, device and equipment and a medium, the method comprises the following steps: acquiring a first image and a standard image of a thin film capacitor acquired by an X-ray imaging system, the first image and the standard image having the same X-ray intensity; determining the similarity between the first image and the standard image; if the similarity is smaller than a preset similarity threshold value, an X-ray image sequence of the thin film capacitor is obtained, and the X-ray image sequence sequentially comprises a plurality of second images with the X-ray intensities from small to large; determining a potential difference area of the thin film capacitor according to the second image of the adjacent X-ray intensity; for each potential difference area, determining a third image in the second image corresponding to the potential difference area; and performing anomaly detection on the third image to obtain a first detection result. According to the invention, the detection efficiency and accuracy can be improved.

Description

Technical Field

[0001] The present application relates to the field of image processing, and in particular to a method, device, equipment and medium for detecting a thin film capacitor. Background Art

[0002] Film capacitors, as a prominent product in the field of electronic components, are widely used in various electronic devices, and undertake key functions such as energy storage and filtering. With the rapid development of technology, the size of electronic devices is getting smaller and smaller, but the performance requirements are becoming more and more stringent, which poses unprecedented challenges to the quality and reliability of film capacitors.

[0003] Film capacitors include metallized film, lead electrodes, insulating medium and shell. At present, the detection methods for film capacitors are relatively simple and mainly rely on visual inspection systems. These systems capture the appearance images of capacitors through high-resolution cameras and use advanced image processing algorithms to analyze the images in detail to identify possible scratches, stains, deformation and other defects on the surface of the capacitors. However, the accuracy of detecting capacitor defects is insufficient and only surface defects can be detected. For internal defects, the relevant technology still relies on manual inspection and sampling inspection for a certain batch, which has low inspection efficiency and low inspection accuracy. Summary of the invention

[0004] The purpose of this application is to provide a method, device, equipment and medium for detecting a thin film capacitor, which can improve detection efficiency and accuracy.

[0005] In a first aspect, a method for detecting a film capacitor is provided, comprising: Acquire a first image and a standard image of the thin film capacitor acquired by an X-ray imaging system, wherein the X-ray intensity of the first image and the standard image is the same; Determining a similarity between the first image and the standard image; If the similarity is less than a preset similarity threshold, acquiring an X-ray image sequence of the thin film capacitor, wherein the X-ray image sequence sequentially includes a plurality of second images with increasing X-ray intensities; determining a potential difference region of the thin film capacitor based on a second image of adjacent X-ray intensities; For each potential difference region, determine a third image from the second image corresponding to the potential difference region; Anomaly detection is performed on the third image to obtain a first detection result.

[0006] Through the above technical solution, a first image and a standard image of a thin film capacitor under the same X-ray intensity conditions collected by an X-ray imaging system are obtained; by determining the similarity between the first image and the standard image, a preliminary judgment can be made as to whether there is an abnormality in the capacitor; if the similarity is lower than a preset threshold, a sequence of X-ray images is further obtained for detailed analysis. This progressive detection method is both efficient and accurate, avoids unnecessary comprehensive detection, and improves detection efficiency and accuracy.

[0007] In an achievable manner, the acquiring of the X-ray image sequence of the thin film capacitor includes: acquiring an initial X-ray image sequence of the thin film capacitor, the initial X-ray image sequence sequentially including a plurality of initial second images with increasing X-ray intensity from small to large; For each initial second image, obtaining an outer packaging X-ray image of the outer packaging of the film capacitor at the X-ray intensity corresponding to the initial second image; removing the outer packaging information in the initial second image according to the outer packaging X-ray image to obtain a second image corresponding to the initial second image; After the outer packaging information of all the initial second images is removed, a plurality of second images are obtained, forming an X-ray image sequence of the thin film capacitor.

[0008] Through the above technical solution, when acquiring an X-ray image sequence, the initial X-ray image sequence is first acquired, and the outer packaging information is removed for each initial second image, thereby effectively eliminating the influence of the outer packaging on the internal detection and providing clear and interference-free image data for the subsequent determination of potential difference areas.

[0009] In one achievable manner, determining the potential difference area of ​​the thin film capacitor according to the second image of adjacent X-ray intensities includes: Identifying a first feature point of a first target image and a second feature point of a second target image in the second image of adjacent X-ray intensities; Perform feature point matching according to the descriptor of the first feature point and the descriptor of the second feature point to determine a successfully matched feature point pair; Aligning the first target image and the second target image according to the successfully matched feature point pairs; Calculate the grayscale difference of each pixel of the first target image and the second target image after registration to obtain a difference image; Obtaining a binary image using a grayscale difference threshold according to the difference image; A potential difference region of the thin film capacitor is determined according to the binarized image.

