Material strip hole detection system and method

Abstract

A material strip hole detection system (200) and method. The detection system (200) comprises a light source assembly (210), at least one camera (220), and an image processing unit (230), wherein the light source assembly (210) is configured to emit light towards a first surface of a material strip; during spot inspection, the light source assembly (210) emits light towards a spot inspection sheet carried by the material strip; the photographing direction of the at least one camera (220) is oriented towards a second surface of the material strip; the at least one camera (220) is used for imaging the spot inspection sheet illuminated by the light source assembly (210); the image processing unit (230) is configured to measure size information of holes in the spot inspection sheet on the basis of an image under inspection of the spot inspection sheet obtained by means of the imaging, so as to determine whether the spot inspection is successful; the camera (220) is further used for imaging, when the spot inspection is successful, the material strip illuminated by the light source assembly (210); and the image processing unit (230) is further configured to measure size information of holes in the material strip on the basis of an image under inspection of the material strip obtained by each camera (220).

Description

Material strip hole detection system and method

[0001] Cross-reference to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202410913329.0, filed on July 9, 2024, entitled “System and Method for Detecting Holes in Strip”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to, but is not limited to, the field of battery technology, and in particular to a system and method for detecting voids in a material strip. Background Technology

[0004] New energy batteries are being used more and more widely in daily life and industry. For example, new energy vehicles equipped with batteries are already widely used. In addition, batteries are being used more and more in the field of energy storage.

[0005] Defects may exist during battery production, requiring various testing methods to detect them and improve battery yield. Before pinhole detection on the battery electrode substrate, the lack of routine inspection means that malfunctions in the detection system cannot be detected in time, easily leading to a large number of defective electrode substrates and resulting in substandard battery quality or reduced performance.

[0006] Summary of the Invention

[0007] In view of this, embodiments of the present disclosure provide a material strip hole detection system and method.

[0008] The technical solution disclosed herein is implemented as follows:

[0009] In a first aspect, embodiments of this disclosure provide a strip hole detection system for detecting hole size information, including a light source assembly, at least one camera, and an image processing unit, wherein: the light source assembly is disposed facing a first surface of the strip, irradiating the strip with light, and the irradiated area of ​​the light source assembly is greater than the maximum width of the strip; wherein the strip includes an electrode substrate; the light source assembly, during inspection, irradiates light onto an inspection piece carried on the strip; the maximum width of the inspection piece is less than or equal to the width of the strip; the inspection piece has holes of different sizes distributed on it, and the strip carrying the inspection piece includes at least the holes exposing the inspection piece. The notch; at least one camera, with its shooting direction facing the second surface of the strip; the shooting range of at least one camera is greater than the width of the strip; at least one camera is used to image the inspection piece under the illumination of the light source assembly; an image processing unit is used to detect the size information of the hole on the inspection piece based on the image to be inspected obtained by the imaging of the inspection piece, and to determine whether the inspection is successful; the camera is also used to image the strip under the illumination of the light source assembly if the inspection is successful; the image processing unit is also used to detect the size information of the hole on the strip based on the image to be inspected obtained by each camera.

[0010] In this embodiment, on the one hand, the illumination range of the light source component is greater than the maximum width of the strip and the maximum width of the inspection piece is less than or equal to the width of the strip, so that the edges of the strip or inspection piece and the holes on the inspection piece are illuminated, thereby enhancing the contrast between the holes on the strip or inspection piece and other strip areas or inspection piece areas other than the holes; on the other hand, the size information of the holes on the image to be detected obtained by the camera imaging of the strip by the image processing unit is detected, which is beneficial to timely detection of abnormal holes.

[0011] In some embodiments, the holes are pinholes, the light source assembly includes a linear light source; the inspection piece includes a plurality of pinholes arranged in an array with pinhole sizes ranging from large to small; wherein, the electrode substrate includes an anode copper foil and a cathode aluminum foil, and the electrode substrate is provided with notches corresponding to the pinholes on the inspection piece, so that light passes through the pinholes on the inspection piece and enters the camera.

[0012] In this embodiment, the electrode substrate is provided with a notch corresponding to the pinhole on the inspection piece, so that light passes through the pinhole on the inspection piece and enters the camera. As a result, the pinhole in the inspection piece image obtained by the camera appears white and the other areas of the inspection piece other than the pinhole appear black, thereby improving the contrast between the pinhole on the inspection piece and the other areas of the inspection piece other than the pinhole.

[0013] In some embodiments, the camera includes at least two cameras; the number of cameras is determined based on the maximum width of the electrode substrate, the minimum detection accuracy, and the resolution of the cameras; at least two cameras are equally spaced on the same support; at least two cameras are used to image the inspection sheet or the electrode substrate, respectively.

[0014] In this embodiment of the disclosure, by setting at least two cameras at equal intervals on the same bracket, the at least two cameras can quickly image the corresponding areas of the inspection sheet or electrode substrate, thereby ensuring that each camera can capture different areas of the inspection sheet or electrode substrate.

[0015] In some embodiments, the light source assembly includes a linear light source that illuminates an area greater than the width of the electrode substrate; and at least two cameras for imaging light rays leaking from both sides of the width of the electrode substrate.

[0016] In this embodiment of the present disclosure, at least two cameras are used to image the light leaking from both sides of the width of the electrode substrate to obtain a light image of the linear light source, which facilitates subsequent detection of the light brightness of the linear light source and reduces the time required to determine whether the linear light source is working properly.

[0017] In some embodiments, the detection system further includes an encoder, a light source controller, and an image acquisition controller; the encoder is used to simultaneously send trigger signals to the light source controller and the image acquisition controller; the light source controller is used to control the linear light source to turn on in response to the trigger signals; and the image acquisition controller is used to control at least two cameras to acquire images at a preset frequency in response to the trigger signals.

[0018] In this embodiment of the disclosure, by sending trigger signals to both the light source controller and the image acquisition controller simultaneously through the encoder, it can be ensured that both the light source controller and the image acquisition controller receive the trigger signals at the same time, thereby enabling the lighting of the light source component and the image acquisition of the camera to be performed simultaneously.

[0019] In some embodiments, at least two cameras include at least two line scan cameras; the at least two line scan cameras are used to acquire one line of image data of the corresponding area of ​​the electrode substrate within the field of view; the acquisition of one line of image data is performed cyclically, and the image data with a preset number of lines is output as the image to be detected of the electrode substrate to the image processing unit.

[0020] In this embodiment of the present disclosure, at least two line scan cameras are used to collect one row of image data of the corresponding area of ​​the electrode substrate within the field of view; the image data of one row is collected in a loop, and the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit, which can ensure that the image to be detected of the electrode substrate collected by at least two line scan cameras can completely cover the electrode substrate.

[0021] In some embodiments, the detection system further includes a programmable logic controller (PLC) and a marking machine; the image processing unit is further configured to perform pinhole detection on each image to be detected of the electrode substrate, obtain a corresponding pinhole detection result, and send the pinhole detection result to the PLC; the image processing unit is further configured to acquire a pulse identifier corresponding to a defective pinhole; generate a marking request based on the pulse identifier and send the marking request to the PLC; the PLC is configured to send a marking signal to the marking machine in response to the marking request; and the marking machine is configured to mark the defective pinhole in response to the marking signal.

[0022] In this embodiment of the present disclosure, the image processing unit generates and sends a marking request to the programmable logic controller based on the pulse identifier corresponding to the defective pinhole, which can improve the efficiency of the marking machine in marking defective pinholes, thereby realizing quality control and traceability of pinholes on the automated production line.

[0023] Secondly, this disclosure provides a method for detecting holes in a strip material, applied to a strip material hole detection system. The strip material hole detection system is used to detect the size information of the holes. The strip material hole detection system includes a light source assembly, at least one camera, and an image processing unit. The detection method includes: in response to a trigger signal, an image acquisition controller controls at least one camera to image a spot inspection piece illuminated by the light source assembly; wherein the light source assembly illuminates a first surface of the strip material or a spot inspection piece carried on the strip material, and the illuminated area of ​​the light source assembly is greater than the maximum width of the strip material; the maximum width of the spot inspection piece is less than or equal to the width of the strip material; the spot inspection piece has holes of different sizes distributed on it, and the strip material carrying the spot inspection piece includes at least a portion of the strip material with holes exposed. A notch; at least one camera, with its shooting direction facing the second surface of the strip; the shooting range of at least one camera is greater than the width of the strip; the strip includes an electrode substrate; the image acquisition controller outputs the inspection image of the inspection piece obtained by at least one camera to the image processing unit; the image processing unit, based on the inspection image of the inspection piece obtained by imaging, detects the size information of the hole on the inspection piece to determine whether the inspection is successful; if the inspection is successful, the image acquisition controller controls the camera to image the strip after the light source component illuminates it; the image acquisition controller outputs the inspection images of the strip obtained by each camera to the image processing unit; the image processing unit, based on the inspection images of each strip, detects the size information of the hole on the strip.

