Pole piece winding detection method, device and system

Abstract

The invention provides a pole piece winding detection method, device and system, and the method comprises the steps: obtaining the cathode image data of a target cathode piece; acquiring first anode image data of a first anode strip on a first side in the thickness direction of the target cathode strip; acquiring second anode image data of a second anode plate on a second side in the thickness direction of the target cathode plate; determining a width difference value of a first side according to the cathode image data and the first anode image data; and determining a width difference value of the second side according to the cathode image data and the second anode image data.

Description

Pole winding detection method, device and system Technical Field

[0001] The present application relates to the field of battery production technology, and more specifically, to a pole piece winding detection method, device and system. Background Art

[0002] Currently, one of the tests for wound electrodes is to detect the width difference (Overhang, abbreviated as: OH) value of the electrode from the anode to the cathode. However, there are some missed detections in the current OH value test, which may lead to the failure to detect lithium deposition on the edge of the electrode, and then lead to puncture of the diaphragm and overlap of the cathode electrode, or lithium dendrite growth and overlap of the electrode end face and the electrode ear, resulting in internal short thermal runaway.

[0003] Summary of the Invention

[0004] In view of this, the purpose of the embodiments of the present application is to provide a pole piece winding detection method, device and system to alleviate the current situation of missed detection in the OH value detection of wound pole pieces.

[0005] In a first aspect, an embodiment of the present application provides a pole piece winding detection method, comprising:

[0006] Acquiring cathode image data of a target cathode sheet;

[0007] Acquire first anode image data of a first anode sheet on a first side in a thickness direction of the target cathode sheet;

[0008] Acquire second anode image data of a second anode sheet on a second side in a thickness direction of the target cathode sheet;

[0009] determining a width difference of a first side according to the cathode image data and the first anode image data;

[0010] A width difference of the second side is determined according to the cathode image data and the second anode image data.

[0011] In the above embodiment, the OH value of both sides of the cathode electrode can be tested, so that the OH value detection can be more comprehensive, and the OH value of the electrode can be avoided from being missed, thereby reducing the situation where the edge of the anode electrode does not extend beyond the cathode electrode, which will cause lithium deposition on the edge electrode, and also reducing the situation where the diaphragm is pierced and the cathode electrode is overlapped, or lithium dendrites grow and overlap the electrode end face and the ear, causing internal short thermal runaway. Of course, by more comprehensive OH value detection of the electrode, the probability of unqualified batteries leaving the factory can also be reduced, thereby improving the quality of the batteries leaving the factory.

[0012] In an optional embodiment, the width difference of the first side includes: a first width difference of the non-tab side and a second width difference of the tab side;

[0013] The determining the width difference of the first side according to the cathode image data and the first anode image data includes:

[0014] Determining a first cathode edge line on a non-tab side and a second cathode edge line on a tab side of the target cathode sheet according to the cathode image data;

[0015] determining a first anode edge line on a non-tab side and a second anode edge line on a tab side of the first anode sheet based on the first anode image data;

[0016] determining the first width difference according to the first cathode edge line and the first anode edge line;

[0017] The second width difference is determined according to the second cathode edge line and the second anode edge line.

[0018] In an optional embodiment, the width difference of the second side includes: a third width difference on the non-tab side and a fourth width difference on the tab side;

[0019] The determining the width difference of the second side according to the cathode image data and the second anode image data includes:

[0020] determining a third width difference of the second side according to the cathode image data and the second anode image data;

[0021] A fourth width difference of the second side is determined according to the cathode image data, the first anode image data, and the second anode image data.

[0022] In the above embodiment, the determination of the width difference of the second side can be combined with the width difference of the first side, which can reduce the calibration requirements for the detection equipment and make the setting of the equipment environment for detecting the width difference simpler.

[0023] In an optional embodiment, determining the third width difference of the second side according to the cathode image data and the second anode image data includes:

[0024] determining a third cathode edge line of the target cathode piece on the non-tab side of the second side according to the cathode image data;

[0025] determining a third anode edge line on a non-tab side of the second anode sheet based on the second anode image data;

[0026] Determining a first distance based on the third cathode edge line and a preset reference line, wherein the preset reference line is a reference set by an image acquisition device used to capture an image of the target cathode sheet and the anode sheets on both sides thereof;

[0027] determining a second distance based on the third anode edge line and a preset reference line;

[0028] The third width difference is determined according to the first distance and the second distance.

[0029] In an optional embodiment, determining the fourth width difference of the second side according to the cathode image data, the first anode image data, and the second anode image data includes:

[0030] Determining a first glue coating width on the first side and a second glue coating width on the second side of the target cathode sheet according to the cathode image data;

[0031] The fourth width difference is calculated according to the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width, and the second glue coating width.

[0032] In the above embodiment, the fourth width difference of the second side can be calculated in combination with the width of the glue coating of the target cathode sheet, so that the fourth width difference of the second side can be determined without the need for other auxiliary lines, reducing the additional settings required for detecting the fourth width difference of the second side and improving the efficiency of the detection environment layout.

[0033] In an optional embodiment, the fourth width difference is calculated based on the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width and the second glue coating width, including: determining the first anode sheet difference based on the width of the second anode sheet and the width of the first anode sheet; determining the first glue coating difference based on the second glue coating width of the second side of the target cathode sheet and the first glue coating width of the first side of the target cathode sheet; and obtaining the fourth width difference by calculating the sum of the first anode sheet difference, the first glue coating difference and the second width difference of the tab side of the first side.

[0034] In an optional embodiment, the fourth width difference is determined by the following formula:

[0035] OH4=Aw2-Aw1+OH2-AT1+AT2;

[0036] Among them, OH4 represents the fourth width difference; Aw1 represents the width of the first anode sheet; Aw2 represents the width of the second anode sheet; OH2 represents the second width difference of the tab side of the first side; AT1 represents the first glue coating width of the first side of the target cathode sheet; AT2 represents the second glue coating width of the second side of the target cathode sheet.

[0037] In the above embodiment, the fourth width difference of the second side can be directly calculated by combining the relationship between the width differences of the two sides with a formula, which can improve calculation efficiency.

[0038] In an optional embodiment, determining the fourth width difference of the second side according to the cathode image data, the first anode image data, and the second anode image data includes:

[0039] determining a second glue coating width and a glue coating edge line of the second side according to the cathode image data;

[0040] determining a fourth anode edge line on the tab side of the second anode sheet according to the second anode image data;

[0041] A fourth width difference of the second side is calculated according to a preset reference line, the second glue coating width, the glue coating edge line, and the fourth anode edge line.