[0010] Through the above technical solution, when determining the potential difference area, the feature points in the adjacent X-ray intensity second image are identified and matched, the images are aligned and the grayscale difference is calculated to obtain the difference image; the difference image is binarized using the grayscale difference threshold, so as to clearly identify the potential difference area, which not only improves the accuracy of detection, but also effectively reduces the possibility of false alarms and missed alarms.

[0011] In an achievable manner, before obtaining a binary image using a grayscale difference threshold according to the difference image, the method further includes: Determine the local mean and local standard deviation of the window corresponding to each pixel point of the difference image; The grayscale difference threshold corresponding to each pixel is determined according to the local mean and local standard deviation of the window corresponding to each pixel.

[0012] Through the above technical solution, the local mean and local standard deviation of the window corresponding to each pixel point of the difference image are calculated. According to the local mean and local standard deviation, the threshold is dynamically adjusted to adapt to the feature changes in different areas, thereby further improving the accuracy and reliability of the binary image.

[0013] In one achievable manner, the present invention further includes: Acquiring a CCD image of the thin film capacitor; Performing appearance inspection on the thin film capacitor according to the CCD image to obtain a second inspection result; If the second detection result is that the appearance of the film capacitor is abnormal, a prompt message is generated, and the prompt message includes the abnormal type and the abnormal location.

[0014] Through the above technical solution, an appearance inspection link is added. By acquiring the CCD image of the thin film capacitor and performing appearance inspection, abnormal phenomena on the surface of the capacitor can be discovered in time. When the appearance inspection result is abnormal, prompt information is generated in time.

[0015] In one achievable manner, if the second detection result is that the film capacitor has an appearance abnormality, the abnormality type is bulging, and the first detection result is an internal abnormality, the method further includes: Acquire a first position information point set of the positioning mark of the third image in the X-ray coordinate system, and a second position information point set of the positioning mark of the CCD image in the CCD coordinate system; registering the third image with the CCD image according to the first position information point set and the second position information point set; According to the potential difference area of ​​the registered third image and the area corresponding to the potential difference area in the registered CCD image, comprehensive abnormality information of the thin film capacitor is determined, and the comprehensive abnormality information includes: abnormality type and abnormality position.

[0016] Through the above technical scheme, when a bulge is found during appearance inspection and an abnormality is found during internal inspection, the third image and the CCD image are registered, and the comprehensive abnormality information is determined by combining the information of the potential difference area and the corresponding area; an organic combination of the internal and appearance inspection results is achieved, providing maintenance personnel with more comprehensive and accurate abnormality information, which helps to quickly locate the problem.

[0017] In one achievable manner, performing abnormality detection on the third image to obtain a first detection result includes: Perform bubble detection according to the third image to obtain a first sub-inspection result; Perform crack detection according to the third image to obtain a second sub-inspection result; Perform impurity detection according to the third image to obtain a third sub-inspection result; A first inspection result is determined according to the first sub-inspection result, the second sub-inspection result, and the third sub-inspection result.

[0018] Through the above technical solution, when performing abnormality detection on the third image, bubbles, cracks and impurities are detected respectively, and the first inspection result is comprehensively determined based on the detection results, thereby improving the accuracy and comprehensiveness of the detection.

[0019] In a second aspect, a detection device for a film capacitor is provided, comprising: An acquisition module, used to acquire a first image and a standard image of the thin film capacitor acquired by an X-ray imaging system, wherein the X-ray intensity of the first image and the standard image is the same; A similarity determination module, used to determine the similarity between the first image and the standard image; The acquisition module is further used to acquire an X-ray image sequence of the thin film capacitor if the similarity is less than a preset similarity threshold, wherein the X-ray image sequence sequentially includes a plurality of second images with X-ray intensities from small to large; A potential difference region determination module, used for determining the potential difference region of the thin film capacitor according to the adjacent second image of X-ray intensity; A third image determination module, configured to determine, for each potential difference region, a third image from the second image corresponding to the potential difference region; The abnormality detection module is used to perform abnormality detection on the third image to obtain a first detection result.

[0020] In a third aspect, an electronic device is provided, the electronic device comprising: one or more processors; Memory; One or more applications, wherein one or more applications are stored in a memory and configured to be executed by one or more processors, and one or more programs are configured to: perform operations corresponding to the method shown in any possible implementation of the first aspect.

[0021] In a fourth aspect, a computer-readable storage medium is provided, wherein the storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, at least one program, a code set or an instruction set is loaded and executed by a processor to implement a method as shown in any possible implementation method of the first aspect.

[0022] According to a fifth aspect, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, the method is implemented as shown in any possible implementation manner in the first aspect.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. The first image and the standard image of the thin film capacitor under the same X-ray intensity conditions collected by the X-ray imaging system are obtained; by determining the similarity between the first image and the standard image, it is possible to preliminarily determine whether the capacitor has an abnormality; if the similarity is lower than a preset threshold, a further X-ray image sequence is obtained for detailed analysis. This progressive detection method is both efficient and accurate, avoiding unnecessary comprehensive detection and improving detection efficiency.