[0024] In this embodiment, on the one hand, the illumination range of the light source component is greater than the maximum width of the strip and the maximum width of the inspection piece is less than or equal to the width of the strip, so that the edges of the strip or inspection piece and the holes on the inspection piece are illuminated, thereby enhancing the contrast between the holes on the strip or inspection piece and other strip areas or inspection piece areas other than the holes; on the other hand, the size information of the holes on the image to be detected obtained by the camera imaging of the strip by the image processing unit is detected, which is beneficial to timely detection of abnormal holes.

[0025] In some embodiments, the strip hole detection system further includes an encoder and a light source controller; the light source assembly includes a linear light source, and at least one camera includes at least two line scan cameras. The method further includes: the encoder simultaneously sending a trigger signal to the light source controller and the image acquisition controller; the light source controller, in response to the trigger signal, controlling the linear light source to turn on; the image acquisition controller, in response to the trigger signal, controlling at least two line scan cameras to acquire images at a preset frequency; the at least two line scan cameras respectively acquire one row of image data of the corresponding area of ​​the electrode substrate within the field of view; the above acquisition steps are repeated, and the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit.

[0026] In this embodiment, on the one hand, by simultaneously sending trigger signals to the light source controller and the image acquisition controller via the encoder, it can be ensured that the light source controller and the image acquisition controller receive the trigger signals at the same time, thereby enabling the lighting of the light source component and the image acquisition by the camera to be performed simultaneously. On the other hand, by acquiring one row of image data of the corresponding area of ​​the electrode substrate within the field of view by at least two line scan cameras respectively; by repeating the above acquisition steps, the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit, which can ensure that the image to be detected of the electrode substrate acquired by at least two line scan cameras can completely cover the electrode substrate.

[0027] In some embodiments, the holes are pinholes, and the method further includes: an image processing unit determining an inspection area based on the image to be inspected of the inspection area; determining the pinholes and the number of pinholes in the inspection area based on the gray values ​​corresponding to each pixel in the inspection area; determining the size of each pinhole based on each pixel in each pinhole; and determining that the inspection is successful when the difference between the size of each pinhole and the size of a preset pinhole is within a first preset range and the number of pinholes is equal to the actual number of pinholes in the inspection area.

[0028] In this embodiment, on the one hand, the image processing unit determines the inspection area based on the image to be inspected of the inspection patch, and further determines the pinholes and the number of pinholes in the inspection patch area based on the grayscale value corresponding to each pixel in the inspection patch area. This can accurately identify the pinholes and the number of pinholes, thereby reducing the possibility of misjudgment and omission of the number of pinholes. On the other hand, the image processing unit determines the size of each pinhole based on each pixel in each pinhole, and compares the difference between the size of each pinhole and the preset pinhole size with a first preset range. This helps to determine whether the inspection is successful, thereby ensuring that the quality of the image to be inspected of the electrode substrate subsequently captured by the camera meets the requirements.

[0029] In some embodiments, the image processing unit determines the inspection area based on the inspection area's image to be inspected, including: performing grayscale processing on the inspection area's image to be inspected to obtain a grayscale image of the inspection area; determining the grayscale difference between two adjacent pixels based on the grayscale values ​​corresponding to each pixel in the grayscale image; determining the pixel corresponding to the grayscale difference between two adjacent pixels that is greater than a preset grayscale threshold as a target pixel; and fitting the target pixel to obtain the inspection area.

[0030] In this embodiment of the present disclosure, on the one hand, the image processing unit determines the grayscale difference between two adjacent pixels based on the grayscale value of each pixel in the grayscale image of the inspection piece, which helps to improve the accuracy of subsequently determining the inspection piece area; on the other hand, by setting a grayscale threshold, pixels with a grayscale difference greater than the threshold can be selected as target pixels, which can effectively filter out the electrode substrate area, thereby improving the accuracy of the inspection piece area.

[0031] In some embodiments, the method further includes: acquiring light images of a linear light source captured by at least two cameras; the light images are obtained after the at least two cameras image the light rays generated by the linear light source on both sides of the width of the exposed electrode substrate, the electrode substrate including an anode copper foil and a cathode aluminum foil; determining that the linear light source is working normally when the grayscale value of each pixel in the light image is within a second preset range; wherein the number of cameras is determined based on the maximum width of the electrode substrate, the minimum detection accuracy, and the resolution of the cameras.

[0032] In this embodiment of the disclosure, by using an image processing unit to detect the light image of the linear light source based on the light image captured by the camera, problems can be detected before the performance of the linear light source deteriorates or fails, thereby enabling timely maintenance or replacement of the linear light source.

[0033] In some embodiments, the image processing unit performs pinhole detection on the image to be detected of the electrode substrate to obtain a pinhole detection result, including: preprocessing each image to be detected to obtain a preprocessed image to be detected; performing edge detection on each preprocessed image to be detected of the electrode substrate to obtain an electrode substrate region of each image to be detected; stitching together each electrode substrate region to obtain an electrode substrate image; and performing pinhole detection on the electrode substrate image to obtain a pinhole detection result.

[0034] In this embodiment of the disclosure, on the one hand, edge detection is performed on each pre-processed image to be detected of the electrode substrate by the image processing unit, which can accurately distinguish the electrode substrate area and the background area; on the other hand, pinhole detection is performed on the complete image of the electrode substrate, which can ensure that all pinholes on the electrode substrate are detected.

[0035] In some embodiments, pinhole detection is performed on the electrode substrate image to obtain pinhole detection results, including: determining the pinholes in the electrode substrate image and the size of each pinhole based on the grayscale value corresponding to each pixel in the electrode substrate image; and determining that the pinhole is unqualified if the difference between the size of each pinhole and a preset value is not within a third preset range.

[0036] In this embodiment of the present disclosure, the image processing unit detects whether each pinhole in the electrode substrate is qualified, and takes necessary measures in a timely manner to deal with unqualified pinholes, which helps to reduce the scrap rate and improve the quality of the electrode substrate.

[0037] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of this disclosure. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0039] Figure 1 is a schematic diagram of the overall hardware layout of a strip hole detection system provided in an embodiment of this disclosure;

[0040] Figure 2 is a schematic diagram of the composition structure of a material strip hole detection system provided in an embodiment of this disclosure;

[0041] Figure 3 is a schematic diagram of an inspection piece provided in an embodiment of this disclosure;

[0042] Figure 4 is a schematic diagram of the layout of various components in the detection station of a strip hole detection system provided in an embodiment of this disclosure;

[0043] Figure 5 is a schematic diagram of the implementation process of a material strip hole detection method provided in an embodiment of this disclosure;

[0044] Figure 6 is a schematic image of an electrode substrate provided in an embodiment of this disclosure;

[0045] Figure 7 is a schematic diagram of the implementation process of an inspection method provided in an embodiment of this disclosure;

[0046] Figure 8 is a schematic diagram of the implementation process of a pinhole detection method for aluminum foil provided in an embodiment of this disclosure. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the specific technical solutions of this disclosure will be further described in detail below with reference to the accompanying drawings of the embodiments of this disclosure. The following embodiments are used to illustrate this disclosure, but are not intended to limit the scope of this disclosure.

[0048] Unless otherwise defined, all technical and scientific terms used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in this disclosure is for the purpose of describing embodiments of this disclosure only and is not intended to be limiting of this disclosure.

[0049] In the following description, references to "some embodiments," "this embodiment," "this disclosure embodiment," and examples, etc., describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0050] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0051] Lithium-ion batteries use copper foil as the anode substrate and aluminum foil as the cathode substrate. During multiple production processes, various factors such as extrusion and transportation can cause unevenness, scratches, and wrinkles on the electrode substrate surface, leading to perforation quality problems. These perforations and light transmission defects in the electrode substrate affect the quality of the lithium-ion battery. Currently, there are two methods for detecting defects in the electrode substrate: Method 1: Manual inspection of the electrode substrate. However, manual inspection cannot effectively detect tiny pinholes on the electrode substrate, resulting in low inspection efficiency and failing to meet the inspection requirements of automated manufacturing. Method 2: Using photoelectric sensors and a Camlink interface line scan camera to inspect the electrode substrate. However, photoelectric sensor detection cannot save intuitive images for backtesting. For Camlink interface line scan cameras, the maximum resolution is 16384. Even if the line scan camera's field of view and accuracy meet the requirements, the high operating speed of the equipment, limited by the Camlink data cable's transmission speed, can cause some longitudinal sections of the electrode substrate to be lost due to insufficient acquisition time, resulting in incomplete images of the electrode substrate output by the line scan camera. In addition, when the width of the electrode substrate is large, the field of view of the line scan camera on the electrode substrate must also be increased accordingly, which makes it impossible to meet the accuracy requirements.

[0052] Based on this, the present disclosure provides a strip hole detection system and method. On the one hand, the illumination range of the light source component is greater than the maximum width of the strip and the maximum width of the inspection piece is less than or equal to the width of the strip, so that the edges of the strip or inspection piece and the holes on the inspection piece are illuminated, thereby enhancing the contrast between the holes on the strip or inspection piece and other strip areas or inspection piece areas other than the holes. On the other hand, the size information of the holes on the image of the strip to be detected obtained by the camera is detected by the image processing unit, which is beneficial to timely detection of abnormal holes.

