A method, device, system and storage medium for detecting the lug of a lithium battery pole piece

Abstract

The present invention discloses a method, device, system and storage medium for detecting the pole lug of a lithium battery pole piece. By collecting an image of a pole piece to be detected, the pole piece to be detected is positioned and segmented and the center of gravity is detected according to the positional characteristics of the pole lug, and the outline of the pole lug to be detected and the area to be detected are obtained, so that the area to be detected is more closely fitted to the outline of the pole lug, and the problem of missed detection is avoided; by comparing and fitting the outline of the pole lug to be detected and the preset standard pole lug outline, a fitting result is obtained, and the detection situation is determined according to the fitting result, the area to be detected and the preset standard detection area. The detection method provided by the present invention compares and fits the standard pole lug outline generated by the standard process, thereby improving the stability of the detection capability, and at the same time, the area to be detected is divided into multiple areas, thereby improving the flexibility of adjusting the detection parameters.

Description

Technical Field

[0001] The present invention relates to the field of machine vision automated detection, and in particular to a method and device for detecting a tab of a lithium battery pole piece. Background Art

[0002] Lithium-ion batteries have the advantages of low self-discharge, high energy density, no memory effect, green environmental protection and long cycle life. The quality of the pole piece in the lithium battery production process determines the battery safety and endurance. Therefore, pole piece online defect detection is an important step in lithium battery quality inspection, and the pole ear detection is an important part of the pole piece inspection step.

[0003] The existing technology mostly uses the following two methods to detect the quality of the lug. The first is to compare the smoothness of the lug contours acquired through images to locate the abnormality of the lug edge; the second is to generate a standard lug detection area in advance through a standard process, and specifically search for lug abnormalities in the standard detection area.

[0004] However, both of the above technologies have inevitable defects. The first method is difficult to directly detect the quality of the lug through the contour, and the second method is difficult to flexibly adjust the detection area for pole pieces of different process sizes, which is prone to misjudgment. Summary of the invention

[0005] The present invention provides a method, device, system and storage medium for detecting a tab of a lithium battery pole piece, so as to achieve the technical effect of flexibly adjusting the detection area for tabs of different process sizes.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a method for detecting a tab of a lithium battery pole piece, comprising the following steps:

[0007] Collect an image of the pole piece to be detected, and perform positioning segmentation and center of gravity detection on the image of the pole piece to be detected according to the position characteristics of the pole ear to be detected, so as to obtain the outline of the pole ear to be detected and the area to be detected; wherein the area to be detected includes the bottom area of ​​the pole ear to be detected, the middle area of ​​the pole ear to be detected and the top area of ​​the pole ear to be detected;

[0008] The fitting result is obtained by comparing and fitting the preset standard tab contour with the tab contour to be detected, and the detection condition of the tab to be detected is determined according to the fitting result, the area to be detected and the preset standard detection area.

[0009] The detection method provided by the present invention locates, segments and detects the center of gravity of the collected complete image of the pole piece to be detected according to the position characteristics of the pole ear, and thereby obtains the outline of the pole ear to be detected and the area to be detected, which provides a data basis for the subsequent detection of the pole ear to be detected through the standard pole ear outline and detection area, and also realizes the quality detection of the pole ear to be detected through the center of gravity detection, thereby making the data obtained by the detection more accurate.

[0010] The pole lug to be inspected is inspected by comparing the fitted contour of the pole lug to be inspected with the preset standard pole lug contour, so that the obtained fitting result is more accurate. At the same time, since the standard pole lug contour is calculated based on the standard pole lug data, when the pole lug is inspected according to this method, the detection capability is not affected by the fluctuation of the pole lug contour during actual production.

[0011] The detection condition of the pole lug to be detected is determined according to the fitting result, the area to be detected and the standard detection area, and the detection condition of the pole lug to be detected is further determined, so that the user can directly determine the detection result of the pole lug to be detected according to the detection condition.

[0012] As a preferred example, the positioning segmentation and center of gravity detection of the image of the pole piece to be detected are performed according to the position characteristics of the pole lug to be detected, specifically:

[0013] According to the positional features of the pole lug to be detected, it is determined that the pole lug to be detected is located outside the edge of the pole piece to be detected and is connected to the edge of the pole piece to be detected, and the image of the pole piece to be detected is positioned and segmented by threshold segmentation and region segmentation to determine the contour of the pole lug to be detected;

[0014] The connection between the lug root of the lug to be detected and the pole piece to be detected is located and screened, and the center of gravity detection is performed on the connection by a preset center of gravity detection method to determine the area to be detected of the lug to be detected.

[0015] The method for positioning, segmenting and detecting the center of gravity of the pole ear provided by the present invention determines the specific position of the pole ear to be detected in the pole piece to be detected through the position feature of the pole ear, which is outside the edge of the pole piece to be detected and connected to the pole piece to be detected, thereby realizing accurate positioning of the pole ear to be detected and providing a data basis for the later segmentation of the standard pole piece to be detected to obtain the pole ear to be detected.