[0042] In an optional embodiment, the fourth width difference of the second side is calculated based on the preset baseline, the second glue coating width, the glue coating edge line and the fourth anode edge line, including: determining the distance between the preset baseline and the glue coating edge line; determining the distance between the preset baseline and the fourth anode edge line; determining the distance difference between the distance between the preset baseline and the glue coating edge line and the distance between the preset baseline and the fourth anode edge line; calculating the difference between the second glue coating width of the second side of the target cathode sheet and the distance difference to obtain the fourth width difference of the second side.

[0043] In an optional embodiment, the fourth width difference is determined by the following formula:

[0044] OH4=AT2-[(Bl-AT e )-(Bl-Ae4)];

[0045] Wherein, AT2 represents the second glue coating width of the second side of the target cathode sheet; Bl represents the preset reference line; AT e Ae4 represents the fourth anode edge line on the tab side of the second anode sheet;

[0046] Bl-AT erepresents the distance between the preset reference line and the glue coating edge line, and Bl-Ae4 represents the distance between the preset reference line and the fourth anode edge line.

[0047] In the above embodiment, the relationship between the width differences of the two sides can be combined to directly calculate the fourth width difference of the second side through a formula, which can improve calculation efficiency.

[0048] In an optional embodiment, determining the width difference of the second side according to the cathode image data and the second anode image data includes:

[0049] Determining the glue coating edge line of the target cathode sheet according to the cathode image data;

[0050] determining an anode edge line of the second anode sheet according to the second anode image data;

[0051] The width difference of the second side is determined according to the glue coating edge line and the anode edge line of the second anode sheet.

[0052] In an optional embodiment, determining the glue coating edge line of the target cathode sheet according to the cathode image data includes:

[0053] Determining the edge type of the glue coating of the target cathode sheet according to the pixel distribution in the cathode image data, wherein the edge type includes: wavy edge and gradient edge;

[0054] In the case where the edge type of the target cathode sheet is a wavy edge, a trough of the wavy edge is selected to determine the edge line of the target cathode sheet, wherein the trough of the wavy edge is a position on the wavy edge closest to the edge of the target cathode sheet where the glue is away from the film area;

[0055] When the edge type of the target cathode film is a gradient edge, the first target boundary line on the target cathode film is determined as the glue edge line of the target cathode film, wherein the difference between the first average grayscale of each pixel point in the film area divided by the first target boundary line and the second average grayscale of each pixel point in the glue area is greater than the first set threshold.

[0056] In the above embodiment, different methods of determining the gluing edge and gluing width can be used for gluing different virtual edges, so that the gluing edge and gluing width can be determined more accurately, and further, the accuracy of the width difference can be improved.

[0057] In an optional embodiment, determining the edge type of the glue coating of the target cathode sheet according to the pixel distribution in the cathode image data includes:

[0058] Performing edge grabbing processing from the edge of the target cathode sheet away from the film area toward the film area of ​​the target cathode sheet, and selecting a specified number of continuous pixel points in a first direction to calculate real-time grayscale values;

[0059] When the difference between the real-time grayscale value and the grayscale value of the pixel points at the glue coating edge of the target cathode sheet is greater than a second set threshold, the selected specified number of consecutive pixel points are determined to be part of the glue coating edge line, and the first direction is a direction parallel to the glue coating edge;

[0060] When the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue edge of the target cathode film is not greater than the second set threshold, the method is translated in a second direction perpendicular to the first direction to select a specified number of continuous pixel points again to calculate the real-time grayscale value until the glue edge line of the target cathode film is determined, and the glue edge type is determined according to the shape of the glue edge line.

[0061] In the above implementation, the glue coating edge is first captured by pixel comparison, and after the glue coating edge line is determined, the glue coating width is determined based on the glue coating edge line, so that the determined glue coating width can be more accurate and reliable.

[0062] In a second aspect, an embodiment of the present application provides a pole piece winding detection device, comprising:

[0063] A first acquisition module is used to acquire cathode image data of a target cathode sheet;

[0064] A second acquisition module is used to acquire first anode image data of a first anode sheet on a first side in a thickness direction of the target cathode sheet;

[0065] a third acquisition module, configured to acquire second anode image data of a second anode sheet on a second side in a thickness direction of the target cathode sheet;

[0066] a first determining module, configured to determine a width difference of a first side according to the cathode image data and the first anode image data;

[0067] The second determining module is configured to determine a width difference of the second side according to the cathode image data and the second anode image data.

[0068] In a third aspect, an embodiment of the present application provides a pole piece winding detection system, comprising:

[0069] a first acquisition device for acquiring image data of a first side of the pole piece;

[0070] a second acquisition device for acquiring image data of a second side of the pole piece;

[0071] The processing device is used to process the data collected by the collection device to execute the steps of the above-mentioned pole piece winding detection method.

[0072] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the following embodiments are given in conjunction with the accompanying drawings for detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0074] FIG1 is a cross-sectional schematic diagram of a wound pole piece provided in an embodiment of the present application;

[0075] FIG2 is a block diagram of a pole piece winding detection system provided in an embodiment of the present application;

[0076] FIG3 is a schematic diagram of an installation scenario of a collection device provided in an embodiment of the present application;

[0077] FIG4 is a flow chart of a pole piece winding detection method provided in an embodiment of the present application;

[0078] FIG5a is a schematic diagram of a first side of a target cathode sheet provided in an embodiment of the present application;

[0079] FIG5 b is a schematic diagram of the second side of the target cathode sheet provided in an embodiment of the present application;

[0080] FIG6 a is a schematic diagram of the stacking of a first side of a target cathode sheet and a first anode sheet in a thickness direction according to an embodiment of the present application;

[0081] FIG6 b is a schematic diagram of the stacking of the second side of the target cathode sheet in the thickness direction and the second anode sheet provided by an embodiment of the present application;

[0082] FIG6 c is a schematic diagram of the side surfaces of a target cathode sheet, a first anode sheet, and a second anode sheet provided in an embodiment of the present application;

[0083] FIG6 d is a schematic diagram of the side surfaces of the target cathode sheet and the second anode sheet provided in an embodiment of the present application;

[0084] FIG7 is an optional flow chart of step 250 of the pole piece winding detection method provided in an embodiment of the present application;

[0085] FIG8 is an optional flow chart of step 250 of the pole piece winding detection method provided in an embodiment of the present application;

[0086] FIG9 a shows a schematic diagram of a cathode electrode with a wavy edge;

[0087] FIG9 b shows a schematic diagram of a cathode electrode with a gradient edge type;

[0088] FIG10 is a schematic diagram of the functional modules of the pole piece winding detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0089] It is necessary to describe the technical solutions in the embodiments of the present application in combination with the drawings in the embodiments of the present application.