[0053] This disclosure provides an overall hardware layout for a strip hole detection system, as shown in Figure 1. The overall hardware includes a linear light source 11, a line scan camera 12, an industrial computer 13, a central control display 14, a programmable logic controller 15, an encoder 16, a marking machine 17, and a pressing wheel 19. The linear light source 11 can be a white linear light source, used to vertically illuminate the back of the electrode substrate, thus illuminating the pinholes on the electrode substrate. The size of the linear light source can be selected according to requirements; selecting a light source with high brightness and excellent uniformity can effectively ensure image consistency. The line scan camera 12 can be a CoaXPress interface line scan camera. Compared to a Camlink interface camera, the CoaXPress interface line scan camera has a faster image capture speed and is used to perform line-by-line exposure according to the running speed and rhythm of the electrode substrate 18, forming a complete line scan image that meets the size requirements. The industrial computer 13 serves as the image processing terminal in the system, containing a core computing model 131, which can adapt to various operating systems and meet the requirements of various development languages ​​for host computer software operation. The central control display 14 is used to organize and summarize the processing results output by the industrial computer 13, arrange and display them after graphical operation, link various integrated functions, and interact with the user on the front-end interface. The programmable logic controller (PLC) 15 can interact with the industrial computer 13, for example, loading the industrial computer's control instructions into memory for storage and execution at any time. The industrial computer is mainly responsible for distance calculation. After receiving an alarm signal from the industrial computer, the marking machine marks the unqualified pinholes after controlling a certain distance. The encoder 16 is generally pressed onto the unwinding roller. During the movement of the electrode substrate 18, it drives the pressing wheel 19 to rotate together. The encoder outputs a pulse signal every time it rotates a certain angle, triggering the line scan camera to capture a line of image data of the electrode substrate, thereby driving the uniformity of the line scan camera's shooting frequency and the movement speed of the electrode substrate, ensuring that the line scan camera stably outputs line scan images at different speeds. The marking machine 17 can be driven by a motor to affix self-adhesive to the defective position of the electrode substrate 18 to mark the defect and remind subsequent processes to avoid and handle it.

[0054] This disclosure provides a material hole detection system for detecting hole size information. As shown in FIG2, the strip hole detection system 200 includes a light source assembly 210, at least one camera 220, and an image processing unit 230.

[0055] The light source assembly 210 is disposed on a first surface facing the material strip, and illuminates the material strip with light, and the area illuminated by the light source assembly is greater than the maximum width of the material strip; wherein, the material strip includes an electrode substrate;

[0056] During inspection, the light source assembly 210 illuminates the inspection piece carried on the material strip with light; the maximum width of the inspection piece is less than or equal to the width of the material strip; the inspection piece has holes of different sizes distributed on it, and the material strip carrying the inspection piece includes a notch that exposes at least the holes of the inspection piece.

[0057] Here, the light source component can be a strip light source, an array light source, etc. Taking a light-emitting diode (LED) lamp as an example, in some embodiments, a strip light source can be composed of multiple LEDs arranged in a straight line; an array light source can include multiple strip light sources connected end to end to form a square frame structure. Both strip light sources and array light sources can produce high-intensity light and uniform illumination, resulting in clear and bright lighting effects for the inspection sheet. This uniform illumination helps reduce shadows and reflections, thereby improving image quality. It should be noted that the light source component in the embodiments of this disclosure can be any of the above-mentioned light sources.

[0058] In some implementations, the light source assembly can be controlled to turn on and off in two ways. Method 1: Controlling the light source assembly through a separate light source controller. For example, the light source controller can receive external control signals to determine the parameters that need adjustment, then convert these parameters into corresponding voltage or current values, and finally control the illumination state of the light source assembly (e.g., on / off) through an output circuit. Method 2: Controlling the light source assembly by combining an encoder with the light source controller. The encoder can convert angular or linear displacement into electrical signals, which can be input into the light source controller to control the illumination state of the light source assembly.

[0059] Here, the inspection film can be a film, and the film can be an opaque black substrate. As shown in Figure 3, the film 30 has holes of different sizes distributed on it. For example, the diameter of the holes can be 2 mm, 1.6 mm, 1.2 mm, etc., from largest to smallest.

[0060] Here, the inspection pads carried on the conveyor belt refer to pads that are attached to the surface of the conveyor belt and move with the belt as its moving carrier. In other words, the inspection pads move accordingly as the conveyor belt moves. For example, if the conveyor belt is placed on a conveyor roller, the belt will move as the roller rotates, and thus, the inspection pads will also move with the belt. It should be noted that the conveyor belt's moving speed can be 200 meters per minute (m / min).

[0061] Here, the first surface can be either the upper surface or the lower surface. If the first surface is the upper surface, then the second surface is the lower surface opposite to the upper surface; if the first surface is the lower surface, then the second surface is the upper surface opposite to the lower surface. The following explanation will use the example of the first surface being the upper surface and the second surface being the lower surface.

[0062] In some implementations, the light source assembly illuminates the upper surface of the strip, or illuminates the inspection piece carried on the strip. Furthermore, the illumination range of the light source assembly is greater than the maximum width of the strip, and the maximum width of the inspection piece is less than or equal to the width of the strip, such that the illumination range of the light source assembly completely covers the inspection piece or the strip.

[0063] Here, the material strip carrying the inspection piece, including at least the notch exposing the holes of the inspection piece, can mean that the holes on the inspection piece are not covered by the material strip. In some embodiments, the holes on the inspection piece can be kept uncovered by the material strip in two ways: Method 1, cut an area of ​​the same size as the inspection piece from the material strip to obtain a cutout area on the material strip, and attach the inspection piece to the cutout area; Method 2, first attach the inspection piece to the material strip, and then cut off the material strip area corresponding to the holes on the inspection piece in a horizontal or vertical strip shape.

[0064] The at least one camera 220 is positioned to capture images of the second surface of the material strip; the shooting range of the at least one camera is greater than the width of the material strip.

[0065] Here, at least one camera can be one camera, two cameras, three cameras, four cameras, etc. The following explanation uses four cameras as an example. In some implementations, the four cameras are positioned to capture images of the lower surface of the conveyor belt, and the shooting range of the four cameras is greater than the width of the conveyor belt, allowing the four cameras to capture a complete image of the inspection sheet or a complete image of the conveyor belt.

[0066] The at least one camera 220 is used to image the inspection piece under the illumination of the light source assembly;

[0067] In some implementations, four cameras image the inspection piece under the illumination of a light source assembly to obtain the inspection image of the inspection piece.

[0068] In some implementations, a portion of the light emitted by the light source assembly is reflected by the upper surface of the inspection piece and does not enter the camera, causing the inspection piece to appear black in the inspection image captured by the camera; the other portion of the light passes through the holes on the inspection piece, causing the holes to appear white in the inspection image captured by the camera, thereby enhancing the contrast between the holes on the inspection piece and other areas of the inspection piece, making it easier for the camera to capture the holes on the inspection piece.

[0069] The image processing unit 230 is used to detect the size information of the holes on the inspection piece based on the image to be inspected obtained by imaging, and to determine whether the inspection is successful.

[0070] Here, the image processing unit can be a vision host computer. A vision host computer is an important component of a machine vision system. It is usually a computer or a dedicated device (e.g., an industrial control computer) used to control and manage the entire machine vision system. It can receive images from image acquisition devices (e.g., cameras) and perform image processing and analysis on them.

[0071] Here, a successful inspection indicates that all components in the strip hole detection system (e.g., light source assembly, at least one camera, image processing unit, etc.) are installed in place and in normal condition; an unsuccessful inspection indicates that some components in the strip hole detection system are not installed in place or are in an abnormal state.

[0072] In some implementations, the image processing unit detects the image of the inspection piece obtained by the camera to determine whether the inspection was successful.

[0073] The camera is also used to image the strip under the illumination of the light source assembly if the inspection is successful.

[0074] In some implementations, four cameras image the lower surface of the strip under the illumination of the light source assembly to obtain an image of the strip to be inspected.

[0075] In some implementations, a portion of the light emitted by the light source assembly is reflected by the upper surface of the strip and does not enter the camera, causing the strip to appear black in the image of the strip to be inspected captured by the camera; the other portion of the light passes through the holes in the strip, causing the holes to appear white in the image of the strip to be inspected captured by the camera, thereby enhancing the contrast between the holes in the strip and other areas of the strip, making it easier for the camera to capture the holes in the strip.

[0076] It should be noted that the camera used in this embodiment has a high resolution, which can capture more details of the holes on the material strip or inspection sheet, thus helping to improve the accuracy of subsequent inspection of the holes on the material strip or inspection sheet.

[0077] The image processing unit is further configured to detect the size information of the holes on the material strip based on the images of the material strip to be detected obtained by each of the cameras.

[0078] In some implementations, an image processing unit detects the size information of holes on the material strip based on the image of the material strip obtained by the camera, and obtains the hole detection result.

[0079] In this embodiment, on the one hand, the illumination range of the light source component is greater than the maximum width of the strip and the maximum width of the inspection piece is less than or equal to the width of the strip, so that the edges of the strip or inspection piece and the holes on the inspection piece are illuminated, thereby enhancing the contrast between the holes on the strip or inspection piece and other strip areas or inspection piece areas other than the holes; on the other hand, the size information of the holes on the image to be detected obtained by the camera imaging of the strip by the image processing unit is detected, which is beneficial to timely detection of abnormal holes.