[0016] According to the precise positioning of the pole ear to be detected provided by the above method, the pole piece to be detected is segmented by threshold segmentation and area segmentation to obtain the pole ear contour corresponding to the pole ear to be detected. The pole ear image to be detected obtained by segmentation by the above two methods is more in line with the real pole ear to be detected, thereby making the detection result more accurate; at the same time, the above two methods are used to segment the pole ear to be detected, which also improves the integrity and accuracy of the segmentation of the pole ear to be detected; the obtained pole ear contour to be detected provides a data basis for later detection.

[0017] At the same time, the connection between the pole ear root and the pole piece to be detected is re-located for the segmented pole ear, and the center of gravity detection is performed on the connection according to the preset center of gravity detection method to determine the area to be detected of the pole ear to be detected. The present invention realizes the detection of the quality of the pole ear to be detected through the center of gravity detection method, and the area to be detected obtained at the same time provides a data basis for subsequent comparison and fitting.

[0018] As a preferred example, the center of gravity detection is performed on the connection point by a preset center of gravity detection method to determine the detection area of ​​the tab to be detected, specifically:

[0019] Determine the center of gravity of the connection according to the result of the center of gravity detection, use the center of gravity of the connection as the first row coordinate of the pole lug to be detected, and determine the first column coordinate of the pole lug to be detected according to the contour of the pole lug to be detected;

[0020] The first upper intersection point coordinates and the first lower intersection point coordinates are calculated and determined according to the first row coordinates and the first column coordinates, and the area to be detected is determined according to the first upper intersection point coordinates and the first lower intersection point coordinates.

[0021] The present invention determines the center of gravity of the connection according to the above-mentioned center of gravity detection method, determines the center of gravity as the first row coordinate of the pole ear to be detected, and then determines the first column coordinate of the pole ear to be detected according to the contour of the pole ear to be detected, and after determination, calculates the first upper intersection point coordinate and the first lower intersection point coordinate according to the above two coordinates, and the detection area of ​​the pole ear to be detected can be determined according to the above two intersection point coordinates. The detection area determined according to the above-mentioned intersection point coordinates makes the detection area more in line with the detection requirements and closer to the contour of the pole ear to be detected, thereby avoiding the situation of missed detection of the pole piece.

[0022] The area to be detected determined according to the above two intersection points includes the top area of ​​the pole lug to be detected, the middle area of ​​the pole lug to be detected and the bottom area of ​​the pole lug to be detected. The above three areas to be detected correspond to the standard detection areas respectively. At the same time, the contour of the pole lug to be detected is divided into three parts, and different detection threshold intervals are set for these three parts, so that the detection of the pole lug to be detected is more flexible, and thereby the parameter standard and detection range of the corresponding detection area can be flexibly adjusted for the pole lugs to be detected with different process sizes.

[0023] As a preferred example, the first upper intersection point coordinates and the first lower intersection point coordinates are calculated and determined according to the first row coordinates and the first column coordinates. Specifically:

[0024] Determine a first upper tangent circle and a second upper tangent circle according to the first row coordinate and the first column coordinate, determine that the flush side of the electrode piece to be detected is connected to the top side of the electrode tab to be detected through the first upper tangent circle, and determine that the top side of the electrode tab to be detected is connected to the oblique side through the second upper tangent circle;

[0025] After determination, the intersection point of the second upper tangent circle and the hypotenuse of the pole ear to be detected is taken as the first upper intersection point, and the coordinates of the first upper intersection point are obtained;

[0026] Determine a first undercut circle and a second undercut circle according to the first row coordinate and the first column coordinate, determine that the flush side of the electrode piece to be detected is connected to the bottom side of the electrode tab to be detected through the first undercut circle, and determine that the bottom side of the electrode tab to be detected is connected to the oblique side through the second undercut circle;

[0027] After the determination, the second lower cutting circle and the hypotenuse of the pole ear to be detected are taken as the first lower intersection point, and the coordinates of the first lower intersection point are obtained.

[0028] The method provided by the present invention for determining the area to be detected based on the left side of the first row and the left side of the first column determines the first upper circle, the first lower circle, the second upper circle and the second lower circle by the first row coordinates and the first column coordinates, and the intersection points of the second upper circle and the second lower circle with the hypotenuse of the pole ear to be detected are the first upper intersection point and the first lower intersection point, respectively.

[0029] At the same time, the method for determining the area to be detected provided by the present invention also includes determining the connection mode of the straight edge of the electrode to be detected and the top edge, bottom edge and oblique edge of the electrode ear to be detected. Only after the above connection modes are determined can the above two intersection coordinates be determined. Since the connection mode requirements between the electrode ears of the electrode sheets generated by the standard process are also very strict, the determination step provided by the present invention further improves the accuracy of the electrode ear detection and ensures that the connection mode of the electrode ears after detection also meets the requirements of the standard process.