[0024] 2. When acquiring the X-ray image sequence, first acquire the initial X-ray image sequence, and remove the outer packaging information for each initial second image, effectively eliminating the influence of the outer packaging on the internal detection, and providing clear and interference-free image data for the subsequent determination of potential difference areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of a method for detecting a thin film capacitor provided in an embodiment of the present application; Figure 2 It is a flow chart of a detection process of a thin film capacitor provided in an embodiment of the present application; Figure 3 It is a structural schematic diagram of a thin film capacitor detection device provided in an embodiment of the present application; Figure 4 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally means that the associated objects before and after are in an "or" relationship.

[0029] Specifically, the present application provides a method for detecting a thin film capacitor, such as Figure 1 As shown, the method provided in the embodiment of the present application can be executed by an electronic device, which can be a server or a terminal device, wherein the server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services. The terminal device can be a smart phone, a tablet computer, a laptop computer, a desktop computer, etc., but is not limited thereto. The terminal device and the server can be directly or indirectly connected via wired or wireless communication, which is not limited in the embodiment of the present application. The method includes: S101, acquiring a first image and a standard image of a thin film capacitor acquired by an X-ray imaging system; The X-ray intensity of the first image and the standard image is the same; Among them, the X-ray imaging system is a device that uses X-rays for imaging, which can generate an internal structure image of the film capacitor by emitting X-rays and capturing the attenuation of the X-rays after penetrating the object. The first image and the standard image are both used to represent the image of the film capacitor collected by the X-ray imaging system. Among them, the first image refers to the current image to be analyzed, and the standard image refers to a defect-free standard reference image. The standard image is an image of a capacitor with the same model, size, etc. as the current film capacitor, and the X-ray intensity of the two is the same.

[0030] On the film capacitor production line, quality inspection can be performed, specifically, the quality of the film capacitor can be determined by the inspection method provided in the embodiment of the present application. X-ray imaging inspection is a non-destructive inspection method that can intuitively display the internal structure of the capacitor. Specifically, when the capacitor is produced, the robot arm / transmission device on the automated production line is used to place it under the X-ray imaging system, adjust the X-ray intensity to a predetermined value, and acquire a first image. The predetermined value can be set by a technician based on experience, and the embodiment of the present application is no longer limited. For standard images, the capacitor image corresponding to the current film capacitor can be called from the database.

[0031] S102, determining the similarity between the first image and the standard image; The similarity is used to measure the similarity between two images. In the quality inspection of thin film capacitors, the image of a defect-free capacitor is used as the standard image, and the similarity between the first image currently acquired and the standard image is calculated; if the similarity is high, it means that the current capacitor is likely to be defect-free; if the similarity is low, it may indicate that the capacitor has defects.

[0032] It should be noted that when performing similarity calculation, the first image and the standard image need to be registered and the background image needs to be removed. At the same time, the image acquisition environment and camera parameters of the two images are the same.

[0033] In some possible cases, the first image and the standard image may be preprocessed, such as denoising, contrast enhancement, etc., to improve the image quality, and then similarity calculation is performed. In one achievable manner, key features such as edges, textures, shapes, etc. in the first image and the standard image are extracted to reflect the internal structure or appearance state of the capacitor; the features in the first image are matched with the features in the standard image using feature matching algorithms such as SIFT (scale-invariant feature transform) and SURF (speeded-up robust features); the similarity of the two images is evaluated based on the number of feature point matches. In another achievable manner, histogram equalization is performed on the first image and the standard image respectively; SSIM (structural similarity index) or MSE (mean square error) is used to calculate the similarity between the first image and the standard image. It is understandable that other methods may also be used to determine the similarity, which is not limited here.

[0034] In this step, by comparing the similarity between the currently acquired image and the standard image, it is possible to preliminarily determine whether the capacitor has defects or abnormalities; if there is no abnormality, the test result is determined to be normal; if it is determined that there is an abnormality, it is necessary to further determine whether there is an abnormality and the abnormal situation according to S103-S106; the detection accuracy and detection effect can be greatly improved.

[0035] S103, if the similarity is less than a preset similarity threshold, obtaining an X-ray image sequence of the thin film capacitor, The X-ray image sequence includes a plurality of second images with increasing X-ray intensities in sequence; The preset similarity threshold is a pre-set value that can be set by the user according to actual needs. For example, it can be 90%, 95%, or 98%, which is used to determine whether the similarity between the current image and the standard image meets the quality requirements. If the similarity is lower than the threshold, it is considered that there is a difference between the current image and the standard image, and further verification is required to determine whether there are defects. If the similarity is not less than the threshold, it is considered that the current image is the same as the standard image and there are no defects.