[0080] In some embodiments, the hole is a pinhole, the light source assembly includes a linear light source; the inspection piece includes a plurality of pinholes arranged in an array with pinhole sizes ranging from large to small; wherein, the electrode substrate includes an anode copper foil and a cathode aluminum foil, and the electrode substrate is provided with notches corresponding to the pinholes on the inspection piece, so that light passes through the pinholes on the inspection piece and enters the camera.

[0081] Here, a linear light source can be a specially designed cylindrical lens focusing ultra-high brightness LED. Its shape is typically elongated, providing uniform and consistent high-intensity linear illumination to the electrode substrate and inspection piece. This helps reduce shadows caused by unevenness or tilting of the electrode substrate or inspection piece surface. In pinhole detection of the electrode substrate or inspection piece, shadows can obscure or mislead the detection of pinholes. By using a linear light source, the interference of shadows can be significantly reduced, improving the reliability of pinhole detection.

[0082] Here, as shown in Figure 3, the inspection piece 30 includes multiple pinholes arranged in an array with pinhole sizes ranging from large to small. It should be noted that Figure 3 only shows a portion of the pinholes on the inspection piece.

[0083] Here, since the battery substrate includes an anode copper foil and a cathode aluminum foil, the electrode substrate for pinhole detection in this embodiment of the disclosure can be an anode copper foil and / or a cathode aluminum foil.

[0084] In this embodiment, the electrode substrate is provided with a notch corresponding to the pinhole on the inspection piece, so that light passes through the pinhole on the inspection piece and enters the camera. As a result, the pinhole in the inspection piece image obtained by the camera appears white and the other areas of the inspection piece other than the pinhole appear black, thereby improving the contrast between the pinhole on the inspection piece and the other areas of the inspection piece other than the pinhole.

[0085] In some embodiments, the camera includes at least two cameras; the number of cameras is determined based on the maximum width of the electrode substrate, the minimum detection accuracy, and the resolution of the camera; at least two cameras are equally spaced on the same support; the at least two cameras are used to image the inspection piece or the electrode substrate, respectively.

[0086] Here, "at least two" can refer to two, three, four, etc., and the number of cameras is related to the maximum width of the electrode substrate, the minimum detection accuracy, and the camera resolution. In some embodiments, the number of cameras is determined based on the maximum width of the electrode substrate, the minimum detection accuracy, and the camera resolution. This may include: determining the number of pixels to be detected per unit length based on the maximum width of the electrode substrate and the required minimum detection accuracy; and determining how many such cameras are needed to cover the maximum width of the electrode substrate and achieve the required minimum detection accuracy based on the camera resolution.

[0087] Next, we will take four cameras as an example to introduce the layout of each component in the detection station of the strip hole detection system. As shown in Figure 4, the detection station is equipped with four cameras, namely the first camera 401, the second camera 402, the third camera 403 and the fourth camera 404. The first camera 401 to the fourth camera 404 and the linear light source 43 are respectively set on two opposite surfaces (e.g., the upper surface and the lower surface) of the electrode substrate 42, and the first camera 401 to the fourth camera 404 are equally spaced on the same bracket 41.

[0088] Here, the equal interval can be a suitable value determined based on the maximum width of the electrode substrate, the number of cameras, and the field of view of each camera. The equal interval can be 8 cm, 9 cm, 10 cm, etc.

[0089] In some embodiments, at least two cameras are used to take images of corresponding areas of the inspection piece to obtain an image to be inspected of the inspection piece area; at least two cameras are used to take images of corresponding areas of the battery substrate to obtain an image to be inspected of the battery substrate area.

[0090] In this embodiment of the disclosure, by setting at least two cameras at equal intervals on the same bracket, the at least two cameras can quickly image the corresponding areas of the inspection sheet or electrode substrate, thereby ensuring that each camera can capture different areas of the inspection sheet or electrode substrate.

[0091] In some embodiments, the light source assembly includes a linear light source that illuminates an area greater than the width of the electrode substrate; the at least two cameras are also used to image light rays leaking from both sides of the width of the electrode substrate.

[0092] Here, if a linear light source illuminates the upper surface of the electrode substrate, a portion of the light emitted by the linear light source is reflected by the upper surface of the electrode substrate and does not enter the camera, causing the electrode substrate to appear black in the image of the electrode substrate to be inspected captured by the camera; another portion of the light passes through the pinhole on the electrode substrate, causing the pinhole to appear white in the image of the electrode substrate to be inspected captured by the camera; and a portion of the light leaks out from both sides of the width of the electrode substrate, allowing the camera to capture an image of the linear light source. As shown in Figure 4, the image of the linear light source captured by the first camera 401 may include a first light region 441; the image of the linear light source captured by the fourth camera 404 may include a second light region 442.

[0093] In this embodiment of the present disclosure, at least two cameras are used to image the light leaking from both sides of the width of the electrode substrate to obtain a light image of the linear light source, which facilitates subsequent detection of the light brightness of the linear light source and reduces the time required to determine whether the linear light source is working properly.

[0094] In some embodiments, the detection system further includes an encoder, a light source controller, and an image acquisition controller; the encoder is configured to simultaneously send trigger signals to the light source controller and the image acquisition controller.

[0095] Here, by simultaneously sending trigger signals to both the light source controller and the image acquisition controller via the encoder, synchronous operation between the two can be achieved. The image acquisition controller can be an image acquisition card. In some embodiments, the image to be detected obtained by the camera can be stored in the image acquisition card first, and then the image acquisition card will send the image to be detected to the image processing unit for analysis and processing.

[0096] The light source controller is used to control the linear light source to turn on in response to the trigger signal;

[0097] Here, the operation of the linear light source is controlled by combining an encoder and a light source controller. The encoder can convert angular or linear displacement into electrical signals, which can be input into the light source controller to control the activation of the linear light source.

[0098] The image acquisition controller is used to control the at least two cameras to acquire images at a preset frequency in response to the trigger signal.

[0099] Here, the preset frequency can be a pre-set appropriate value. While the light source controller controls the linear light source to turn on, the image acquisition controller controls at least two cameras to acquire images at the preset frequency.

[0100] In this embodiment of the disclosure, by sending trigger signals to both the light source controller and the image acquisition controller simultaneously through the encoder, it can be ensured that both the light source controller and the image acquisition controller receive the trigger signals at the same time, thereby enabling the lighting of the light source component and the image acquisition of the camera to be performed simultaneously.

[0101] In some embodiments, the at least two cameras include at least two line scan cameras; the at least two line scan cameras are used to acquire one row of image data corresponding to the electrode substrate within the field of view; the acquisition of the row of image data is performed cyclically, and the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit.

[0102] Here, the line scan camera works differently from ordinary area scan cameras. It scans the moving electrode substrate line by line, acquiring only one line of image data at a time. These image data are stitched together to form a complete image of the electrode substrate to be inspected.

[0103] Here, the preset number of rows can be a suitable value set in advance based on the length of the electrode substrate. For example, the preset number of rows can be 1000 rows, 1100 rows, 1200 rows, etc. The following explanation will take four line scan cameras and a preset number of 1200 rows as an example.

[0104] In some implementations, four line scan cameras each acquire a line of image data corresponding to the area of ​​the electrode substrate within their field of view; the acquisition of one line of image data is performed cyclically, and the 1200 lines of image data corresponding to the area of ​​the electrode substrate are output as the image to be detected of the electrode substrate to the image processing unit.

[0105] It should be noted that the four line scan cameras are set at equal intervals on the same bracket. Each line scan camera captures a region of the electrode substrate, and there is an overlap in the field of view of the electrode substrate between adjacent line scan cameras. In this way, a part of the electrode substrate will be captured by two line scan cameras. The field of view of the electrode substrate captured by the four line scan cameras is greater than the maximum width of the electrode substrate. Thus, the image of the electrode substrate to be inspected captured by the four line scan cameras can completely cover the electrode substrate.

[0106] In this embodiment of the present disclosure, at least two line scan cameras are used to collect one row of image data of the corresponding area of ​​the electrode substrate within the field of view; the image data of one row is collected in a loop, and the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit, which can ensure that the image to be detected of the electrode substrate collected by at least two line scan cameras can completely cover the electrode substrate.

[0107] In some embodiments, the detection system further includes a programmable logic controller and a marking machine; the image processing unit is further configured to perform pinhole detection on each of the images to be detected on the electrode substrate, obtain a corresponding pinhole detection result, and send the pinhole detection result to the programmable logic controller;

[0108] Here, the pinhole detection result can be either "pass" or "fail". Regardless of whether the image processing unit detects a pass or fail, it will send the pinhole detection result to the programmable logic controller (PLC). For example, if the image processing unit detects a pass, it sends a pass result to the PLC; if it detects a fail, it sends a fail result to the PLC.

[0109] In some implementations, the image processing unit performs pinhole detection on the image of the electrode substrate and sends the pinhole detection results to the programmable logic controller (PLC) for subsequent processing and response.