[0030] As a preferred example, the fitting result is obtained by comparing and fitting the standard tab profile with the tab profile to be tested, specifically:

[0031] Locate the top region of the pole lug to be detected, compare and fit the contour of the pole lug to be detected in the top region of the pole lug to be detected and the contour of the standard pole lug corresponding to the standard detection region, and obtain a fitting result of the top of the pole lug to be detected;

[0032] Locating the middle region of the standard pole lug, comparing and fitting the pole lug contour in the middle region of the standard pole lug and the pole lug contour to be detected in the middle region of the pole lug to be detected, and obtaining a fitting result of the middle region of the pole lug to be detected;

[0033] The standard tab bottom region is located, and the tab contour within the standard tab bottom region is compared and fitted with the tab contour to be detected within the corresponding tab bottom region to obtain a fitting result of the tab bottom to be detected.

[0034] The method for obtaining fitting results by comparative fitting provided by the present invention compares the tab contours contained in the corresponding two areas according to the corresponding relationship between the preset standard detection area and the area to be detected, and then obtains the fitting results of the corresponding areas. The detection logic of the detection method is simple and convenient, and because the partial tab contours contained in each detection area are different, the user can make adjustments as needed to flexibly adjust the detection range and parameter standards corresponding to each detection area, thereby realizing flexible adjustment of the parameter standards and detection range of the corresponding detection area for the tabs to be detected with different process sizes.

[0035] As a preferred example, the detection condition of the tab to be detected is determined according to the fitting result, the area to be detected and the preset standard detection area, specifically:

[0036] Comparing the fitting result of the area to be detected with a first threshold interval preset for the corresponding detection area; wherein the first threshold interval includes an outward expansion threshold interval and an inward contraction threshold interval;

[0037] If the fitting result is less than or equal to the first threshold interval of the corresponding detection area, the detection of the electrode tab to be detected passes;

[0038] If one or more of the fitting results are greater than the first threshold interval of the corresponding detection area, the detection of the electrode tab to be detected fails.

[0039] The method for detecting according to the fitting results provided by the present invention performs detection by comparing the fitting results of each area to be detected with the first threshold interval of the corresponding detection area. The method is simple and clear to implement, and the user can adaptively adjust the threshold interval according to actual needs to avoid setting the interval threshold too small, resulting in a high failure rate of the pole ear to be detected, and at the same time avoid setting the interval threshold too large, resulting in a low passing standard of the pole ear to be detected, thereby affecting the battery safety and endurance of the human lithium battery.

[0040] At the same time, the two different threshold ranges provided by the present invention provide a data basis for later judgment of the specific detection conditions of the tab to be detected.

[0041] As a preferred example, if one or more of the fitting results are greater than the first threshold interval of the corresponding detection area, the detection of the tab to be detected fails, specifically including:

[0042] If the fitting result is greater than the outer expansion threshold interval of the corresponding detection area, it is determined that the pole tab to be detected is a pole tab remnant and the pole tab to be detected fails the detection;

[0043] If the fitting result is greater than the shrinkage threshold interval of the corresponding detection area, it is determined that the pole lug to be detected is damaged and the pole lug to be detected fails the detection;

[0044] Among them, the outward expansion threshold interval is the basis for judging whether the pole tab is the pole tab remnant; the inward contraction threshold interval is the basis for judging whether the pole tab is the pole tab damaged.

[0045] The present invention also provides a method for determining the specific reasons why the failed tabs need to be returned to the factory for rework based on the above-mentioned fitting results in combination with the area to be inspected and the standard inspection area, and by judging the specific reasons why the tab inspection fails, it is possible to judge whether there are any areas in the tab processing machine that need repair.

[0046] The two threshold intervals provided by the present invention can be set by the user, and the user can flexibly adjust the specific parameters of the above two threshold intervals according to needs to ensure the accuracy of the final detection result.

[0047] Correspondingly, the present invention also provides a pole ear detection device for a lithium battery pole piece, the detection device comprising the following modules: an image acquisition module, a comparison and fitting module;

[0048] The image acquisition module is used to acquire the image of the pole piece to be detected, and according to the position characteristics of the pole ear to be detected, the image of the pole piece to be detected is positioned, segmented and the center of gravity is detected to obtain the outline of the pole ear to be detected and the area to be detected; wherein the area to be detected includes the bottom area of ​​the pole ear to be detected, the middle area of ​​the pole ear to be detected and the top area of ​​the pole ear to be detected;

[0049] The comparison and fitting module is used to obtain a fitting result by comparing and fitting a preset standard tab contour with the tab contour to be detected, and determine the detection status of the tab to be detected based on the fitting result, the area to be detected and the preset standard detection area.

[0050] The present invention provides a lithium battery pole piece tab detection device, which can implement any of the above-mentioned detection methods.

[0051] Correspondingly, the present invention also provides a tab detection system for a lithium battery pole piece, the detection system comprising a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements any of the above-mentioned methods for detecting a tab of a lithium battery pole piece when processing the computer program.

[0052] The memory of a lithium battery pole piece lug detection system provided by the present invention stores a computer program that can implement any one of the above-mentioned detection methods, and the computer program of any one of the above-mentioned detection methods can be executed by a processor of the detection system.