[0036] The second image is a single image in the X-ray image sequence. Multiple second images sequentially show the internal structure of the capacitor under gradually increasing X-ray intensities. By comparing these images, changes in the internal structure of the capacitor can be determined, thereby judging whether it has defects.

[0037] The X-ray image sequence can show the internal structure of the capacitor under different X-ray intensities, and the settings for a series of X-ray intensities can be set by the user based on experience. Specifically, for each type of film capacitor, the technician will set multiple groups of X-ray intensities according to the film capacitor, and then collect and compare images, and then determine a series of X-ray intensities corresponding to each type of film capacitor; and build a correspondence between the type and the X-ray intensity series. Therefore, in an embodiment of the present application, the type of the current film capacitor is determined, and the corresponding X-ray intensity series is determined based on the type of the current film capacitor and the corresponding relationship; then based on the X-ray intensity series, the X-ray imaging system is controlled to collect the X-ray image sequence of the film capacitor, so as to obtain the X-ray image sequence of the film capacitor. Specifically, the X-ray intensity of the X-ray imaging system is automatically adjusted to obtain the first second image at a lower X-ray intensity; the X-ray intensity is gradually increased, and subsequent second images are collected in sequence until the predetermined X-ray intensity range is reached; all collected second images are arranged in order from small to large in X-ray intensity to form an X-ray image sequence.

[0038] S104, determining a potential difference area of ​​the thin film capacitor according to the second image of adjacent X-ray intensities; The second images of adjacent X-ray intensities are any two images that are adjacent in X-ray intensity, and the X-ray intensity of the previous image is less than the X-ray intensity of the latter image, showing the internal structure of the capacitor under different X-ray penetration capabilities.

[0039] The potential difference area refers to the difference or change area in the internal structure of the capacitor that appears in adjacent X-ray images due to the change in X-ray intensity, which may reflect defects inside the capacitor, such as bubbles, cracks, and impurities.

[0040] S105, for each potential difference region, determining a third image from the second image corresponding to the potential difference region; The third image refers to an image selected from the second images corresponding to the potential difference region. The third image may be an image with the highest definition among the second images corresponding to the potential difference region.

[0041] S106: Perform abnormality detection on the third image to obtain a first detection result.

[0042] After obtaining the third image corresponding to each potential difference area, if there is one potential difference area, directly perform anomaly detection on the third image to determine its defect type and location. If there are at least two potential difference areas, determine the distance between the potential difference areas, and if the distance is less than the distance threshold, determine that the two potential difference areas need to be merged. The distance threshold technician can set according to actual needs or experience; if the distance is not less than the distance threshold, no merging is required. After determining the potential difference areas that need to be merged, the potential difference areas are fused according to the third images corresponding to the potential difference areas that need to be merged; when fusion is performed, one of the third images can be adjusted according to the difference in the pixel means of the non-difference areas, and then fused to retain more details.

[0043] Exemplarily, for a thin film capacitor, photographing is performed according to a first x-ray intensity, a second x-ray intensity, a third x-ray intensity, and a fourth x-ray intensity to obtain a first image, a second image, a third image, and a fourth image; the first x-ray intensity is less than the second x-ray intensity, which is less than the third x-ray intensity, which is less than the fourth x-ray intensity; then the first image and the second image are compared to obtain a first potential difference area; the second image and the third image are compared to obtain a second potential difference area; at this time, the ranges of the first potential difference area and the second potential difference area are not close, and the fault types such as bubbles, cracks, and impurities can be calculated based on the first potential difference area respectively; if the ranges of the first potential difference area and the second potential difference area are close, it may be the same fault type such as bubbles, and the first potential difference area and the second potential difference area may be merged, and then the images corresponding to the two areas are used to jointly determine the difference type.

[0044] It can be seen that in the embodiment of the present application, the first image and the standard image of the thin film capacitor under the same X-ray intensity conditions collected by the X-ray imaging system are obtained; by determining the similarity between the first image and the standard image, it is possible to preliminarily judge whether there is an abnormality in the capacitor; if the similarity is lower than the preset threshold, the X-ray image sequence is further obtained for detailed analysis. This progressive detection method is both efficient and accurate, avoids unnecessary comprehensive detection, and improves detection efficiency.

[0045] Furthermore, the third image is detected for abnormalities to obtain a first detection result, including: performing bubble detection based on the third image to obtain a first sub-inspection result; performing crack detection based on the third image to obtain a second sub-inspection result; performing impurity detection based on the third image to obtain a third sub-inspection result; and determining the first inspection result based on the first sub-inspection result, the second sub-inspection result and the third sub-inspection result.