[0090] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0091] In the production process of lithium batteries, one of the links is the lithium battery winding process. In order to ensure that the batteries leaving the factory can better meet the battery production standards, the OH value of the anode and cathode needs to be monitored during the winding process of the battery cell to prevent defective batteries from leaving the factory.

[0092] As shown in FIG1 , the winding process can be to wind the electrode into a ring, and each circle can be determined as two folds, wherein, if the production of lithium batteries requires winding M circles of electrode, 2M folded anodes (including the 1st to 2Mth folded anodes, respectively) and 2M folded cathodes (including the 1st to 2Mth folded cathodes, respectively) can be formed. In the example shown in FIG1 , the solid line can represent the anode winding truncation diagram, and the dotted line can represent the cathode winding truncation diagram. Only a schematic diagram of the winding effect of some electrode sheets is shown, wherein FIG1 shows a 7-fold anode (respectively marked as A1, A2, ..., A7 in the figure), and a 5-fold cathode (respectively marked as C1, C2, ..., C5 in the figure). The current detection of the winding process is to detect the OH value from the Nth folded cathode to the N+2th folded anode, and the OH value from the Nth folded cathode to the Nth anode is not detected. If the edge of the anode electrode of the wound battery cell does not extend beyond the cathode electrode on one side, lithium will be deposited on the edge electrode, which will then pierce the diaphragm and overlap the cathode electrode, or lithium dendrites will grow and overlap the electrode end face and the electrode ear, causing internal short thermal runaway.

[0093] Based on the analysis of the current situation by the inventor of this application, this application provides a pole piece winding detection method, device and system, which can detect the OH value of both sides of the pole piece, reduce the lithium plating on the edge of the pole piece, and then pierce the diaphragm and overlap the cathode pole piece, or lithium dendrites grow and overlap the pole piece end face and the pole ear, resulting in internal short thermal runaway.

[0094] The electrode winding detection system provided in the embodiment of the present application can be installed around the winding equipment in the electrode winding stage of the battery cell in a battery manufacturing plant, and is used to collect image data of the cathode and anode of the electrode during the winding process.

[0095] An embodiment of the present application provides a pole piece winding detection system. As shown in FIG2 , the pole piece winding detection system 100 may include: a collection device 110 and a processing device 120 .

[0096] Exemplarily, the pole piece winding detection system may include a plurality of acquisition devices, which may be arranged at different positions to acquire image data of the pole piece at different positions and orientations during the winding process.

[0097] In this embodiment, the pole piece winding detection system may include: a first acquisition device 111 for acquiring image data of a first side of the pole piece, and a second acquisition device 112 for acquiring image data of a second side of the pole piece.

[0098] Depending on the arrangement of winding equipment during the electrode sheet winding stage of a battery cell in an actual battery manufacturing plant, the positions of the first acquisition device 111 and the second acquisition device 112 may also vary. It is understood that, in its installed position, the first acquisition device 111 can capture image data of the first side of the electrode sheet, and the second acquisition device 112 can capture image data of the second side of the electrode sheet.

[0099] As shown in Figure 3, an exemplary collection equipment installation scenario is shown. The figure shows four collection devices, including a first collection device 111 and a second collection device 112. Also included is a collection device 110 positioned around a winding needle. The wound electrode sheet can be sequentially wound around a roller 130 and then around a winding needle 140. Of course, Figure 3 is merely an example; the winding stage in an actual battery manufacturing plant may include more equipment than shown in the example in Figure 3.

[0100] For example, the acquisition device 110 may be a CCD (charge coupled device) camera. Of course, the acquisition device 110 may also be other cameras capable of acquiring images.

[0101] The processing device 120 is used to process the data collected by the collection device 110 to execute the various steps of the pole piece winding detection method provided in the embodiment of the present application.

[0102] Exemplarily, the processing device 120 may be integrated with the acquisition device 110 . The integrated device may be used to acquire image data of the electrode and may also be used to process the acquired data.

[0103] The processing device 120 may also be a host computer or other device that is communicatively connected to the acquisition device 110. The processing device 120 may include a processor. The processor may be an integrated circuit chip having signal processing capabilities. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component. The various methods, steps and logic block diagrams disclosed in the embodiments of the present application may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0104] The pole piece winding detection system in this embodiment can be used to execute each step in each method provided in the embodiments of the present application. The following describes in detail the implementation process of the pole piece winding detection method through several embodiments.

[0105] Please refer to Figure 4, which is a flow chart of a pole piece winding detection method provided in an embodiment of the present application. Each step in the method of this embodiment can be performed by a processing device. The specific process shown in Figure 4 will be described in detail below.

[0106] Step 210: Acquire cathode image data of the target cathode sheet.

[0107] Illustratively, the cathode image data may include image data of a first side of the target cathode sheet and image data of a second side of the target cathode sheet.

[0108] The cathode image data of the target cathode sheet can be acquired by various acquisition devices installed in a winding stage of a battery manufacturing plant.

[0109] The image data of the first side may include a film area and a glue coating (AT11) area, and the image data of the second side may also include a film area and a glue coating area.

[0110] In one example, as shown in Figures 5a and 5b, schematic diagrams of the first side and the second side of the target cathode sheet are shown. The image data of the first side of the target cathode sheet may include the cathode tab Cl, the adhesive coating AT1 on the first side, and the cathode film area Ma1 on the first side. The image data of the first side of the target cathode sheet may include the cathode tab Cl, the adhesive coating AT2 on the second side, and the cathode film area Ma2 on the second side. The width of the adhesive coating AT1 on the first side may be the same as or different from the width of the adhesive coating AT2 on the second side. In the examples shown in Figures 5a and 5b, the width of the adhesive coating AT1 on the first side is different from the width of the adhesive coating AT2 on the second side.

[0111] Step 220 : Acquire first anode image data of a first anode sheet on a first side in a thickness direction of the target cathode sheet.

[0112] The first anode sheet may be disposed on a first side of the target cathode sheet. After winding, the first anode sheet is located on the first side of the target cathode sheet.

[0113] The cathode image data of the target cathode sheet can be acquired by various acquisition devices installed in the winding stage of the battery manufacturing plant. In the example shown in FIG3 , the first anode image data of the first anode sheet can be acquired by the first acquisition device 111 .