[0053] Correspondingly, the present invention also provides a computer readable storage medium, on which a computer program is stored. When the computer program is run by a processor, the method for detecting a tab of a lithium battery pole piece as described in any one of the above items is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 : A schematic flow chart of an embodiment of a method for detecting a pole lug of a lithium battery pole piece provided by the present invention;

[0055] Figure 2 : A schematic flow chart of an embodiment of a method for obtaining a tab profile to be detected and an area to be detected provided by the present invention;

[0056] Figure 3 : A flow chart of an embodiment of a method for determining the coordinates of the first upper intersection point and the first lower intersection point provided by the present invention;

[0057] Figure 4 : A schematic flow chart of an embodiment of a method for obtaining fitting results of a tab to be detected provided by the present invention;

[0058] Figure 5 : A flow chart of an embodiment of determining a detection condition according to a fitting result provided by the present invention;

[0059] Figure 6 : A structural schematic diagram of an embodiment of a tab detection device for a lithium electrode sheet provided by the present invention. DETAILED DESCRIPTION

[0060] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] Embodiment 1

[0062] Please refer to Figure 1 , is a flow chart of an embodiment of a method for detecting a pole ear of a lithium battery pole piece provided by an embodiment of the present invention, including steps 101 to 102, each step is specifically as follows:

[0063] Step 101: Acquire an image of a pole piece to be detected, and perform positioning segmentation and center of gravity detection on the image of the pole piece to be detected according to the positional features of the pole lug to be detected, so as to obtain the outline of the pole lug to be detected and the area to be detected.

[0064] In this embodiment, by collecting the image of the pole piece to be detected and the position characteristics of the pole ear relative to the pole piece, the pole ear contour of the pole ear to be detected and the area to be detected corresponding to the pole ear to be detected are obtained by positioning segmentation and center of gravity detection methods, providing a data basis for later detection. The present invention does not further limit the specific method of collecting images, and the user can adjust the image collection method according to actual needs. However, the image collection method of this embodiment is preferably connected to the image acquisition card through the CameraLink communication protocol by a line scan camera, and the image acquisition card is also interconnected with the encoder of the relevant equipment. When the encoder rotates, it triggers the line scan camera to send a capture signal to the image acquisition card, and the complete image of the pole piece to be detected is collected under the irradiation of a preset appropriate light source.

[0065] The CameraLink communication protocol is a communication protocol specifically designed for the field of machine vision, using low voltage differential signal LVDS for transmission. It adds 6 pairs of differential signal lines based on the ChannelLink standard, 4 pairs of which are used for parallel transmission of camera control signals, and the remaining two pairs are used for serial communication between cameras, image acquisition cards or other image receiving devices.

[0066] Step 102: Obtain a fitting result by comparing and fitting a preset standard tab contour with the tab contour to be detected, and determine the detection condition of the tab to be detected based on the fitting result, the area to be detected and the preset standard detection area.

[0067] In this embodiment, the pole lug to be inspected is inspected by comparing the contour of the fitted pole lug to be inspected with the preset standard pole lug contour, so that the obtained fitting result is more accurate. At the same time, since the standard pole lug contour is calculated based on the standard pole lug data, when the pole lug is inspected according to this method, the detection capability is not affected by the fluctuation of the pole lug contour during actual production.

[0068] The detection condition of the pole lug to be detected is determined according to the fitting result, the area to be detected and the standard detection area, and the detection condition of the pole lug to be detected is further determined, so that the user can directly determine the detection result of the pole lug to be detected according to the detection condition.

[0069] In summary, the detection method provided in this embodiment determines the lug contour and the area to be detected of the lug to be detected by positioning, segmenting and detecting the center of gravity of the pole piece to be detected, and provides a data basis for subsequent comparison and fitting, while also detecting the quality of the lug, thereby making the detection result more accurate. Since the standard lug contour used for comparing and fitting the lug contour to be detected in this embodiment is generated according to the standard process, it is not affected by the errors generated during the actual production of the lug during detection, thereby making the obtained detection result more accurate and more in line with the needs of users. At the same time, this embodiment also provides further analysis and detection of the fitting results, which is convenient for users to analyze and judge the lug detection results based on further detection conditions.

[0070] As another example of this embodiment, see Figure 2 , Figure 2 A schematic flow chart of an embodiment of a method for obtaining a tab profile to be detected and a region to be detected provided by the present invention includes steps 201 to 203, each of which is specifically as follows:

[0071] Step 201: According to the positional features of the pole lug to be detected, it is determined that the pole lug to be detected is located outside the edge of the pole piece to be detected and is connected to the edge of the pole piece to be detected, and the image of the pole piece to be detected is positioned and segmented by threshold segmentation and area segmentation to determine the contour of the pole lug to be detected.

[0072] In this example, the specific position of the pole ear to be detected in the pole piece to be detected is determined by the pole ear position feature to be outside the edge of the pole piece to be detected and connected to the pole piece to be detected, so as to achieve accurate positioning of the pole ear to be detected, and provide a data basis for later segmentation of the standard pole piece to be detected to obtain the pole ear to be detected. In this embodiment, the pole ear to be detected is located outside the edge of the pole piece to be detected and is smoothly connected to the pole piece to be detected. Whether the connection is smooth is also a major focus of later detection.