[0046] Among them, bubbles usually appear as circular or elliptical bright areas in the image, cracks appear as thin and long dark lines or broken areas, and impurities appear as bright spots, dark spots or irregular shapes in the image. Therefore, feature information in the third image is extracted, and the extracted bubble features are compared with the preset bubble feature library to determine whether bubbles exist and the number, size and location of the bubbles; the extracted crack features are classified using a classification algorithm to determine the type, length and severity of the cracks; and the number and distribution of impurities are determined through threshold segmentation, cluster analysis and other algorithms, so as to obtain the first inspection result.

[0047] Of course, for the quality assessment of film capacitors, whether they are qualified products can be further determined according to user requirements.

[0048] Furthermore, the film capacitor has an outer packaging, which is easy to cause noise influence on X-ray imaging. Therefore, the noise can be removed to better identify the internal structure. The X-ray image sequence of the film capacitor is obtained, including: An initial X-ray image sequence of a thin film capacitor is obtained, the initial X-ray image sequence sequentially including a plurality of initial second images with X-ray intensities from small to large; for each initial second image, an outer packaging X-ray image of the outer packaging of the thin film capacitor is obtained at the X-ray intensity corresponding to the initial second image; the outer packaging information in the initial second image is removed according to the outer packaging X-ray image to obtain a second image corresponding to the initial second image; after the outer packaging information of all the initial second images is removed, a plurality of second images are obtained to form an X-ray image sequence of the thin film capacitor.

[0049] The initial X-ray image sequence refers to a set of images of the film capacitor at different X-ray intensities directly acquired by X-ray imaging. The initial second image refers to a single image in the initial X-ray image sequence. The outer packaging refers to the packaging material outside the film capacitor, and accordingly, the outer packaging X-ray image refers to an X-ray image that only contains the outer packaging information of the film capacitor at the X-ray intensity.

[0050] Specifically, the grayscale values ​​of each pixel of the initial first image and the outer packaging X-ray image are converted into corresponding energy matrices, and the matrix difference between the initial first image and the outer packaging X-ray image is calculated, and the matrix difference is converted into corresponding grayscale values ​​to obtain grayscale images to obtain multiple second images. The influence of the outer packaging on the image is eliminated through the energy matrix, making the second image more accurate and more conducive to the detection of capacitors.

[0051] Furthermore, based on the second image of the adjacent X-ray intensity, the potential difference area of ​​the thin film capacitor is determined, including: identifying the first feature point of the first target image in the second image of the adjacent X-ray intensity, and the second feature point of the second target image; matching the feature points according to the descriptor of the first feature point and the descriptor of the second feature point, and determining the successfully matched feature point pair; aligning the first target image and the second target image according to the successfully matched feature point pair; calculating the grayscale difference of each pixel point of the first target image and the second target image after the alignment to obtain a difference image; obtaining a binarized image based on the difference image using a grayscale difference threshold; and determining the potential difference area of ​​the thin film capacitor based on the binarized image.

[0052] In an embodiment of the present application, the second image of adjacent X-ray intensities includes a first target image and a second target image. In the first target image and the second target image, a feature point detection algorithm is used to identify key feature points, such as edges, corners, etc. Descriptors are calculated for each feature point, and the feature points in the first target image are matched with the feature points in the second target image by comparing the similarity of the descriptors (such as using Euclidean distance, Hamming distance, etc.), and the successfully matched feature point pairs represent the same or similar structural points in the two images. Using the successfully matched feature point pairs, the first target image is aligned with the second target image through a transformation matrix (such as affine transformation, perspective transformation, etc.). The purpose of alignment is to ensure that the same structural points in the two images are consistent in spatial position. In the registered image, the grayscale value difference of each pixel is calculated to obtain a difference image, wherein each pixel value in the different image represents the grayscale difference between the two images at that position. The pixel values ​​in the difference image are binarized according to the threshold, and the pixel values ​​greater than the threshold are set to white, and the pixel values ​​less than or equal to the threshold are set to black, and the white area represents the area where the film capacitor may have differences. Morphological operations (such as erosion, dilation, opening and closing) are performed on the binary image to remove small isolated points and fill small holes to obtain potential difference areas.

[0053] Furthermore, before obtaining a binary image by using a grayscale difference threshold according to the difference image, the method further includes: Determine the local mean and local standard deviation of the window corresponding to each pixel of the difference image; The grayscale difference threshold corresponding to each pixel is determined according to the local mean and local standard deviation of the window corresponding to each pixel.

[0054] In the embodiment of the present application, when calculating the binarization threshold of each pixel in the difference image, a dynamic threshold method based on local statistical characteristics can be used.

[0055] Specifically, the local mean and standard deviation of each pixel are calculated, and a threshold is dynamically calculated for each pixel based on the local mean and standard deviation.