[0114] Taking the example shown in FIG. 1 as an example, the target cathode sheet is the third folded cathode C3 , and the first anode sheet may be the fifth folded anode A5 .

[0115] Step 230 : Acquire second anode image data of a second anode sheet on a second side in the thickness direction of the target cathode sheet.

[0116] The second anode sheet may be disposed on the second side of the target cathode sheet. After winding, the second anode sheet is located on the second side of the target cathode sheet.

[0117] The cathode image data of the target cathode sheet can be acquired by various acquisition devices installed in the winding stage of the battery manufacturing plant. In the example shown in FIG3 , the second anode image data of the second anode sheet can be acquired by the second acquisition device 112 .

[0118] Taking the example shown in FIG. 1 as an example, the target cathode sheet is the third folded cathode C3 , and the second anode sheet may be the third folded anode A3 .

[0119] Step 240 : Determine a width difference of the first side according to the cathode image data and the first anode image data.

[0120] The width difference of the first side may be determined using the image data of the first side included in the cathode image data and the first anode image data.

[0121] For example, the width difference of the first side may be expressed as the distance between an edge of the film area of ​​the first side of the target cathode sheet and an edge of the film area of ​​the first anode sheet.

[0122] Optionally, the width difference of the first side may include a width difference of the tab side and a width difference of the non-tab side. The width difference of the tab side of the first side may represent the distance between the edge of the tab side of the first side of the target cathode sheet and the edge of the membrane area of ​​the first anode sheet on the tab side; and the width difference of the non-tab side of the first side may represent the distance between the edge of the non-tab side of the first side of the target cathode sheet and the edge of the membrane area of ​​the first anode sheet on the non-tab side.

[0123] Step 250 : Determine a width difference of the second side according to the cathode image data and the second anode image data.

[0124] For example, the width difference of the second side may be expressed as the distance between the edge of the film area on the second side of the target cathode sheet and the edge of the film area of ​​the second anode sheet.

[0125] Optionally, the width difference of the second side may include a width difference of the tab side and a width difference of the non-tab side. The width difference of the tab side of the second side may represent the distance between the edge of the tab side of the second side of the target cathode sheet and the edge of the membrane area of ​​the second anode sheet on the tab side; and the width difference of the non-tab side of the second side may represent the distance between the edge of the non-tab side of the second side of the target cathode sheet and the edge of the membrane area of ​​the second anode sheet on the non-tab side.

[0126] The above method can detect the OH value of both sides of the cathode electrode, making the OH value detection more comprehensive and avoiding missing the OH value of the electrode. Of course, by more comprehensive OH value detection of the electrode, the probability of unqualified batteries leaving the factory can also be reduced, thereby improving the quality of the batteries leaving the factory.

[0127] Regarding the width difference of the first side of the target cathode piece, the positions of the anode edge line and the cathode edge can be determined based on the image positioning of the acquisition device, and then based on the width difference between the anode edge line and the cathode edge from the first side of the target cathode piece.

[0128] Exemplarily, the width difference on the first side includes: a first width difference on the non-tab side and a second width difference on the tab side. In the example shown in FIG6 a , the first width difference on the non-tab side is denoted as OH1 , and the second width difference on the tab side is OH2 .

[0129] The above-mentioned step 340 may include: determining the first cathode edge line on the non-pole tab side and the second cathode edge line on the pole tab side of the target cathode sheet based on the cathode image data; determining the first anode edge line on the non-pole tab side and the second anode edge line on the pole tab side of the first anode sheet based on the first anode image data; determining the first width difference based on the first cathode edge line and the first anode edge line; and determining the second width difference based on the second cathode edge line and the second anode edge line.

[0130] In the example shown in Figure 6a, it shows the first anode edge line Ae1 on the non-tab side of the first anode sheet, the second anode edge line Ae2 on the tab side, the first cathode edge line Ce1 on the non-tab side of the target cathode sheet, the second cathode edge line Ce2 on the tab side, and the membrane area Ma3 of the first anode sheet.

[0131] Exemplarily, the cathode image data may include the first cathode edge line Ce1 on the non-pole tab side and the second cathode edge line Ce2 on the pole tab side of the target cathode sheet. By edge recognition of the image, the positions of the first cathode edge line Ce1 and the second cathode edge line Ce2 in the image data are identified.

[0132] Exemplarily, the first anode image data may include a first anode edge line Ae1 on the non-pole tab side and a second anode edge line Ae2 on the pole tab side, and the positions of the first anode edge line Ae1 and the second anode edge line Ae2 in the first anode image data are identified in the image data by edge recognition of the image.

[0133] Therefore, a first width difference can be determined according to the positions of the first cathode edge line Ce1 and the first anode edge line Ae1, and a second width difference can be determined according to the positions of the second anode edge line Ae2 and the second anode edge line Ae2.

[0134] Optionally, the acquisition device for collecting cathode image data and first anode image data can be calibrated with a binocular camera in advance. Therefore, the three-dimensional coordinates of the first cathode edge line Ce1 and the second cathode edge line Ce2 in the cathode image data can be determined, and the three-dimensional coordinates of the first anode edge line Ae1 and the second anode edge line Ae2 in the first anode image data can also be determined. Therefore, based on the three-dimensional coordinates of the first cathode edge line Ce1 and the three-dimensional coordinates of the first anode edge line Ae1, the distance between the first cathode edge line Ce1 and the first anode edge line Ae1 can be calculated to obtain a first width difference. The distance between the second cathode edge line Ce2 and the second anode edge line Ae2 can also be calculated based on the three-dimensional coordinates of the second cathode edge line Ce2 and the three-dimensional coordinates of the second anode edge line Ae2 to obtain a second width difference.

[0135] Optionally, the equipment used to collect the cathode image data and the first anode image data may be pre-calibrated for the baseline. The distances between the first cathode edge line Ce1 and the second cathode edge line Ce2 and the baseline may be determined, as may the distances between the first anode edge line Ae1 and the second anode edge line Ae2 and the baseline.

[0136] Taking the example shown in FIG6a as an example, the first width difference can be calculated using the following formula:

[0137] OH1=(Bl-Ae1)-(Bl-Ce1);

[0138] Wherein, OH1 represents the first width difference; Bl represents the preset reference line; (Bl-Ae1) represents the distance between the preset reference line and the first anode edge line; (Bl-Ce1) represents the distance between the preset reference line and the first cathode edge line.