[0073] The smooth connection means that the bottom edge and the top edge of the pole ear to be detected are connected flush with the pole piece to be detected through an arc with a certain radius.

[0074] According to the precise positioning of the pole ear to be detected provided by the above method, the pole piece to be detected is segmented by threshold segmentation and area segmentation to obtain the pole ear contour corresponding to the pole ear to be detected. The pole ear image to be detected obtained by segmentation by the above two methods is more in line with the real pole ear to be detected, thereby making the detection result more accurate; at the same time, the above two methods are used to segment the pole ear to be detected, which also improves the integrity and accuracy of the segmentation of the pole ear to be detected; the obtained pole ear contour to be detected provides a data basis for later detection.

[0075] Step 202: locate and select the connection between the root of the pole lug to be detected and the pole piece to be detected, perform center of gravity detection on the connection by a preset center of gravity detection method, determine the center of gravity of the connection according to the result of the center of gravity detection, use the center of gravity of the connection as the first row coordinate of the pole lug to be detected, and determine the first column coordinate of the pole lug to be detected according to the contour of the pole lug to be detected.

[0076] In this example, the center of gravity of the connection is determined by the center of gravity detection method, and the determined center of gravity is used as the first row coordinate of the pole ear to be detected. After determination, the first column coordinate is determined according to the contour of the pole ear to be detected, providing a data basis for later determining the left side of the intersection of the two items.

[0077] Step 203: Calculate and determine the first upper intersection point coordinates and the first lower intersection point coordinates according to the first row coordinates and the first column coordinates, and determine the area to be detected according to the first upper intersection point coordinates and the first lower intersection point coordinates

[0078] In this example, the connection between the pole ear root and the pole piece to be detected is located again by segmenting the pole ear to be detected, and the center of gravity detection is performed on the connection according to the preset center of gravity detection method. The center of gravity of the connection is determined according to the center of gravity detection method, and the center of gravity is determined as the first row coordinate of the pole ear to be detected. Then, the first column coordinate of the pole ear to be detected is determined according to the contour of the pole ear to be detected. After determination, the first upper intersection point coordinate and the first lower intersection point coordinate are calculated according to the above two coordinates. The detection area of ​​the pole ear to be detected can be determined according to the above two intersection point coordinates. On the one hand, this embodiment realizes the detection of the quality of the pole ear to be detected through the center of gravity detection method, and on the other hand, the detection area is obtained to provide a data basis for later comparison and fitting.

[0079] Similarly, the method of determining the intersection point based on the above-mentioned center of gravity and determining the area to be inspected by the intersection coordinates makes the area to be inspected more in line with the inspection requirements and closer to the contour of the pole ear to be inspected, thereby avoiding the situation of missed inspection of the pole piece.

[0080] The area to be detected determined according to the above two intersection points includes the top area of ​​the pole lug to be detected, the middle area of ​​the pole lug to be detected and the bottom area of ​​the pole lug to be detected. The above three areas to be detected correspond to the standard detection areas respectively. At the same time, the contour of the pole lug to be detected is divided into three parts, and different detection threshold intervals are set for these three parts, so that the detection of the pole lug to be detected is more flexible, and thereby the parameter standard and detection range of the corresponding detection area can be flexibly adjusted for the pole lugs to be detected with different process sizes.

[0081] As another example of this embodiment, see Figure 3 , Figure 3A flow chart of an embodiment of a method for determining the coordinates of a first upper intersection point and a first lower intersection point provided by the present invention includes steps 301 to 304, wherein step 301 is similar to step 303, and step 302 is similar to step 304, steps 301 to 302 determine the coordinates of the first upper intersection point, and steps 303 to 304 determine the coordinates of the first lower intersection point.

[0082] This example provides a method for determining the area to be detected based on the left side of the first row and the left side of the first column, wherein the first upper circle, the first lower circle, the second upper circle and the second lower circle are determined by the first row coordinates and the first column coordinates, and the intersection points of the second upper circle and the second lower circle with the hypotenuse of the pole ear to be detected are the first upper intersection point and the first lower intersection point, respectively.

[0083] At the same time, the method for determining the area to be detected provided by the present invention also includes determining the connection mode of the straight edge of the electrode to be detected and the top edge, bottom edge and oblique edge of the electrode ear to be detected. Only after the above connection modes are determined can the above two intersection coordinates be determined. Since the connection mode requirements between the electrode ears of the electrode sheets generated by the standard process are also very strict, the determination step provided by the present invention further improves the accuracy of the electrode ear detection and ensures that the connection mode of the electrode ears after detection also meets the requirements of the standard process.