[0110] Here, the programmable logic controller (PLC) is used to receive the pinhole detection results sent by the vision host computer and may perform corresponding operations based on these results. For example, if the size of the pinhole exceeds a preset threshold, the PLC may send a signal to stop the movement of the electrode substrate and trigger an alarm.

[0111] The image processing unit is further configured to acquire the pulse identifier corresponding to the defective pinhole; generate a marking request based on the pulse identifier, and send the marking request to the programmable logic controller;

[0112] Here, the pulse identifier can be the location of the pulse signal corresponding to the defective pinhole.

[0113] The programmable logic controller is configured to send a marking signal to the marking machine in response to the marking request; the marking machine is configured to mark the defective pinholes in response to the marking signal.

[0114] In this embodiment of the present disclosure, the image processing unit generates and sends a marking request to the programmable logic controller based on the pulse identifier corresponding to the defective pinhole, which can improve the efficiency of the marking machine in marking defective pinholes, thereby realizing quality control and traceability of pinholes on the automated production line.

[0115] This disclosure provides a method for detecting holes in a strip material, applied to a strip material hole detection system. The strip material hole detection system is used to detect the size information of the holes. The strip material hole detection system includes a light source assembly, at least one camera, and an image processing unit. As shown in FIG5, the strip material hole detection method may include the following steps S510 and S560, wherein:

[0116] In step S510, in response to the trigger signal, the image acquisition controller controls at least one camera to image the inspection piece after the light source component has illuminated it;

[0117] Here, the light source assembly illuminates light onto the first surface of the strip or onto the inspection piece carried on the strip, and the area illuminated by the light source assembly is greater than the maximum width of the strip; the maximum width of the inspection piece is less than or equal to the width of the strip; the inspection piece has holes of different sizes distributed on it, and the strip carrying the inspection piece includes a notch that exposes at least the holes of the inspection piece; the at least one camera is positioned with its shooting direction facing the second surface of the strip; the shooting range of the at least one camera is greater than the width of the strip; the strip includes an electrode substrate.

[0118] Here, the trigger signal can be a pulse signal emitted by the encoder. In some implementations, firstly, when the inspection piece arrives at the inspection station, the encoder sends a pulse signal to the image acquisition controller; then, after receiving the pulse signal, the image acquisition controller, in response to the pulse signal, controls at least one camera to image the inspection piece after it has been illuminated by the light source assembly, thereby obtaining the image of the inspection piece to be inspected.

[0119] In some implementations, a portion of the light emitted by the light source assembly is reflected by the upper surface of the inspection piece and does not enter the camera, causing the inspection piece to appear black in the inspection image captured by the camera; the other portion of the light passes through the holes on the inspection piece, causing the holes to appear white in the inspection image captured by the camera, thereby enhancing the contrast between the holes on the inspection piece and other areas of the inspection piece, making it easier for the camera to capture the holes on the inspection piece.

[0120] Step S520: The image acquisition controller outputs the image to be detected of the inspection piece obtained by the at least one camera to the image processing unit.

[0121] In some implementations, the image acquisition controller outputs the image to be inspected of the inspection piece obtained by at least one camera to the image processing unit, so that the image processing unit can detect the size information of the holes on the inspection piece in the image to be inspected.

[0122] Step S530: The image processing unit detects the size information of the holes on the inspection piece based on the image to be inspected obtained by imaging, and determines whether the inspection is successful.

[0123] Step S540: If the inspection is successful, the image acquisition controller controls the camera to image the strip after the light source assembly illuminates it.

[0124] In some implementations, firstly, when the material strip arrives at the inspection station, the encoder sends a pulse signal to the image acquisition controller; then, after receiving the pulse signal, the image acquisition controller, in response to the pulse signal, controls at least one camera to image the material strip after it has been illuminated by the light source assembly, thereby obtaining the image of the material strip to be inspected.

[0125] In some implementations, a portion of the light emitted by the light source assembly is reflected by the upper surface of the strip and does not enter the camera, causing the strip to appear black in the image to be inspected captured by the camera; the other portion of the light passes through the holes in the strip, causing the holes to appear white in the image to be inspected captured by the camera, thereby enhancing the contrast between the holes in the strip and other areas of the strip, making it easier for the camera to capture the holes in the strip.

[0126] In step S550, the image acquisition controller outputs the images of the material strip to be detected obtained by each of the cameras to the image processing unit.

[0127] In some implementations, the image acquisition controller outputs an image of the material strip to be inspected, obtained by at least one camera, to an image processing unit, so that the image processing unit can detect the size information of the holes in the image of the material strip to be inspected.

[0128] In step S560, the image processing unit detects the size information of the holes on the material strips based on the images to be detected of each material strip.

[0129] In this embodiment, on the one hand, the illumination range of the light source component is greater than the maximum width of the strip and the maximum width of the inspection piece is less than or equal to the width of the strip, so that the edges of the strip or inspection piece and the holes on the inspection piece are illuminated, thereby enhancing the contrast between the holes on the strip or inspection piece and other strip areas or inspection piece areas other than the holes; on the other hand, the size information of the holes on the image to be detected obtained by the camera imaging of the strip by the image processing unit is detected, which is beneficial to timely detection of abnormal holes.

[0130] In some embodiments, the strip hole detection system further includes an encoder and a light source controller; the light source assembly includes a linear light source, the at least one camera includes at least two line scan cameras, and the method further includes the following steps S521 to S524, wherein:

[0131] Step S521: The encoder simultaneously sends trigger signals to the light source controller and the image acquisition controller;

[0132] In step S522, the light source controller, in response to the trigger signal, controls the linear light source to turn on;

[0133] Step S523, the image acquisition controller, in response to the trigger signal, controls the at least two line scan cameras to acquire images at a preset frequency;

[0134] Here, while the light source controller turns on the linear light source, the image acquisition controller controls at least two cameras to acquire images at a preset frequency.

[0135] Step S524: The at least two line scan cameras respectively acquire one row of image data of the corresponding area of ​​the electrode substrate within the field of view; repeat the above acquisition steps, and output the image data with a preset number of rows as the image to be detected of the electrode substrate to the image processing unit.

[0136] In some implementations, at least two line scan cameras respectively acquire one row of image data of the corresponding area of ​​the electrode substrate within the field of view; the above acquisition steps are repeated, and the image data of a preset number of rows of the corresponding area of ​​the electrode substrate is output as the image to be detected of the electrode substrate to the image processing unit.

[0137] In this embodiment, on the one hand, by simultaneously sending trigger signals to the light source controller and the image acquisition controller via the encoder, it can be ensured that the light source controller and the image acquisition controller receive the trigger signals at the same time, thereby enabling the lighting of the light source component and the image acquisition by the camera to be performed simultaneously. On the other hand, by acquiring one row of image data of the corresponding area of ​​the electrode substrate within the field of view by at least two line scan cameras respectively; by repeating the above acquisition steps, the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit, which can ensure that the image to be detected of the electrode substrate acquired by at least two line scan cameras can completely cover the electrode substrate.

[0138] In some embodiments, the hole is a pinhole, and the method may further include the following steps S531 to S534, wherein:

[0139] Step S531: The image processing unit determines the inspection area based on the image to be detected of the inspection piece;

[0140] Here, since the image to be inspected includes not only the complete inspection area but also a portion of the electrode substrate connected to the edge of the inspection piece, it is necessary to determine the inspection area from the image to be inspected of the inspection piece.

[0141] In some implementations, the image processing unit determines the inspection area based on the difference between the gray values ​​of the pixels in the inspection area and the gray values ​​of the pixels in the electrode substrate area.

[0142] Step S532: Based on the grayscale value corresponding to each pixel in the inspection area, determine the pinholes and the number of pinholes in the inspection area.

[0143] Here, the grayscale value of the pixel corresponding to the pinhole in the inspection area is different from the grayscale value of other pixels. Since the pinhole is white and other areas are black, the grayscale value of the pixel corresponding to the pinhole is greater than the grayscale value of the pixels in other areas. Therefore, the image processing unit can determine the pinhole from the inspection area based on the grayscale value of each pixel. After determining all the pinholes in the inspection area, the number of pinholes in the inspection area can be determined by counting the pinholes in the inspection area.

[0144] Step S533: Determine the size of each pinhole based on each pixel in each pinhole;

[0145] Here, the smallest pinhole size corresponds to one pixel. Therefore, we can first determine the number of pixels in each pinhole, and then determine the size of the corresponding pinhole based on the number of pixels in each pinhole.

[0146] Step S534: If the difference between the size of each pinhole and the preset pinhole size is within a first preset range and the number of pinholes is equal to the actual number of pinholes on the inspection piece, then the inspection is determined to be successful.

[0147] Here, the preset pinhole size can be one pixel, and the first preset range can be a suitable range set according to the preset pinhole size, for example, 0 to 0.5 mm.

[0148] Here, a successful inspection indicates that the strip hole detection system is in normal working order, while an unsuccessful inspection indicates that the system is in an abnormal state. An abnormal state may be caused by the following two situations: Situation 1: The brightness of the light emitted by the light source component is attenuated, which may cause larger pinholes on the inspection piece to be illuminated while smaller pinholes are not, resulting in the camera capturing an image of the inspection piece that does not completely cover all pinholes on the inspection piece; Situation 2: The camera's accuracy does not meet the detection requirements, which may also cause the camera capturing an image of the inspection piece that does not completely cover all pinholes on the inspection piece.