[0139] Taking the example shown in FIG6a as an example, the second width difference can be calculated using the following formula:

[0140] OH2=(Bl-Ce2)-(Bl-Ae2);

[0141] Wherein, OH2 represents the second width difference; Bl represents the preset reference line; (Bl-Ae2) represents the distance between the preset reference line and the second anode edge line; (Bl-Ce2) represents the distance between the preset reference line and the second cathode edge line.

[0142] In another example, as shown in FIG6c , FIG6c shows the target cathode sheet C, the first anode sheet A1, the second anode sheet A2, the width Aw1 of the first anode sheet, the width Aw2 of the second anode sheet, and the width Cw of the target cathode sheet. In this example, the second width difference can be calculated using the following formula:

[0143] OH2=Aw1-(Cw-AT1);

[0144] Wherein, OH2 represents the second width difference; Aw1 represents the width of the first anode sheet in the diagram; Cw represents the width of the target cathode sheet in the diagram; AT1 represents the glue coating width of the target cathode sheet on the first side.

[0145] In order to reduce the equipment changes in the original winding stage, when determining the width difference of the second side, the relevant data of the first side and the relationship between the width difference of the first side and the width difference of the second side can also be combined to determine the width difference of the second side.

[0146] Exemplarily, the width difference of the second side includes: a third width difference on the non-tab side and a fourth width difference on the tab side. In the example shown in FIG6 b , the third width difference on the non-tab side is denoted as OH3 , and the fourth width difference on the tab side is OH4 .

[0147] As shown in FIG. 7 , step 250 may include step 251 and step 252 .

[0148] Step 251 : Determine a third width difference of the second side according to the cathode image data and the second anode image data.

[0149] Optionally, step 251 may include: determining the third cathode edge line of the target cathode sheet on the non-pole ear side of the second side based on the cathode image data; determining the third anode edge line on the non-pole ear side of the second anode sheet based on the second anode image data; determining the first distance based on the third cathode edge line and a preset baseline; determining the second distance based on the third anode edge line and the preset baseline; and determining the third width difference based on the first distance and the second distance.

[0150] Taking the example shown in Figure 6b as an example, it shows the third anode edge line Ae3 on the non-tab side of the second anode sheet, the fourth anode edge line Ae4 on the tab side, the third cathode edge line Ce3 on the non-tab side of the target cathode sheet, the fourth cathode edge line Ce4 on the tab side, and the membrane area Ma4 of the second anode sheet.

[0151] The preset reference line is a reference set by an image acquisition device used to acquire images of the target cathode sheet and the anode sheets on both sides thereof. For example, the preset reference line can be calibrated for the same position by each acquisition device.

[0152] In one embodiment, the third width difference may be calculated using the following formula:

[0153] OH3=(Bl-Ae3)-(Bl-Ce3);

[0154] Wherein, OH3 represents the third width difference; Bl represents the preset reference line; (Bl-Ae3) represents the distance between the preset reference line and the third anode edge line; (Bl-Ce3) represents the distance between the preset reference line and the third cathode edge line.

[0155] Step 252 : Determine a fourth width difference of the second side according to the cathode image data, the first anode image data, and the second anode image data.

[0156] In one embodiment, the first glue coating width of the target cathode sheet on the first side and the second glue coating width on the second side can be determined based on the cathode image data; and the fourth width difference can be calculated based on the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width and the second glue coating width.

[0157] Referring again to FIG. 6 c , the fourth width difference can be calculated using the following formula:

[0158] OH4=Aw2-(Cw-AT2);

[0159] Wherein, OH4 represents the fourth width difference; Aw2 represents the width of the second anode sheet in the diagram; Cw represents the width of the target cathode sheet in the diagram; and AT2 represents the glue coating width of the target cathode sheet on the second side.

[0160] Exemplarily, the above-mentioned calculation of the fourth width difference based on the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width and the second glue coating width may include: determining the first anode sheet difference based on the width of the second anode sheet and the width of the first anode sheet; determining the first glue coating difference based on the second glue coating width of the second side of the target cathode sheet and the first glue coating width of the first side of the target cathode sheet; and calculating the sum based on the first anode sheet difference, the first glue coating difference and the second width difference of the tab side of the first side to obtain the fourth width difference.

[0161] Based on the formulas of the third width difference and the fourth width difference obtained in the example shown in FIG6c , it can be determined that the fourth width difference is determined by the following formula:

[0162] OH4=Aw2-Aw1+OH2-AT1+AT2;

[0163] Among them, OH4 represents the fourth width difference; Aw1 represents the width of the first anode sheet; Aw2 represents the width of the second anode sheet; OH2 represents the second width difference of the tab side of the first side; AT1 represents the first glue coating width of the first side of the target cathode sheet; AT2 represents the second glue coating width of the second side of the target cathode sheet.

[0164] In this embodiment, the width of the first anode sheet represented by Aw1 can be understood as the width of the portion shown in the image, and the width of the second anode sheet represented by Aw2 can be understood as the width of the portion shown in the image.

[0165] In another embodiment, the second glue coating width and the glue coating edge line of the second side are determined based on the cathode image data; the fourth anode edge line on the pole ear side of the second anode sheet is determined based on the second anode image data; and the fourth width difference of the second side is calculated based on the preset baseline, the second glue coating width, the glue coating edge line and the fourth anode edge line.

[0166] Exemplarily, the above-mentioned calculation of the fourth width difference of the second side based on the preset baseline, the second glue coating width, the glue coating edge line and the fourth anode edge line may include: determining the distance between the preset baseline and the glue coating edge line; determining the distance between the preset baseline and the fourth anode edge line; determining the distance difference between the distance between the preset baseline and the glue coating edge line and the distance between the preset baseline and the fourth anode edge line; calculating the difference between the second glue coating width of the second side of the target cathode sheet and the distance difference to obtain the fourth width difference of the second side.

[0167] Exemplarily, as shown in FIG6d , the fourth width difference is determined by the following formula:

[0168] OH4=AT2-[(Bl-AT e )-(Bl-Ae4)];

[0169] Wherein, AT2 represents the second glue coating width of the second side of the target cathode sheet; Bl represents the preset reference line; AT e Ae4 represents the fourth anode edge line on the tab side of the second anode sheet;

[0170] Bl-AT e represents the distance between the preset reference line and the glue coating edge line, and Bl-Ae4 represents the distance between the preset reference line and the fourth anode edge line.

[0171] Based on the above steps, the calculation of each width difference can be achieved. However, accurate calculation of the width difference is based on accurate determination of each edge line. Therefore, in order to improve the accuracy of the width difference, the edge lines are further determined in some ways below.