[0084] Further, regarding a specific implementation of an embodiment of the present invention, the key parameters of the pole ear to be detected are determined by the contour of the pole ear to be detected, including the bottom width w0, the top width w1, the hypotenuse length l, the first upper cutting circle radius r0 and the second upper cutting circle radius r1, the first angle α1 between the first upper cutting circle and the edge of the pole piece to be detected, the second angle β between the hypotenuse of the pole ear to be detected and the edge of the pole piece to be detected, and the third angle α0 between the first lower cutting circle and the pole piece to be detected. Then, according to the above key parameters and the first row coordinate Row0 and the first column coordinate Column0, the first upper intersection point coordinate p1 and the first lower intersection point coordinate p 01 , and finally determine the area to be detected. The specific calculation method is as follows:

[0085] The first intersection coordinate θ1 (Row1, Column1) is calculated and determined according to the first row coordinate Row0, the first column coordinate Column0 and the bottom width w0 of the pole ear to be detected:

[0086] Row1=Row0,Column1=Column0+w0 / 2

[0087] The center coordinates R0 (Row 0) of the first upper circle are determined according to the first intersection point coordinates θ1, the radius r0 of the first upper circle, and the first angle α1. r0 , Column r0 ):

[0088] Row r0 =Row1+r0*cosα1,Column r0 =Column1+r0*sina1

[0089] The second intersection point coordinate θ2 (Row2, Column2) is determined according to the center coordinate R0 of the first upper tangent circle, the radius r0 of the first upper tangent circle, and the second angle β:

[0090] Row2=Row r0 +r0*sin(180-β),Column2=Column r0 +r0*cos(180-β)

[0091] Determine the third intersection coordinate θ3 (Row3, Column3) according to the second intersection coordinate θ2, the hypotenuse length l, and the second angle β:

[0092] Row3=Row2+l*cos(180-β),Column3=Column2+l*sin(180-β)

[0093] Determine the center coordinates R1 (Row 3 ) of the second upper circle according to the third intersection point coordinates θ3, the radius r1 of the second upper circle, and the second angle β. r1 , Column r1 ):

[0094] Row r1 =Row3+r1*sin(180-β),Column r1 = Column3-r1*cos(180-β)

[0095] According to the coordinates of the center of the second upper circle Row r1 The radius r1 of the second upper tangent circle and the first angle α1 determine the coordinates of the first upper intersection point p1 (Row p1 , Column p1 ):

[0096] Row p1 =Row r1 -r1*cosα1,Column p1 =Column r1 +r1*sina1

[0097] In summary, the coordinates of the first upper intersection point can be obtained, and the calculation method of the coordinates of the first lower intersection point is consistent with the calculation method of the coordinates of the first upper intersection point. Similarly, the coordinates of the first lower intersection point can also be obtained symmetrically through the first row coordinates and the first column coordinates of the pole lug according to the symmetry of the pole lug. After obtaining the above two intersection points, the pole lug to be detected is divided into three areas to be detected according to the horizontal coordinates of the above two intersection points, including the top area of ​​the pole lug to be detected, the middle area of ​​the pole lug to be detected, and the bottom area of ​​the pole lug to be detected.

[0098] As another example of this embodiment, see Figure 4 , Figure 4 A flow chart of an embodiment of a method for obtaining a fitting result of a pole ear to be detected provided by the present invention includes steps 401 to 403, and the above three steps can be performed simultaneously or in sequence. The three areas to be detected determined by the above calculation can divide the contour of the pole ear to be detected into three parts, and the corresponding three preset standard detection areas can also divide the preset standard pole ear contour into three parts. By comparing and fitting the contour of the pole ear to be detected in the area to be detected and the standard pole ear contour of the corresponding standard detection area, three corresponding fitting results can be obtained.

[0099] The method for obtaining fitting results by comparative fitting provided in the present embodiment compares the ear contours contained in the two corresponding areas according to the correspondence between the preset standard detection area and the area to be detected, and then obtains the fitting results of the corresponding areas. The detection logic of the detection method is simple and convenient, and because the partial ear contours contained in each detection area are different, the user can make adjustments as needed to flexibly adjust the detection range and parameter standards corresponding to each detection area, thereby realizing flexible adjustment of the parameter standards and detection range of the corresponding detection area for the ears to be detected with different process sizes.

[0100] As another example of this embodiment, see Figure 5 , Figure 5 A flowchart of an embodiment of determining a detection situation according to a fitting result provided by the present invention specifically includes steps 501 to 503.

[0101] like Figure 5 As shown, the fitting result of the area to be detected is compared with the first threshold interval of the corresponding detection area, and whether the pole ear to be detected passes the detection is determined according to the comparison result, wherein the first threshold interval includes an outward expansion threshold interval and an inward contraction threshold interval. If the fitting result is less than or equal to the first threshold interval of the corresponding detection area, the pole ear to be detected passes the detection; if one or more of the fitting results is greater than the first threshold interval of the corresponding detection area, the pole ear to be detected fails the detection.

[0102] The method for detecting according to the fitting results provided in the embodiment of the present invention performs detection by comparing the fitting results of each area to be detected with the first threshold interval of the corresponding detection area. The method is simple and clear to implement, and the user can adaptively adjust the threshold interval according to actual needs to avoid setting the interval threshold too small, resulting in too high a failure rate of the pole ear to be detected, and at the same time avoid setting the interval threshold too large, resulting in too low a passing standard of the pole ear to be detected, thereby affecting the battery safety and endurance of the human lithium battery.