[0149] In some implementations, the inspection is considered successful when the number of pinholes in the image to be inspected of the inspection piece is equal to the actual number of pinholes in the inspection piece, and the difference between the size of each pinhole in the image to be inspected of the inspection piece and the size of a preset pinhole is within a first preset range.

[0150] In some embodiments, the image processing unit may first determine whether the number of pinholes in the inspection area is equal to the actual number of pinholes in the inspection area. If the number of pinholes in the inspection area is not equal to the actual number of pinholes in the inspection area, the inspection is determined to be unsuccessful. If the number of pinholes in the inspection area is equal to the actual number of pinholes in the inspection area, the unit may then determine whether the difference between the size of each pinhole in the inspection area and the size of a preset pinhole is within a first preset range. If the difference between the size of each pinhole and the size of the preset pinhole is not within the first preset range, the inspection is determined to be unsuccessful. If the difference between the size of each pinhole in the inspection area and the size of the preset pinhole is within the first preset range, the inspection is determined to be successful.

[0151] In this embodiment, on the one hand, the image processing unit determines the inspection area based on the image to be inspected of the inspection patch, and further determines the pinholes and the number of pinholes in the inspection patch area based on the grayscale value corresponding to each pixel in the inspection patch area. This can accurately identify the pinholes and the number of pinholes, thereby reducing the possibility of misjudgment and omission of the number of pinholes. On the other hand, the image processing unit determines the size of each pinhole based on each pixel in each pinhole, and compares the difference between the size of each pinhole and the preset pinhole size with a first preset range. This helps to determine whether the inspection is successful, thereby ensuring that the quality of the image to be inspected of the electrode substrate subsequently captured by the camera meets the requirements.

[0152] In some embodiments, the implementation of step S531, "the image processing unit determines the inspection patch region based on the image to be detected of the inspection patch," may include the following steps S5311 to S5314, wherein:

[0153] Step S5311: Perform grayscale processing on the image to be inspected of the inspection piece to obtain a grayscale image of the inspection piece;

[0154] Here, the image to be inspected for the inspection piece can be a red-green-blue (RGB) color image. Grayscale processing is a process of setting the RGB value of each pixel in a color image to 0 (black) or 255 (white), so that the original range of color values ​​changes from 256 to only black and white, resulting in a grayscale image of the inspection piece containing only black and white.

[0155] In some implementations, the image processing unit performs grayscale processing on the inspection patch image to convert the original color inspection patch image into a grayscale image, reducing the complexity of subsequent processing. The grayscale image of the inspection patch only contains brightness information, making subsequent inspection patch region identification easier.

[0156] Step S5312: Determine the grayscale difference between two adjacent pixels based on the grayscale values ​​corresponding to each pixel in the grayscale image;

[0157] In some implementations, the image processing unit determines the grayscale difference between adjacent pixels based on the grayscale value of each pixel in the grayscale image, which can highlight the edge features in the grayscale image. These edge features play a key role in the subsequent determination of target pixels and fitting of the inspection area.

[0158] Step S5313: The pixel corresponding to the gray level difference between two adjacent pixels being greater than the preset gray level threshold is determined as the target pixel.

[0159] Here, the preset grayscale threshold can be a suitable grayscale value set according to the grayscale value corresponding to each pixel in the inspection area and the grayscale value corresponding to each pixel in the electrode substrate area. The preset grayscale threshold can be 230, 235, 240, etc.

[0160] In some implementations, by setting a grayscale threshold, the image processing unit can identify target pixels when the grayscale difference between two adjacent pixels exceeds a preset grayscale threshold. These target pixels are the boundary points between the inspection patch area and the electrode substrate area, which helps the image processing unit accurately identify the inspection patch area.

[0161] Step S5314: Fit the target pixel points to obtain the spot detection area.

[0162] In some implementations, the boundaries of the inspection patch region can be obtained by fitting the target pixels using an image processing unit. The fitting process is typically based on mathematical methods (e.g., least squares method, polynomial fitting, etc.) that can smoothly connect the target pixels to form a complete inspection patch region.

[0163] In this embodiment of the present disclosure, on the one hand, the image processing unit determines the grayscale difference between two adjacent pixels based on the grayscale value of each pixel in the grayscale image of the inspection piece, which helps to improve the accuracy of subsequently determining the inspection piece area; on the other hand, by setting a grayscale threshold, pixels with a grayscale difference greater than the threshold can be selected as target pixels, which can effectively filter out the electrode substrate area, thereby improving the accuracy of the inspection piece area.

[0164] In some embodiments, the method may further include the following steps S511 and S512, wherein:

[0165] Step S511: Acquire light images of a linear light source captured by at least two cameras; the light images are obtained after the at least two cameras image the light rays that leak out onto both sides of the width of the electrode substrate generated by the linear light source, respectively; the electrode substrate includes an anode copper foil and a cathode aluminum foil.

[0166] Here, a portion of the light emitted by the linear light source leaks out from both sides of the electrode substrate, allowing the camera to capture an image of the light from the linear light source.

[0167] Step S512: If the grayscale value of each pixel in the light image is within a second preset range, it is determined that the linear light source is working normally.

[0168] Here, the second preset value range can be a suitable range set according to the grayscale value of the pixels in the light image, for example, 0 to 10.

[0169] In some implementations, the brightness of the light image is checked by the image processing unit to determine whether the linear light source is working properly. For example, if the grayscale value of each pixel in the light image is within a second preset range, it can be determined that the linear light source is working properly; if the grayscale value of each pixel in the light image is not within the second preset range, it can be determined that the linear light source is not working properly.

[0170] In this embodiment of the disclosure, by using an image processing unit to detect the light image of the linear light source based on the light image captured by the camera, problems can be detected before the performance of the linear light source deteriorates or fails, thereby enabling timely maintenance or replacement of the linear light source.

[0171] In some embodiments, the image processing unit performs pinhole detection on the image to be detected of the electrode substrate to obtain a pinhole detection result, which may include the following steps S5231 to S5234, wherein:

[0172] Step S5231: Preprocess each of the images to be detected on the electrode substrate to obtain the preprocessed images to be detected.

[0173] Here, preprocessing can be mean filtering, Gaussian filtering, median filtering, etc., the purpose of which is to make the image to be tested on the electrode substrate smoother and clearer, and to prevent tiny noise points from misjudging pinholes on the image to be tested on the electrode substrate.

[0174] Step S5232: Perform edge detection on each preprocessed image to be detected to obtain the electrode substrate region of each image to be detected.

[0175] In some implementations, by identifying the edge between the electrode substrate and the background in each preprocessed image to be detected by the image processing unit, the electrode substrate area and the background area can be accurately distinguished, thereby improving the accuracy of subsequent pinhole detection.

[0176] Step S5233: The electrode substrate regions are stitched together to obtain an electrode substrate image;

[0177] Here, since each line scan camera captures images of different areas of the electrode substrate to be detected, stitching together the electrode substrate areas of multiple images to be detected can yield a complete image of the electrode substrate. This ensures that the entire width and length of the electrode substrate are included in the image, thereby ensuring the comprehensiveness of pinhole detection.

[0178] Step S5234: Perform pinhole detection on the electrode substrate image to obtain pinhole detection results.

[0179] Here, as shown in Figure 6, there are pinholes of different sizes on the electrode substrate image 61 (three pinholes are shown in Figure 6). Since there are pinholes on the electrode substrate image, it is necessary to inspect the electrode substrate image to determine whether each pinhole on the electrode substrate image is qualified, and obtain the pinhole qualified inspection result or the pinhole unqualified inspection result.

[0180] In this embodiment of the disclosure, on the one hand, edge detection is performed on each pre-processed image to be detected of the electrode substrate by the image processing unit, which can accurately distinguish the electrode substrate area and the background area; on the other hand, pinhole detection is performed on the complete image of the electrode substrate, which can ensure that all pinholes on the electrode substrate are detected.

[0181] In some embodiments, the implementation of step S5234, "performing pinhole detection on the electrode substrate image to obtain pinhole detection results," may include the following steps S5341 and S5342, wherein:

[0182] Step S5341: Based on the grayscale value corresponding to each pixel in the electrode substrate image, determine the pinholes in the electrode substrate image and the size of each pinhole;

[0183] Here, the gray value of the pixel corresponding to the pinhole in the electrode substrate image is greater than the gray value of the pixels corresponding to other pixels.

[0184] In some implementations, the image processing unit can determine the pixel with the larger gray value from the electrode substrate image based on the different gray values ​​of each pixel in the electrode substrate image, and determine the pixel with the larger gray value as the pixel corresponding to the pinhole; when the size of each pixel is determined, the size of the corresponding pinhole can be determined based on the number of pixels corresponding to each pinhole.

[0185] Step S5342: If the difference between the size of each pinhole and the preset value is not within the second preset range, the pinhole is determined to be unqualified.

[0186] Here, the preset value can be a suitable value set according to the size of a normal pinhole, and the third preset range can be a suitable range set according to the size of each pinhole and the size of a normal pinhole, for example, 0 to 0.5 mm.