[0172] As shown in FIG. 8 , the above-mentioned step 250 may include steps 253 to 255 .

[0173] Step 253: Determine the glue coating edge line of the target cathode sheet according to the cathode image data.

[0174] Step 254 : determining the anode edge line of the second anode sheet based on the second anode image data.

[0175] Step 255 : determining a width difference of the second side according to the glue coating edge line and the anode edge line of the second anode sheet.

[0176] Due to process reasons, the edge of the glue coating may not form a straight line and may appear as a virtual edge. Therefore, the above step 253 may include: determining the edge type of the glue coating of the target cathode sheet based on the pixel distribution in the cathode image data.

[0177] The edge types include irregular edges such as wavy edges, gradient edges, and white edges.

[0178] In the case that the glue-coated edge type of the target cathode sheet is a wavy edge, the trough of the wavy edge is selected to determine the glue-coated edge line of the target cathode sheet.

[0179] The trough of the wave edge is the position on the wave edge closest to the edge of the target cathode sheet where the glue is away from the film area.

[0180] As shown in Figure 9a, which shows a schematic diagram of a cathode electrode with a wavy edge, the line Ce2 in the figure can be used as the second cathode edge line.

[0181] Of course, depending on actual needs, if the target cathode sheet has a wavy edge, the crest of the wavy edge can be selected to determine the target cathode sheet's gluing edge line. Alternatively, a position between the trough and the crest of the wavy edge can be selected to determine the target cathode sheet's gluing edge line.

[0182] In a case where the glue-coated edge type of the target cathode sheet is a gradient edge, a first target boundary line on the target cathode sheet is determined as the glue-coated edge line of the target cathode sheet.

[0183] The difference between a first average grayscale of each pixel point in the film area divided by the first target boundary line and a second average grayscale of each pixel point in the glue coating area is greater than a first set threshold.

[0184] The first set threshold value can be set as needed. For example, the first set threshold value can be a value between 60 and 80. For example, the first set threshold value can be 60, 80, 70, 75, 65, etc.

[0185] As shown in Figure 9b, a schematic diagram of a cathode electrode with a gradient edge is shown in Figure 9b. Line Ce2 in the figure can be used as the second cathode edge line.

[0186] In a case where the glue-coated edge type of the target cathode piece is a white shallow edge, a second target boundary line on the target cathode piece is determined as the glue-coated edge line of the target cathode piece.

[0187] The difference between the third average grayscale of each pixel point in the film area divided by the second target boundary line and the fourth average grayscale of each pixel point in the glue coating area is greater than the third set threshold.

[0188] Exemplarily, the third set threshold value may be equal to the first set threshold value. Of course, the third set threshold value may also be different from the first set threshold value.

[0189] The above-mentioned determination of the edge type of the target cathode film's glue coating based on the pixel distribution in the cathode image data may include: performing edge grabbing processing from the edge of the target cathode film's glue coating away from the film area toward the film area of ​​the target cathode film, and selecting a specified number of continuous pixel points in the first direction to calculate the real-time grayscale value.

[0190] Exemplarily, the edge of the target cathode sheet can be grasped along the edge of the glue coating away from the film area toward the film area of ​​the target cathode sheet. Taking Figure 9a as an example, pixel points can be selected along the second direction d2 to calculate the grayscale value.

[0191] The specified quantity is a quantity set according to actual needs. For example, the specified quantity can be 10, 20, 15, etc.

[0192] The real-time grayscale value calculated for a specified number of continuous pixel points may be an average value of the specified number of continuous pixel points.

[0193] When the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue edge of the target cathode film is greater than the second set threshold, the selected specified number of continuous pixel points are determined to be part of the glue edge line, and the first direction is the direction parallel to the glue edge.

[0194] Exemplarily, a specified number of continuous pixel points are selected in the first direction as a small area. When the difference between the real-time grayscale value of the small area and the grayscale value of the pixel points at the edge of the glue coating is greater than the second set threshold, the pixel points in the small area can be used as the wave edge capture line.

[0195] When the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue-coated edge of the target cathode film is greater than the second set threshold, it can be translated in the first direction to select a specified number of continuous pixel points for calculating the real-time grayscale value.

[0196] When the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue edge of the target cathode film is not greater than the second set threshold, the method is translated in a second direction perpendicular to the first direction to select a specified number of continuous pixel points again to calculate the real-time grayscale value until the glue edge line of the target cathode film is determined, and the glue edge type is determined according to the shape of the glue edge line.

[0197] Repeat the above steps until the glue coating edge line is selected. Further, the edge type can be determined according to the direction of the glue coating edge line.

[0198] Through the method in the embodiment of the present application, the OH values ​​of both sides of the cathode can be tested, and the arrangement of the pole pieces can be understood more comprehensively, thereby improving the accuracy and reliability of the detection of the battery cell during the manufacturing process. Furthermore, when determining the OH value, the method of determining the glue coating edge line can be improved, and the determined glue coating edge line can be made more accurate, thereby further improving the accuracy of the OH value.

[0199] Based on the same application concept, the embodiment of the present application also provides a pole piece winding detection device corresponding to the pole piece winding detection method. Since the principle of solving the problem by the device in the embodiment of the present application is similar to the aforementioned pole piece winding detection method embodiment, the implementation of the device in this embodiment can refer to the description in the embodiment of the above method, and the repeated parts will not be repeated.

[0200] Please refer to Figure 10, which is a schematic diagram of the functional modules of the electrode winding detection device provided in an embodiment of the present application. The various modules in the electrode winding detection device in this embodiment are used to perform the various steps in the above-mentioned method embodiment. The electrode winding detection device includes: a first acquisition module 310, a second acquisition module 320, a third acquisition module 330, a first determination module 340, and a second determination module 350; the contents of each module are as follows:

[0201] A first acquisition module 310 is used to acquire cathode image data of a target cathode sheet;

[0202] The second acquisition module 320 is configured to acquire first anode image data of a first anode sheet on a first side in a thickness direction of the target cathode sheet;

[0203] A third acquisition module 330 is configured to acquire second anode image data of a second anode sheet on a second side in the thickness direction of the target cathode sheet;

[0204] A first determining module 340 is configured to determine a width difference of a first side according to the cathode image data and the first anode image data;

[0205] The second determining module 350 is configured to determine a width difference of the second side according to the cathode image data and the second anode image data.