[0103] At the same time, the two different threshold ranges provided in this embodiment provide a data basis for later judgment of the specific detection conditions of the tab to be detected.

[0104] Among them, for the part of the pole ear to be detected that fails the inspection, if the fitting result is greater than the outward expansion threshold interval of the corresponding detection area, it is determined that the pole ear to be detected is pole ear remnant and the pole ear to be detected fails the inspection; if the fitting result is greater than the inward contraction threshold interval of the corresponding detection area, it is determined that the pole ear to be detected is a damaged pole ear and the pole ear to be detected fails the inspection.

[0105] Correspondingly, for the detection of the outward expansion of the three parts of the area to be detected, if there is a first grayscale value higher than the preset first grayscale threshold in the area to be detected during comparison and fitting, the part higher than the first grayscale threshold will be judged as the residual material area, and if there is a residual material area in a certain area to be detected that is larger than the preset outward expansion threshold interval of the corresponding standard detection area, then the pole ear to be detected will be judged as the pole ear residual material, and therefore the detection will fail.

[0106] For the shrinkage detection of the three parts of the area to be detected, if there is a second grayscale value higher than the preset second grayscale threshold in the area to be detected during comparison fitting, the part higher than the second grayscale threshold will be judged as a damaged area; if there is a damaged area in a certain area to be detected that is larger than the preset shrinkage threshold interval of the corresponding standard detection area, the pole ear to be detected will be judged as a damaged pole ear, and therefore the detection will fail.

[0107] This embodiment also provides a method for determining the specific reasons why the failed tabs need to be returned to the factory for rework based on the above-mentioned fitting results in combination with the area to be inspected and the standard inspection area, and by judging the specific reasons why the tab inspection fails, it is possible to judge whether there are any areas in the tab processing machine that need repair.

[0108] The two threshold intervals provided by the present invention can be set by the user, and the user can flexibly adjust the specific parameters of the above two threshold intervals according to needs to ensure the accuracy of the final detection result.

[0109] In order to better illustrate the working principle and step flow of the method, device, system and storage medium for detecting the tab of a lithium battery electrode of the present invention, including but not limited to the relevant records above.

[0110] Accordingly, see Figure 6 , Figure 6 A schematic diagram of the structure of an embodiment of a tab detection device for a lithium electrode sheet provided by the present invention, such as Figure 6 As shown, the detection device includes: an image acquisition module 601 and a comparison and fitting module 602.

[0111] Among them, the image acquisition module 601 is used to acquire the image of the pole piece to be detected, and according to the position characteristics of the pole ear to be detected, the image of the pole piece to be detected is located, segmented and the center of gravity detected to obtain the contour of the pole ear to be detected and the area to be detected; wherein the area to be detected includes the bottom area of ​​the pole ear to be detected, the middle area of ​​the pole ear to be detected and the top area of ​​the pole ear to be detected.

[0112] The comparison and fitting module 602 is used to obtain a fitting result by comparison and fitting a preset standard tab contour and a tab contour to be detected, and determine the detection status of the tab to be detected based on the fitting result, the area to be detected and the preset standard detection area.

[0113] The present embodiment provides a lithium battery pole piece tab detection device, which can implement any of the above-mentioned detection methods.

[0114] Correspondingly, this embodiment also provides a tab detection system for a lithium battery pole piece, the detection system comprising a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements any of the above-mentioned methods for detecting a tab of a lithium battery pole piece when processing the computer program.

[0115] The memory of a lithium battery pole piece tab detection system provided in this embodiment stores a computer program that can implement any one of the above-mentioned detection methods, and the computer program of any one of the above-mentioned detection methods can be executed by the processor of the detection system.

[0116] Correspondingly, this embodiment further provides a computer readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, a method for detecting a tab of a lithium battery pole piece as described in any one of the above items is executed.

[0117] In summary, the present invention provides a method, device, system and storage medium for detecting the lugs of lithium battery pole pieces, by collecting images of the pole piece to be detected, positioning and segmenting the pole piece to be detected and detecting the center of gravity according to the positional features of the lug, obtaining the lug contour to be detected and the area to be detected, so that the area to be detected is more closely fitted to the lug contour, avoiding the problem of missed detection; by comparing and fitting the lug contour to be detected and the preset standard lug contour, obtaining the fitting result, and determining the detection situation according to the fitting result, the area to be detected and the preset standard detection area. The detection method provided by the present invention compares and fits the standard lug contour generated by the standard process, thereby improving the stability of the detection capability, and at the same time, the area to be detected is divided into multiple areas, thereby improving the flexibility of adjusting the detection parameters.