[0056] For each pixel (i, j) in the difference image, we define a small window W(i, j) centered on the pixel. The size of the window can be selected as needed (e.g. 3x3, 5x5, etc.). The calculation formula for the local mean μ(i, j) is: , where I(x,y) is the pixel value at coordinate (x,y) in the difference image, is the number of pixels in window W(i,j).

[0057] The calculation formula of local standard deviation σ(i,j) is: .

[0058] According to the local mean μ(i,j) and the local standard deviation σ(i,j), a threshold T(i,j) is dynamically calculated for each pixel. Specifically, T(i,j)=μ(i,j)+α×σ(i,j), where α is an adjustable parameter that can be customized by the user.

[0059] For further information, see Figure 2 , further comprising: acquiring a CCD image of the thin film capacitor; performing an appearance inspection on the thin film capacitor according to the CCD image to obtain a second inspection result; if the second inspection result is that the appearance of the thin film capacitor is abnormal, generating prompt information, the prompt information including the abnormal type and the abnormal location.

[0060] In the embodiment of the present application, the CCD image specifically refers to an image of the thin film capacitor taken by a CCD camera, and its shooting angle should be the same as that of the first image.

[0061] The second test result refers to the evaluation result of the appearance quality of the film capacitor obtained through appearance inspection, including the abnormality type and abnormality location.

[0062] For appearance inspection, appearance abnormalities include but are not limited to: bulging, cracks, scratches, dents, unclear markings. Bulging may be caused by internal cracks, impurities, etc., among which cracks may be caused by the electrolytic paper of the guide needle type film capacitor being pierced.

[0063] In an embodiment of the present application, an abnormality recognition network model is used to automatically classify and identify the position of CCD images. Specifically, a large number of CCD images of thin film capacitors are obtained as training data, and the abnormal types and positions therein are marked; the training data are learned and trained using the initial model to obtain an abnormality recognition network model. The CCD image of the thin film capacitor is input into the abnormality recognition network model for prediction. If the prediction result is abnormal, a prompt information containing the abnormality type and location is generated according to the output of the model.

[0064] Further, if the second detection result is that the film capacitor has an appearance abnormality, the abnormality type is bulging, and the first detection result is an internal abnormality, the method further includes: Acquire a first position information point set of the positioning mark of the third image in the X-ray coordinate system, and a second position information point set of the positioning mark of the CCD image in the CCD coordinate system; registering the third image with the CCD image according to the first position information point set and the second position information point set; According to the potential difference area of ​​the registered third image and the area corresponding to the potential difference area in the registered CCD image, comprehensive abnormality information of the thin film capacitor is determined, and the comprehensive abnormality information includes: abnormality type and abnormal position.

[0065] Among them, if the abnormality type is bulging, it is possible that the electrolytic paper of the guide needle type film capacitor is punctured and the situation is relatively serious. Of course, there may be other situations, which require further verification. Therefore, according to the first position information point set and the second position information point set, the third image and the CCD image are aligned; according to the position and shape of the potential difference area in the third image, the corresponding area is found in the aligned CCD image; combined with the internal and external inspection results, the comprehensive abnormal information of the film capacitor is determined, including the abnormality type and abnormal position.

[0066] Specifically, in a process of determining comprehensive abnormality information, in one achievable manner, based on the potential difference area of ​​the third image after registration and the area corresponding to the potential difference area in the CCD image after registration, an image is sent to a technician's client device so that the technician can check and confirm the abnormality type and abnormality location; the information fed back by the technician's client device is received as the comprehensive abnormality information of the area. In another achievable manner, based on the potential difference area of ​​the third image after registration and the area corresponding to the potential difference area in the CCD image after registration, a recognition model is used for detection to determine the comprehensive abnormality information of the thin film capacitor, wherein the recognition model is trained based on multiple x-ray images and multiple CCD images, and each pair of x-ray images and CCD images is marked with abnormality type and abnormal location.

[0067] Furthermore, after determining the comprehensive abnormal information of the film capacitor, an abnormality report can be generated, including the abnormality type, abnormality location, possible fault cause and recommended repair measures, so as to guide technicians to locate and solve the problem quickly and accurately.

[0068] The present application provides a detection device for a thin film capacitor, see Figure 3 ,include: An acquisition module 210 is used to acquire a first image and a standard image of the thin film capacitor acquired by an X-ray imaging system, wherein the X-ray intensity of the first image and the standard image is the same; A similarity determination module 220, configured to determine the similarity between the first image and the standard image; The acquisition module 210 is further configured to acquire an X-ray image sequence of the thin film capacitor if the similarity is less than a preset similarity threshold, wherein the X-ray image sequence sequentially includes a plurality of second images with increasing X-ray intensities; A potential difference region determination module 230, for determining a potential difference region of the thin film capacitor according to the second image of adjacent X-ray intensities; A third image determining module 240 is used to determine, for each potential difference region, a third image from the second image corresponding to the potential difference region; The abnormality detection module 250 is used to perform abnormality detection on the third image to obtain a first detection result.