[0206] In a possible implementation manner, the width difference on the first side includes: a first width difference on the non-tab side and a second width difference on the tab side;

[0207] The first determination module 340 is used to determine the first cathode edge line on the non-pole tab side and the second cathode edge line on the pole tab side of the target cathode sheet based on the cathode image data; determine the first anode edge line on the non-pole tab side and the second anode edge line on the pole tab side of the first anode sheet based on the first anode image data; determine the first width difference based on the first cathode edge line and the first anode edge line; and determine the second width difference based on the second cathode edge line and the second anode edge line.

[0208] In a possible implementation manner, the width difference of the second side includes: a third width difference on the non-tab side and a fourth width difference on the tab side;

[0209] The second determining module 350 includes: a first difference calculating unit and a second difference calculating unit;

[0210] a first difference calculation unit, configured to determine a third width difference of the second side according to the cathode image data and the second anode image data;

[0211] The second difference calculation unit is configured to determine a fourth width difference of the second side according to the cathode image data, the first anode image data, and the second anode image data.

[0212] In one possible implementation, the first difference calculation unit is configured to:

[0213] Determining a third cathode edge line of the target cathode piece on the non-tab side of the second side according to the cathode image data;

[0214] Determining a third anode edge line on the non-tab side of the second anode sheet based on the second anode image data;

[0215] Determining a first distance based on the third cathode edge line and a preset reference line, wherein the preset reference line is a reference set by an image acquisition device used to capture an image of the target cathode sheet and the anode sheets on both sides thereof;

[0216] determining a second distance based on the third anode edge line and a preset reference line;

[0217] The third width difference is determined according to the first distance and the second distance.

[0218] In one possible embodiment, the second difference calculation unit is used to determine the first glue coating width of the target cathode film on the first side and the second glue coating width on the second side based on the cathode image data; and calculate the fourth width difference based on the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width and the second glue coating width.

[0219] In one possible embodiment, the second difference calculation unit is used to determine the first anode sheet difference based on the width of the second anode sheet and the width of the first anode sheet; determine the first glue coating difference based on the second glue coating width of the second side of the target cathode sheet and the first glue coating width of the first side of the target cathode sheet; and obtain the fourth width difference based on the sum of the first anode sheet difference, the first glue coating difference and the second width difference on the tab side of the first side.

[0220] In a possible implementation, the fourth width difference is determined by the following formula:

[0221] OH4=Aw2-Aw1+OH2-AT1+AT2;

[0222] Among them, OH4 represents the fourth width difference; Aw1 represents the width of the first anode sheet; Aw2 represents the width of the second anode sheet; OH2 represents the second width difference of the tab side of the first side; AT1 represents the first glue coating width of the first side of the target cathode sheet; AT2 represents the second glue coating width of the second side of the target cathode sheet.

[0223] In one possible implementation, the second difference calculation unit is configured to:

[0224] Determining a second glue coating width and a glue coating edge line of the second side according to the cathode image data;

[0225] determining a fourth anode edge line on the tab side of the second anode sheet according to the second anode image data;

[0226] A fourth width difference of the second side is calculated according to a preset reference line, the second glue coating width, the glue coating edge line, and the fourth anode edge line.

[0227] In one possible embodiment, the second difference calculation unit is used to determine the distance between the preset baseline and the glue edge line; determine the distance between the preset baseline and the fourth anode edge line; determine the distance difference between the distance between the preset baseline and the glue edge line and the distance between the preset baseline and the fourth anode edge line; calculate the difference between the second glue width of the second side of the target cathode sheet and the distance difference to obtain the fourth width difference of the second side.

[0228] In a possible implementation, the fourth width difference is determined by the following formula:

[0229] OH4=AT2-[(Bl-AT e )-(Bl-Ae4)];

[0230] Wherein, AT2 represents the second glue coating width of the second side of the target cathode sheet; Bl represents the preset reference line; AT e Ae4 represents the fourth anode edge line on the tab side of the second anode sheet;

[0231] Bl-AT e represents the distance between the preset reference line and the glue coating edge line, and Bl-Ae4 represents the distance between the preset reference line and the fourth anode edge line.

[0232] In one possible implementation, the second determination module 350 is used to determine the glue edge line of the target cathode sheet based on the cathode image data; determine the anode edge line of the second anode sheet based on the second anode image data; and determine the width difference of the second side based on the glue edge line and the anode edge line of the second anode sheet.

[0233] In one possible embodiment, the second determination module 350 is also used to determine the edge type of the target cathode film's glue coating based on the pixel distribution in the cathode image data, wherein the edge type includes: wavy edge and gradient edge; when the edge type of the target cathode film's glue coating is a wavy edge, the trough of the wavy edge is selected to determine the glue coating edge line of the target cathode film, wherein the trough of the wavy edge is the position on the wavy edge closest to the edge of the target cathode film's glue coating away from the membrane area; when the edge type of the target cathode film's glue coating is a gradient edge, the first target boundary line on the target cathode film is determined as the glue coating edge line of the target cathode film, wherein the difference between the first average grayscale of each pixel point in the membrane area divided by the first target boundary line and the second average grayscale of each pixel point in the glue coating area is greater than a first set threshold.

[0234] In one possible embodiment, the second determination module 350 is used to perform edge grabbing processing from the edge of the target cathode film away from the film area toward the film area of ​​the target cathode film, and select a specified number of continuous pixel points in a first direction to calculate the real-time grayscale value; when the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue edge of the target cathode film is greater than a second set threshold, the selected specified number of continuous pixel points are determined to be part of the glue edge line, and the first direction is a direction parallel to the glue edge.

[0235] When the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue edge of the target cathode film is not greater than the second set threshold, the method is translated in a second direction perpendicular to the first direction to select a specified number of continuous pixel points again to calculate the real-time grayscale value until the glue edge line of the target cathode film is determined, and the glue edge type is determined according to the shape of the glue edge line.

[0236] In addition, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the pole piece winding detection method described in the above method embodiment are executed.

[0237] The computer program product of the pole piece winding detection method provided in the embodiment of the present application includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the steps of the pole piece winding detection method described in the above method embodiment. For details, please refer to the above method embodiment, which will not be repeated here.

[0238] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to the multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0239] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0240] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk. It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0241] The foregoing description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0242] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A pole piece detection method, characterized in that: include: Acquiring cathode image data of a target cathode sheet; Acquire first anode image data of a first anode sheet on a first side in a thickness direction of the target cathode sheet; Acquire second anode image data of a second anode sheet on a second side in a thickness direction of the target cathode sheet; determining a width difference of a first side according to the cathode image data and the first anode image data; A width difference of the second side is determined according to the cathode image data and the second anode image data.