[0118] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for detecting a pole ear of a lithium battery pole piece, characterized in that: The following steps are involved: Collect an image of the pole piece to be detected, and perform positioning segmentation and center of gravity detection on the image of the pole piece to be detected according to the position characteristics of the pole ear to be detected, so as to obtain the outline of the pole ear to be detected and the area to be detected; wherein the area to be detected includes the bottom area of ​​the pole ear to be detected, the middle area of ​​the pole ear to be detected and the top area of ​​the pole ear to be detected; Obtaining a fitting result by comparing and fitting a preset standard tab profile with the tab profile to be detected, and determining the detection condition of the tab to be detected according to the fitting result, the area to be detected and the preset standard detection area; The positioning, segmentation and center of gravity detection of the image of the pole piece to be detected are performed according to the position characteristics of the pole lug to be detected, specifically: According to the positional features of the pole lug to be detected, it is determined that the pole lug to be detected is located outside the edge of the pole piece to be detected and is connected to the edge of the pole piece to be detected, and the image of the pole piece to be detected is positioned and segmented by threshold segmentation and region segmentation to determine the contour of the pole lug to be detected; Locate and select the connection between the lug root of the lug to be detected and the pole piece to be detected, perform a gravity center detection on the connection by a preset gravity center detection method, and determine the detection area of ​​the lug to be detected; The method of performing a gravity center detection on the connection point by a preset gravity center detection method to determine the detection area of ​​the electrode tab to be detected is specifically as follows: Determine the center of gravity of the connection according to the result of the center of gravity detection, use the center of gravity of the connection as the first row coordinate of the pole lug to be detected, and determine the first column coordinate of the pole lug to be detected according to the contour of the pole lug to be detected; Calculate and determine first upper intersection point coordinates and first lower intersection point coordinates according to the first row coordinates and the first column coordinates, and determine the area to be detected according to the first upper intersection point coordinates and the first lower intersection point coordinates; The calculation and determination of the first upper intersection point coordinates and the first lower intersection point coordinates according to the first row coordinates and the first column coordinates is specifically: Determine a first upper tangent circle and a second upper tangent circle according to the first row coordinate and the first column coordinate, determine that the flush side of the electrode piece to be detected is connected to the top side of the electrode tab to be detected through the first upper tangent circle, and determine that the top side of the electrode tab to be detected is connected to the oblique side through the second upper tangent circle; After determination, the intersection point of the second upper tangent circle and the hypotenuse of the pole ear to be detected is taken as the first upper intersection point, and the coordinates of the first upper intersection point are obtained; Determine a first undercut circle and a second undercut circle according to the first row coordinate and the first column coordinate, determine that the flush side of the electrode piece to be detected is connected to the bottom side of the electrode tab to be detected through the first undercut circle, and determine that the bottom side of the electrode tab to be detected is connected to the oblique side through the second undercut circle; After the determination, the second lower cutting circle and the hypotenuse of the pole ear to be detected are taken as the first lower intersection point, and the coordinates of the first lower intersection point are obtained.

2. A method for detecting a tab of a lithium battery pole piece according to claim 1, characterized in that: The fitting result is obtained by comparing and fitting the standard tab profile and the tab profile to be tested, specifically: Locate the top region of the pole lug to be detected, compare and fit the contour of the pole lug to be detected in the top region of the pole lug to be detected and the contour of the standard pole lug corresponding to the standard detection region, and obtain a fitting result of the top of the pole lug to be detected; Locating the middle region of the standard pole lug, comparing and fitting the pole lug contour in the middle region of the standard pole lug and the pole lug contour to be detected in the middle region of the pole lug to be detected, and obtaining a fitting result of the middle region of the pole lug to be detected; The standard tab bottom region is located, and the tab contour within the standard tab bottom region is compared and fitted with the tab contour to be detected within the corresponding tab bottom region to obtain a fitting result of the tab bottom to be detected.

3. A method for detecting a tab of a lithium battery pole piece according to claim 1, characterized in that: The step of determining the detection condition of the tab to be detected according to the fitting result, the area to be detected and the preset standard detection area is specifically as follows: Comparing the fitting result of the area to be detected with a first threshold interval preset for the corresponding detection area; wherein the first threshold interval includes an outward expansion threshold interval and an inward contraction threshold interval; If the fitting result is less than or equal to the first threshold interval of the corresponding detection area, the detection of the electrode tab to be detected passes; If one or more of the fitting results are greater than the first threshold interval of the corresponding detection area, the detection of the electrode tab to be detected fails.

4. A method for detecting a tab of a lithium battery pole piece as claimed in claim 3, characterized in that: If one or more of the fitting results are greater than the first threshold interval of the corresponding detection area, the detection of the tab to be detected fails, specifically including: If the fitting result is greater than the outer expansion threshold interval of the corresponding detection area, it is determined that the pole tab to be detected is a pole tab remnant and the pole tab to be detected fails the detection; If the fitting result is greater than the shrinkage threshold interval of the corresponding detection area, it is determined that the pole lug to be detected is damaged and the pole lug to be detected fails the detection; Among them, the outward expansion threshold interval is the basis for judging whether the pole tab is the pole tab remnant; the inward contraction threshold interval is the basis for judging whether the pole tab is the pole tab damaged.

5. A lithium battery pole piece lug detection system, characterized in that: The detection system includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor processes the computer program, it implements the method for detecting the tab of a lithium battery pole piece as described in any one of claims 1 to 4.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for detecting a tab of a lithium battery pole piece according to any one of claims 1 to 4 is executed.

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