[0069] In an achievable manner, the acquisition module 210 is further used to: acquire an initial X-ray image sequence of the thin film capacitor, the initial X-ray image sequence sequentially including a plurality of initial second images with increasing X-ray intensity from small to large; For each initial second image, an outer packaging X-ray image of the outer packaging of the film capacitor at the X-ray intensity corresponding to the initial second image is obtained; and the outer packaging information in the initial second image is removed according to the outer packaging X-ray image to obtain a second image corresponding to the initial second image; After the outer packaging information of all the initial second images is removed, a plurality of second images are obtained to form an X-ray image sequence of the thin film capacitor.

[0070] In one practicable manner, the potential difference area determination module 230 is used to: identifying a first feature point of a first target image in a second image of adjacent X-ray intensities and a second feature point of a second target image; Perform feature point matching based on the descriptor of the first feature point and the descriptor of the second feature point to determine a successfully matched feature point pair; Aligning the first target image and the second target image according to the successfully matched feature point pairs; Calculate the grayscale difference of each pixel of the first target image and the second target image after registration to obtain a difference image; According to the difference image, a binary image is obtained by using the grayscale difference threshold; Determine the potential difference areas of thin film capacitors based on the binarized images.

[0071] In one achievable manner, the present invention further includes: A threshold determination module, used to determine the local mean and local standard deviation of the window corresponding to each pixel point of the difference image; The grayscale difference threshold corresponding to each pixel is determined according to the local mean and local standard deviation of the window corresponding to each pixel.

[0072] In one achievable manner, the present invention further includes: CCD image detection module, used to: obtain CCD image of thin film capacitor; Performing appearance inspection on the thin film capacitor according to the CCD image to obtain a second inspection result; If the second detection result is that the appearance of the film capacitor is abnormal, a prompt message is generated, and the prompt message includes the abnormal type and the abnormal location.

[0073] In one achievable manner, if the second detection result is that the film capacitor has an appearance abnormality, the abnormality type is bulging, and the first detection result is an internal abnormality, the device further includes: The comprehensive detection module is used to obtain a first position information point set of the positioning mark of the third image in the X-ray coordinate system and a second position information point set of the positioning mark of the CCD image in the CCD coordinate system; registering the third image with the CCD image according to the first position information point set and the second position information point set; According to the potential difference area of ​​the registered third image and the area corresponding to the potential difference area in the registered CCD image, comprehensive abnormality information of the thin film capacitor is determined, and the comprehensive abnormality information includes: abnormality type and abnormal position.

[0074] In one achievable manner, the anomaly detection module 250 is used to: Perform bubble detection according to the third image to obtain a first sub-inspection result; Perform crack detection according to the third image to obtain a second sub-inspection result; Perform impurity detection according to the third image to obtain a third sub-inspection result; A first inspection result is determined according to the first sub-inspection result, the second sub-inspection result, and the third sub-inspection result.

[0075] An electronic device is provided in an embodiment of the present application, such as Figure 4As shown, Figure 4 The electronic device 300 shown includes: a processor 301 and a memory 303. The processor 301 and the memory 303 are connected, such as through a bus 302. Optionally, the electronic device 300 may also include a transceiver 304. It should be noted that in actual applications, the transceiver 304 is not limited to one, and the structure of the electronic device 300 does not constitute a limitation on the embodiments of the present application.

[0076] The processor 301 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processor 301 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0077] The bus 302 may include a path to transmit information between the above components. The bus 302 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The bus 302 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0078] The memory 303 may be a ROM (Read Only Memory) or other types of static storage devices that can store static information and instructions, a RAM (Random Access Memory) or other types of dynamic storage devices that can store information and instructions, or an EEPROM (Electrically Erasable Programmable Read Only Memory), a CD-ROM (Compact Disc Read Only Memory) or other optical disk storage, optical disk storage (including compressed optical disk, laser disk, optical disk, digital versatile disk, Blu-ray disk, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto.

[0079] The memory 303 is used to store the application code for executing the solution of the present application, and the execution is controlled by the processor 301. The processor 301 is used to execute the application code stored in the memory 303 to implement the contents shown in the above method embodiment.

[0080] Among them, electronic devices include but are not limited to: mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 4 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0081] An embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer-readable storage medium is run on a computer, the computer can execute the corresponding content in the aforementioned method embodiment.

[0082] An embodiment of the present application provides a computer program product, including a computer program, which implements the corresponding contents of the aforementioned method embodiment when the computer program is executed by a processor.