2. The method according to claim 1, characterized in that The width difference of the first side includes: a first width difference of the non-tab side and a second width difference of the tab side; The determining the width difference of the first side according to the cathode image data and the first anode image data includes: Determining a first cathode edge line on a non-tab side and a second cathode edge line on a tab side of the target cathode sheet according to the cathode image data; determining a first anode edge line on a non-tab side and a second anode edge line on a tab side of the first anode sheet based on the first anode image data; determining the first width difference according to the first cathode edge line and the first anode edge line; The second width difference is determined according to the second cathode edge line and the second anode edge line.

3. The method according to claim 1, characterized in that The width difference of the second side includes: a third width difference on the non-tab side and a fourth width difference on the tab side; The determining the width difference of the second side according to the cathode image data and the second anode image data includes: determining a third width difference of the second side according to the cathode image data and the second anode image data; A fourth width difference of the second side is determined according to the cathode image data, the first anode image data, and the second anode image data.

4. The method according to claim 3, characterized in that The determining, based on the cathode image data and the second anode image data, a third width difference of the second side includes: determining a third cathode edge line of the target cathode piece on the non-tab side of the second side according to the cathode image data; determining a third anode edge line on a non-tab side of the second anode sheet based on the second anode image data; Determining a first distance based on the third cathode edge line and a preset reference line, wherein the preset reference line is a reference set by an image acquisition device used to capture an image of the target cathode sheet and the anode sheets on both sides thereof; determining a second distance based on the third anode edge line and a preset reference line; The third width difference is determined according to the first distance and the second distance.

5. The method according to claim 3, characterized in that The determining of the fourth width difference of the second side according to the cathode image data, the first anode image data, and the second anode image data includes: Determining a first glue coating width on the first side and a second glue coating width on the second side of the target cathode sheet according to the cathode image data; The fourth width difference is calculated according to the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width, and the second glue coating width.

6. The method according to claim 5, characterized in that The calculating the fourth width difference according to the first anode image data, the second anode image data, the width difference of the first side, the first glue coating width, and the second glue coating width includes: determining a first anode sheet difference according to a width of the second anode sheet and a width of the first anode sheet; determining a first glue coating difference according to a second glue coating width on the second side of the target cathode sheet and a first glue coating width on the first side of the target cathode sheet; The fourth width difference is obtained by calculating and adding the first anode sheet difference, the first glue coating difference, and the second width difference on the tab side of the first side.

7. The method according to claim 3, characterized in that The determining of the fourth width difference of the second side according to the cathode image data, the first anode image data, and the second anode image data includes: determining a second glue coating width and a glue coating edge line of the second side according to the cathode image data; determining a fourth anode edge line on the tab side of the second anode sheet according to the second anode image data; A fourth width difference of the second side is calculated according to a preset reference line, the second glue coating width, the glue coating edge line, and the fourth anode edge line.

8. The method according to claim 7, characterized in that Calculating the fourth width difference of the second side according to the preset reference line, the second glue coating width, the glue coating edge line, and the fourth anode edge line includes: Determining the distance between the preset reference line and the glue coating edge line; Determining the distance between the preset reference line and the fourth anode edge line; Determining a distance difference between the distance between the preset reference line and the glue coating edge line and the distance between the preset reference line and the fourth anode edge line; A difference between a second glue coating width on the second side of the target cathode sheet and the distance difference is calculated to obtain a fourth width difference on the second side.

9. The method according to any one of claims 1 to 8, characterized in that The determining the width difference of the second side according to the cathode image data and the second anode image data includes: Determining the glue coating edge line of the target cathode sheet according to the cathode image data; determining an anode edge line of the second anode sheet according to the second anode image data; The width difference of the second side is determined according to the glue coating edge line and the anode edge line of the second anode sheet.

10. The method according to claim 9, characterized in that The step of determining the glue coating edge line of the target cathode sheet according to the cathode image data includes: Determining the edge type of the glue coating of the target cathode sheet according to the pixel distribution in the cathode image data, wherein the edge type includes: wavy edge and gradient edge; In the case where the edge type of the target cathode sheet is a wavy edge, a trough of the wavy edge is selected to determine the edge line of the target cathode sheet, wherein the trough of the wavy edge is a position on the wavy edge closest to the edge of the target cathode sheet where the glue is away from the film area; When the edge type of the target cathode film is a gradient edge, the first target boundary line on the target cathode film is determined as the glue edge line of the target cathode film, wherein the difference between the first average grayscale of each pixel point in the film area divided by the first target boundary line and the second average grayscale of each pixel point in the glue area is greater than the first set threshold.

11. The method according to claim 10, characterized in that The step of determining the edge type of the glue coating of the target cathode sheet according to the pixel distribution in the cathode image data includes: Performing edge grabbing processing from the edge of the target cathode sheet away from the film area toward the film area of ​​the target cathode sheet, and selecting a specified number of continuous pixel points in a first direction to calculate real-time grayscale values; When the difference between the real-time grayscale value and the grayscale value of the pixel points at the glue coating edge of the target cathode sheet is greater than a second set threshold, the selected specified number of consecutive pixel points are determined to be part of the glue coating edge line, and the first direction is a direction parallel to the glue coating edge; When the difference between the real-time grayscale value and the grayscale value of the pixel point at the glue edge of the target cathode film is not greater than the second set threshold, the method is translated in a second direction perpendicular to the first direction to select a specified number of continuous pixel points again to calculate the real-time grayscale value until the glue edge line of the target cathode film is determined, and the glue edge type is determined according to the shape of the glue edge line.

12. A pole piece winding detection device, characterized in that: include: A first acquisition module is used to acquire cathode image data of a target cathode sheet; A second acquisition module is used to acquire first anode image data of a first anode sheet on a first side in a thickness direction of the target cathode sheet; a third acquisition module, configured to acquire second anode image data of a second anode sheet on a second side in a thickness direction of the target cathode sheet; a first determining module, configured to determine a width difference of a first side according to the cathode image data and the first anode image data; The second determining module is configured to determine a width difference of the second side according to the cathode image data and the second anode image data.

13. A pole piece winding detection system, characterized in that: include: a first acquisition device for acquiring image data of a first side of the pole piece; a second acquisition device for acquiring image data of a second side of the pole piece; A processing device is used to process the data collected by the collection device to execute the steps of the pole piece winding detection method described in any one of claims 1 to 11.

Images