[0187] In some implementations, the size of each pinhole is subtracted from the size of a normal pinhole to obtain the difference between the size of each pinhole and the size of a normal pinhole; it is then determined whether each difference is within 0 to 0.5 mm. If there is a difference within 0 to 0.5 mm, then the pinhole corresponding to that difference is qualified; if there is a difference not within 0 to 0.5 mm, then the pinhole corresponding to that difference is unqualified.

[0188] In this embodiment of the present disclosure, the image processing unit detects whether each pinhole in the electrode substrate is qualified, and takes necessary measures in a timely manner to deal with unqualified pinholes, which helps to reduce the scrap rate and improve the quality of the electrode substrate.

[0189] This disclosure provides a backlight scanning detection system. By using a long linear light source to illuminate the back of an electrode substrate (e.g., aluminum foil), the line scanning camera takes line-by-line pictures of the front of the aluminum foil in sync with the movement of the aluminum foil. Some of the light generated by the linear light source passes through the pinholes in the aluminum foil, thus appearing as white spots in the line scan image. Other areas on the aluminum foil, except for the pinholes, are opaque and therefore appear as black in the line scan image.

[0190] This disclosure requires the detection of pinholes as small as 50 μm, with a device speed of 200 m / min. To prevent noise from interfering with pinhole detection on the aluminum foil image, a pinhole is described using a minimum of 2 pixels, requiring an accuracy of approximately 25 μm. This corresponds to a camera scanning frequency of 133,333.33, meaning the camera scans 133,333 lines per second. However, traditional 16K cameras (where K represents the resolution of a line scan camera) can only achieve 40 kHz, meaning they scan 40,000 lines per second, which is insufficient to meet the requirements.

[0191] This embodiment uses a novel 16K line scan camera with a CoaXPress interface. The maximum scanning frequency of this line scan camera can reach 250kHz. With the maximum width of the aluminum foil being 1700 mm, a precision of approximately 25 μm requires a design of 1700 mm × 1000 ÷ 25 μm = 68000 μm. 68000 μm ÷ 16384 ≈ 4.15. In other words, four 16K line scan cameras (with a resolution of 16384) are needed to work together. To ensure that the four 16K line scan cameras can completely cover the aluminum foil, the field of view of adjacent two 16K line scan cameras needs to partially overlap. The field of view of the two outermost 16K line scan cameras includes not only a portion of the aluminum foil area but also other areas. The distance between the two sides of the aluminum foil and the edge of the field of view of the line scan camera is 20mm. The fields of view of two adjacent line scan cameras overlap by 200mm. The field of view of each of the four 16K line scan cameras is 450mm. Thus, the accuracy of each line scan camera can reach 450mm÷16384=0.0275mm / pixel.

[0192] Because aluminum foil is opaque, the image of the aluminum foil captured by the camera appears completely black, making it impossible to use for inspection and verification. Furthermore, the camera may move during prolonged operation of the aluminum foil. To ensure inspection accuracy, this disclosure provides a film inspection method. This method requires removing the aluminum foil from the inspection station, placing a transparent film in the original position of the aluminum foil, and then attaching the film to the transparent film. This allows the outline of the film to be seen in the image captured by the camera. The film used in this disclosure for pinhole inspection is a black, opaque film with light-transmitting dots (i.e., the aforementioned pinholes) distributed on it. The film has excellent contrast and clarity, minimal error due to external interference, and high precision. To ensure inspection accuracy, the transparent film needs to be taut, smooth, and wrinkle-free during the unwinding process. The film adheres tightly to the surface of the transparent film, simulating the light-transmitting effect of pinholes on the film.

[0193] An inspection method provided in this embodiment, as shown in FIG7, may include the following steps S701 to S709, wherein:

[0194] In step S701, the encoder sends the generated pulse signal to multiple line scan cameras;

[0195] In step S702, after receiving the pulse signal, the multiple line scan cameras each acquire an image of the target area with a fixed line height of the corresponding region of the film.

[0196] Step S703: The vision host computer stitches together each image to be detected to obtain a stitched image.

[0197] Step S704: The visual host computer determines the film area based on the stitched image;

[0198] Here, the boundary between the film and the transparent film is a clear black and white boundary. The visual host computer can determine the four boundary lines of the film based on the gray values ​​of each pixel in the stitched image. By fitting the four boundary lines of the film, the film area can be obtained.

[0199] Step S705: The visual host computer determines the pinholes and the number of pinholes in the film based on the grayscale values ​​corresponding to each pixel in the film area.

[0200] Here, a grayscale threshold is set for pinholes in the film area. Pixels with grayscale values ​​greater than the grayscale threshold are selected from the film area and identified as target pixels. Pixels with a distance between two adjacent target pixels that is less than a preset value are connected end to end to obtain independent pinholes.

[0201] Step S706: The vision computer calculates the size of each pinhole and sorts the pinhole sizes from largest to smallest to obtain the sorting result.

[0202] In step S707, the vision host computer determines whether the difference between the size of each pinhole and the size of the standard pinhole is within a preset range; if yes, that is, the difference between the size of each pinhole and the size of the standard pinhole is within a preset range, proceed to step S708; if no, that is, the difference between the size of each pinhole and the size of the standard pinhole is not within a preset range, proceed to step S709.

[0203] Step S708: The vision host computer outputs a qualified signal;

[0204] Here, a qualified signal indicates that the number of pinholes is equal to the preset number of pinholes and the difference between the size of each pinhole and the size of the standard pinhole is within a preset range.

[0205] Step S709: The vision computer outputs an alarm signal.

[0206] Here, the alarm signal indicates that the number of pinholes is not equal to the preset number of pinholes, or the number of pinholes is equal to the preset number of pinholes but the difference between the size of each pinhole and the size of the standard pinhole is not within the preset range.

[0207] This disclosure provides a method for detecting pinholes in aluminum foil, as shown in FIG8. The pinhole detection method may include the following steps S801 to S807, wherein:

[0208] In step S801, the encoder sends the generated pulse signal to multiple line scan cameras;

[0209] Step S802: After receiving the pulse signal, the multiple line scan cameras generate line scan images of the corresponding areas of the aluminum foil with a fixed row height.

[0210] Step S803: The vision host computer preprocesses each line scan image to obtain the preprocessed line scan image.

[0211] Step S804: The vision host computer performs edge detection on each preprocessed line scan image to obtain the aluminum foil area of ​​each line scan image.

[0212] In step S805, the vision computer stitches together each aluminum foil area to obtain an aluminum foil image.

[0213] In step S806, the vision computer determines whether the size of each pinhole in the aluminum foil image is greater than a preset threshold. If yes, i.e., the pinhole size is greater than the preset threshold, proceed to step S807; otherwise, i.e., the pinhole size is less than or equal to the preset threshold, proceed to step S801. The preset threshold represents the acceptable range of pinhole sizes, for example, 0.5 mm.

[0214] In step S807, the PLC controls the marking machine to mark the defective pinholes.

[0215] Here, when the pinhole size is larger than the preset threshold, it indicates that there is a problem with large-sized pinhole light transmission in the aluminum foil. The vision computer outputs an alarm signal to the PLC, which then controls the marking machine to mark the corresponding position of the defective pinhole to indicate that there is an abnormality in the subsequent processes and equipment.

[0216] Compared with the prior art, the embodiments disclosed herein have the following advantages:

[0217] 1. The embodiments disclosed herein utilize the joint calibration of multiple 16K line scan cameras with CoaXPress interfaces to solve the problem that the field of view of a single line scan camera is too small to meet the large width requirement of aluminum foil, thus meeting the equipment production requirements while meeting the testing requirements.

[0218] 2. The field of view of each line scan camera in this embodiment is fixed and is compatible with aluminum foil of different sizes without any changes.

[0219] 3. In this embodiment of the present disclosure, the multiple line scan cameras are placed on the same bracket, and after fine adjustment, it can be ensured that each line scan camera captures the same row of aluminum foil.

[0220] 4. In this embodiment of the present disclosure, some of the light generated by the linear light source will leak out from both sides of the aluminum foil. The camera will capture an image of the light leaking out from the linear light source. By detecting the brightness of the light image, it can be determined whether the linear light source is working properly. Therefore, there is no need to worry about changes in the brightness of the light due to subjective operation, nor is it necessary to increase the workload of the inspection personnel by periodically checking the working status of the linear light source.

[0221] 5. The embodiments disclosed herein use a 16K line scan camera with a CoaXPress interface, which is more sensitive to the difference in grayscale values ​​between the aluminum foil and the light generated by the linear light source, and can more effectively distinguish the boundaries of the aluminum foil and the pinholes on the aluminum foil.

[0222] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence numbers of the above steps / processes do not imply a sequential order of execution; the execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure. The sequence numbers of the above embodiments of this disclosure are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0223] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0224] In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0225] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units; some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may all be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the integrated unit may be implemented in hardware or in a combination of hardware and software functional units.