[0083] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0084] The above are only some implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for detecting a film capacitor, characterized in that: include: Acquire a first image and a standard image of the thin film capacitor acquired by an X-ray imaging system, wherein the X-ray intensity of the first image and the standard image is the same; Determining a similarity between the first image and the standard image; If the similarity is less than a preset similarity threshold, acquiring an X-ray image sequence of the thin film capacitor, wherein the X-ray image sequence sequentially includes a plurality of second images with increasing X-ray intensities; determining a potential difference region of the thin film capacitor based on a second image of adjacent X-ray intensities; For each potential difference region, determine a third image from the second image corresponding to the potential difference region; Anomaly detection is performed on the third image to obtain a first detection result.

2. The method for detecting a film capacitor according to claim 1, characterized in that: The step of acquiring the X-ray image sequence of the thin film capacitor comprises: acquiring an initial X-ray image sequence of the thin film capacitor, wherein the initial X-ray image sequence sequentially comprises a plurality of initial second images with increasing X-ray intensity from small to large; For each initial second image, obtaining an outer packaging X-ray image of the outer packaging of the film capacitor at the X-ray intensity corresponding to the initial second image; removing the outer packaging information in the initial second image according to the outer packaging X-ray image to obtain a second image corresponding to the initial second image; After the outer packaging information of all the initial second images is removed, a plurality of second images are obtained, forming an X-ray image sequence of the thin film capacitor.

3. The method for detecting a film capacitor according to claim 1, characterized in that: Determining a potential difference area of ​​the thin film capacitor according to the second image of adjacent X-ray intensities includes: Identifying a first feature point of a first target image and a second feature point of a second target image in the second image of adjacent X-ray intensities; Perform feature point matching according to the descriptor of the first feature point and the descriptor of the second feature point to determine a successfully matched feature point pair; Aligning the first target image and the second target image according to the successfully matched feature point pairs; Calculate the grayscale difference of each pixel of the first target image and the second target image after registration to obtain a difference image; Obtaining a binary image using a grayscale difference threshold according to the difference image; A potential difference region of the thin film capacitor is determined according to the binarized image.

4. The method for detecting a film capacitor according to claim 3, characterized in that: Before obtaining a binary image using a grayscale difference threshold according to the difference image, the method further includes: Determine the local mean and local standard deviation of the window corresponding to each pixel point of the difference image; The grayscale difference threshold corresponding to each pixel is determined according to the local mean and local standard deviation of the window corresponding to each pixel.

5. The method for detecting a film capacitor according to claim 1, characterized in that: Also includes: Acquiring a CCD image of the thin film capacitor; Performing appearance inspection on the thin film capacitor according to the CCD image to obtain a second inspection result; If the second detection result is that the appearance of the film capacitor is abnormal, a prompt message is generated, and the prompt message includes the abnormal type and the abnormal location.

6. The method for detecting a film capacitor according to claim 5, characterized in that: If the second detection result is that the film capacitor has an appearance abnormality, the abnormality type is bulging, and the first detection result is an internal abnormality, the method further includes: Acquire a first position information point set of the positioning mark of the third image in the X-ray coordinate system, and a second position information point set of the positioning mark of the CCD image in the CCD coordinate system; registering the third image with the CCD image according to the first position information point set and the second position information point set; According to the potential difference area of ​​the registered third image and the area corresponding to the potential difference area in the registered CCD image, comprehensive abnormality information of the thin film capacitor is determined, and the comprehensive abnormality information includes: abnormality type and abnormality position.

7. The method for detecting a film capacitor according to claim 1, characterized in that: The performing abnormality detection on the third image to obtain a first detection result includes: Perform bubble detection according to the third image to obtain a first sub-inspection result; Perform crack detection according to the third image to obtain a second sub-inspection result; Perform impurity detection according to the third image to obtain a third sub-inspection result; A first inspection result is determined according to the first sub-inspection result, the second sub-inspection result, and the third sub-inspection result.

8. A film capacitor detection device, characterized in that: include: An acquisition module, used to acquire a first image and a standard image of the thin film capacitor acquired by an X-ray imaging system, wherein the X-ray intensity of the first image and the standard image is the same; A similarity determination module, used to determine the similarity between the first image and the standard image; The acquisition module is further used to acquire an X-ray image sequence of the thin film capacitor if the similarity is less than a preset similarity threshold, wherein the X-ray image sequence sequentially includes a plurality of second images with X-ray intensities from small to large; A potential difference region determination module, used for determining the potential difference region of the thin film capacitor according to the adjacent second image of X-ray intensity; A third image determination module, configured to determine, for each potential difference region, a third image from the second image corresponding to the potential difference region; The abnormality detection module is used to perform abnormality detection on the third image to obtain a first detection result.

9. An electronic device, characterized in that: include: one or more processors; Memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, and the one or more applications are configured to: execute the steps of the thin film capacitor detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The storage medium stores at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded by the processor and executes the steps of the thin film capacitor detection method according to any one of claims 1 to 7.

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