[0226] The above description is merely an embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A strip hole detection system for detecting hole size information, comprising a light source assembly, at least one camera, and an image processing unit, wherein: The light source assembly is disposed on a first surface facing the material strip, and illuminates the material strip with light, and the area illuminated by the light source assembly is greater than the maximum width of the material strip; wherein, the material strip includes an electrode substrate; During inspection, the light source assembly illuminates the inspection piece carried on the material strip with light; the maximum width of the inspection piece is less than or equal to the width of the material strip; the inspection piece has holes of different sizes distributed on it, and the material strip carrying the inspection piece includes a notch that exposes at least the holes of the inspection piece. The at least one camera is positioned to capture images of the second surface of the material strip; the shooting range of the at least one camera is greater than the width of the material strip. The at least one camera is used to image the inspection piece under the illumination of the light source assembly; The image processing unit is used to detect the size information of the holes on the inspection piece based on the image to be inspected obtained by imaging, and to determine whether the inspection is successful. The camera is also used to image the strip under the illumination of the light source assembly if the inspection is successful. The image processing unit is further configured to detect the size information of the holes on the material strip based on the images of the material strip to be detected obtained by each of the cameras.

2. The strip hole detection system according to claim 1, wherein, The hole is a pinhole, and the light source assembly includes a linear light source; The inspection piece includes multiple pinholes arranged in an array with pinhole sizes ranging from large to small; The electrode substrate includes an anode copper foil and a cathode aluminum foil. The electrode substrate is provided with a notch corresponding to the pinhole on the inspection piece, so that light can pass through the pinhole on the inspection piece and enter the camera.

3. The strip hole detection system according to claim 1 or 2, wherein, The inspection piece is attached to the surface of the conveyor belt and moves using the conveyor belt as a moving carrier.

4. The strip hole detection system according to any one of claims 1 to 3, wherein, The inspection film is a film.

5. The strip hole detection system according to claim 2, wherein, The cameras include at least two units; The number of cameras is determined based on the maximum width of the electrode substrate, the minimum detection accuracy, and the resolution of the cameras; At least two cameras are set at equal intervals on the same bracket; The at least two cameras are used to image the inspection piece or the electrode substrate, respectively.

6. The strip hole detection system according to claim 5, wherein, The light source assembly includes a linear light source, and the range illuminated by the linear light source is greater than the width of the electrode substrate; The at least two cameras are also used to image light leaking from both sides of the width of the electrode substrate.

7. The strip hole detection system according to claim 6, wherein, The detection system also includes an encoder, a light source controller, and an image acquisition controller; The encoder is used to simultaneously send trigger signals to the light source controller and the image acquisition controller; The light source controller is used to control the linear light source to turn on in response to the trigger signal; The image acquisition controller is used to control the at least two cameras to acquire images at a preset frequency in response to the trigger signal.

8. The strip hole detection system according to any one of claims 5 to 7, wherein, The at least two cameras include at least two line scan cameras; The at least two line scan cameras are used to acquire one row of image data of the corresponding area of ​​the electrode substrate within the field of view; the acquisition of the row of image data is performed cyclically, and the image data with a preset number of rows is output as the image to be detected of the electrode substrate to the image processing unit.

9. The strip hole detection system according to claim 8, wherein, The detection system also includes a programmable logic controller and a marking machine; The image processing unit is further configured to perform pinhole detection on each of the images to be detected on the electrode substrate, obtain the corresponding pinhole detection result, and send the pinhole detection result to the programmable logic controller. The image processing unit is also used to obtain the pulse identifier corresponding to the defective pinhole; Based on the pulse identifier, a marking request is generated and sent to the programmable logic controller; The programmable logic controller is used to send a marking signal to the marking machine in response to the marking request; The marking machine is used to mark the defective pinholes in response to the marking signal.

10. A method for detecting holes in a strip, applied to a strip hole detection system, the strip hole detection system being used to detect the size information of holes, the strip hole detection system comprising a light source assembly, at least one camera, and an image processing unit; The detection method includes: In response to a trigger signal, an image acquisition controller controls at least one camera to image the inspection piece after it has been illuminated by a light source assembly; wherein, the light source assembly illuminates a first surface of the material strip or the inspection piece carried on the material strip, and the area illuminated by the light source assembly is greater than the maximum width of the material strip; the maximum width of the inspection piece is less than or equal to the width of the material strip; the inspection piece has holes of different sizes distributed on it, and the material strip carrying the inspection piece includes a notch that exposes at least the holes of the inspection piece; the at least one camera is positioned with its shooting direction facing a second surface of the material strip; the shooting range of the at least one camera is greater than the width of the material strip; the material strip includes an electrode substrate; The image acquisition controller outputs the image to be detected of the inspection piece obtained by the at least one camera to the image processing unit; The image processing unit detects the size information of the holes on the inspection piece based on the image to be inspected obtained by imaging, and determines whether the inspection is successful. If the inspection is successful, the image acquisition controller controls the camera to image the strip after the light source assembly illuminates it; The image acquisition controller outputs the images of the material strip to be detected obtained by each of the cameras to the image processing unit; The image processing unit detects the size information of the holes on the material strips based on the images to be detected of each material strip.

11. The method for detecting holes in a conveyor belt according to claim 10, wherein, The strip hole detection system further includes an encoder and a light source controller; the light source assembly includes a linear light source, and the at least one camera includes at least two line scan cameras; the method further includes: The encoder simultaneously sends trigger signals to the light source controller and the image acquisition controller; The light source controller, in response to the trigger signal, controls the linear light source to turn on; The image acquisition controller, in response to the trigger signal, controls the at least two line scan cameras to acquire images at a preset frequency; The at least two line scan cameras each acquire a line of image data corresponding to the area of ​​the electrode substrate within their field of view; the above acquisition steps are repeated, and the image data with a preset number of lines is output to the image processing unit as the image to be detected of the electrode substrate.

12. The method for detecting holes in a conveyor belt according to claim 10 or 11, wherein, The hole is a pinhole, and the method further includes: The image processing unit determines the inspection area based on the image to be detected of the inspection piece; Based on the grayscale value corresponding to each pixel in the inspection area, determine the pinholes and the number of pinholes in the inspection area. The size of each pinhole is determined based on each pixel in each pinhole; If the difference between the size of each pinhole and the preset pinhole size is within a first preset range, and the number of pinholes is equal to the actual number of pinholes on the inspection piece, then the inspection is determined to be successful.

13. The method for detecting holes in a conveyor belt according to claim 12, wherein, The image processing unit determines the inspection area based on the image to be detected of the inspection patch, including: The image to be inspected of the inspection piece is processed into grayscale to obtain the grayscale image of the inspection piece; Based on the gray value corresponding to each pixel in the grayscale image, the grayscale difference between two adjacent pixels is determined. The pixel that corresponds to the gray level difference between two adjacent pixels being greater than a preset gray level threshold is determined as the target pixel. The target pixel points are fitted to obtain the spot detection area.

14. The method for detecting voids in a conveyor belt according to any one of claims 10 to 13, wherein, The method further includes: Acquire light images of a linear light source from at least two cameras; the light images are obtained after the at least two cameras image the light rays that leak out onto both sides of the width of the electrode substrate generated by the linear light source. If the grayscale value of each pixel in the light image is within a second preset range, it is determined that the linear light source is working normally.

15. The method for detecting voids in a conveyor belt according to any one of claims 10 to 14, wherein, The number of cameras is determined based on the maximum width of the electrode substrate, the minimum detection accuracy, and the resolution of the cameras.

16. The method for detecting voids in a conveyor belt according to any one of claims 10 to 15, wherein, The image processing unit performs pinhole detection on the image to be detected on the electrode substrate to obtain pinhole detection results, including: Each of the images to be detected on the electrode substrate is preprocessed to obtain a preprocessed image to be detected. Edge detection is performed on each preprocessed image to be detected to obtain the electrode substrate region of each image to be detected. Each of the electrode substrate regions is stitched together to obtain an electrode substrate image; The electrode substrate image is subjected to pinhole detection to obtain pinhole detection results.

17. The method for detecting holes in a conveyor belt according to claim 16, wherein, Pinhole detection is performed on the electrode substrate image to obtain pinhole detection results, including: Based on the grayscale value corresponding to each pixel in the electrode substrate image, determine the pinholes in the electrode substrate image and the size of each pinhole; If the difference between the size of each pinhole and the preset value is not within the third preset range, the pinhole is determined to be unqualified.

18. The method for detecting holes in a conveyor belt according to claim 16 or 17, wherein, The inspection piece is a film, and the step of performing pinhole detection on the electrode substrate image to obtain pinhole detection results further includes: Based on the electrode substrate image, the film area is determined; based on the grayscale value corresponding to each pixel in the film area, the size and number of pinholes in the film are determined.

19. The method for detecting holes in a conveyor belt according to claim 18, wherein, The determination of the film area based on the electrode substrate image includes: The four boundary lines of the film are determined based on the grayscale values ​​of each pixel in the stitched image; The film region is obtained by fitting the four boundary lines of the film.

20. The method for detecting holes in a conveyor belt according to claim 17, wherein, The method further includes: The size of each pinhole is calculated and sorted from largest to smallest to obtain a sorting result; based on the sorting result, it is determined whether the difference between the size of each pinhole and a preset value is within the third preset range.

Images