Battery cell pole piece alignment detection system and method

Abstract

The present application provides a detection system and method for the alignment of a battery cell pole piece, the system comprising: a winding machine, comprising a winding roller, for winding a battery cell, the battery cell comprising a positive pole piece and a negative pole piece, the positive pole piece is provided with a plurality of positive pole ears, and an insulating portion is provided along the head and the tail, the positive pole ear and the positive pole piece are at a first distance, and the insulating portion and the positive pole piece are at a second distance; an image acquisition device, arranged toward the winding roller, for capturing a first image of the positive pole piece and the negative pole piece that have been wound onto the winding roller during the battery cell winding process, the first image comprising the negative pole piece and the positive pole ear and the insulating portion protruding from the negative pole piece; a processor, for determining, according to the first image, a third distance between the positive pole ear and the negative pole piece, and a fourth distance between the insulating portion and the negative pole piece; and performing battery cell pole piece alignment detection based on the first distance, the second distance, the third distance and the fourth distance. The reliability of battery cell pole piece alignment detection is improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery cell winding, and in particular to a detection system and method for battery cell pole piece alignment. Background Art

[0002] During the battery cell winding process, the alignment of the electrodes needs to be tested. Currently, the relative positions of the positive and negative electrodes are usually obtained before winding for alignment testing. However, since there is no tension constraint when the head and tail of the positive electrode are cut off, the actual relative positions of the positive and negative electrodes may change during winding, resulting in inaccurate results of the battery cell electrode alignment test. Summary of the invention

[0003] The embodiments of the present application provide a system and method for detecting the alignment of battery cell pole pieces, so as to solve the technical problem of inaccurate results of detecting the alignment of battery cell pole pieces.

[0004] In a first aspect, an embodiment of the present application provides a detection system for alignment of a battery cell electrode, comprising:

[0005] A winding machine, comprising a winding roller, for winding a battery cell, wherein the battery cell comprises a positive electrode sheet and a negative electrode sheet, wherein a plurality of positive electrode tabs are arranged on the positive electrode sheet, and an insulating portion is arranged at the head and the tail of the positive electrode sheet along the extension direction of the positive electrode tab, wherein in the extension direction of the positive electrode tab, there is a first distance between the positive electrode tab and the positive electrode sheet, and there is a second distance between the insulating portion and the positive electrode sheet;

[0006] An image acquisition device is arranged on a winding roller facing the winding machine, and is used to capture a first image of the positive electrode sheet and the negative electrode sheet being wound onto the winding roller during the winding process of the battery cell, wherein the first image includes the negative electrode sheet and the positive electrode ear and the insulating portion protruding from the negative electrode sheet along the extension direction of the positive electrode ear;

[0007] The processor is communicatively connected to the image acquisition device, and is used to determine, based on the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab; and perform battery cell electrode sheet alignment detection based on the first distance, the second distance, the third distance and the fourth distance.

[0008] In this way, the positive pole ear on the positive pole piece and the insulating part at the head and tail of the positive pole piece can be used as reference objects. Since the distance between the positive pole ear and the insulating part and the positive pole piece is known, the distance between the positive pole ear and the insulating part and the negative pole ear can be calculated through the first image. Combined with the distance between the positive pole ear and the insulating part and the positive pole piece, the relative position of the positive pole piece and the negative pole piece can be obtained to detect the alignment of the battery cell pole pieces. In this way, the alignment of the battery cell pole pieces can be detected based on the first image during the winding process. At this time, the relative position of the positive pole piece and the negative pole piece is accurate, thereby improving the reliability of the alignment detection of the battery cell pole pieces.

[0009] In some embodiments, the image acquisition device includes:

[0010] A camera is connected to the winding roller via a bracket, and the camera's field of view faces the winding roller, and is used to capture a first image of the battery cell being wound on the winding roller;

[0011] The light source is arranged between the camera and the winding roller, and the light of the light source is directed toward the battery cell.

[0012] In this way, by illuminating the wound battery cell on the winding roller with a light source, the camera can capture a clearer first image, thereby improving the reliability of the battery cell pole piece alignment detection.

[0013] In some embodiments, the system further comprises:

[0014] The unloading mechanism is arranged downstream of the winding machine, and is used to place the battery cells whose battery cell electrode alignment does not meet the qualified alignment conditions to the position of the unqualified battery cells.

[0015] In this way, the battery cells whose battery cell electrode alignment does not meet the qualified alignment conditions can be placed in the position of unqualified battery cells, so that the unqualified battery cells can be destroyed or repaired later, thereby improving the yield rate of the battery cells.

[0016] In some embodiments, the system further comprises:

[0017] A laser emitting device is arranged on a side of the image acquisition device away from the winding roller, and is used to emit a laser beam to the positive electrode sheet or the negative electrode sheet to display a laser mark of a standard length on the positive electrode sheet or the negative electrode sheet;

[0018] The processor is also used to:

[0019] Determine a target length of the laser mark according to a first image with the laser mark captured by the image acquisition device;

[0020] The accuracy of the image acquisition device is tested based on the standard length and the target length.

[0021] In this way, a laser mark of standard length can be displayed on the positive electrode sheet or the negative electrode sheet by emitting a laser beam, and the target length of the laser mark in the first image and the standard length can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0022] In some embodiments, the processor is further configured to:

[0023] Determine, according to the first image, a fifth distance between at least three target electrode tabs and the positive electrode sheet, wherein the at least three target electrode tabs include at least one positive electrode tab located in a head region of the positive electrode sheet, at least one positive electrode tab located in a tail region of the positive electrode sheet, and at least one positive electrode tab located in a middle region of the positive electrode sheet;

[0024] The accuracy of the image acquisition device is detected based on the fifth distance.

[0025] In this way, the fifth distance between at least three target pole ears located in the head area, middle area and tail area of ​​the positive electrode sheet and the positive electrode sheet in the first image can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted, thereby preventing the image acquisition device from being fooled and improving the reliability of the battery cell electrode sheet alignment detection results.

[0026] In a second aspect, an embodiment of the present application further provides a method for detecting the alignment of a battery cell electrode, which is applied to the detection system of the first aspect, and the method comprises:

[0027] Acquire a first image in which the positive electrode sheet and the negative electrode sheet have been wound onto a winding roller during the winding process of the battery cell, the battery cell comprising a positive electrode sheet and a negative electrode sheet, a plurality of positive electrode tabs being arranged on the positive electrode sheet, and an insulating portion being arranged at the head and the tail of the positive electrode sheet along the extension direction of the positive electrode tab, wherein in the extension direction of the positive electrode tab, a first distance exists between the positive electrode tab and the positive electrode sheet, and a second distance exists between the insulating portion and the positive electrode sheet, and the first image comprises the negative electrode sheet and the positive electrode tab and the insulating portion protruding from the negative electrode sheet along the extension direction of the positive electrode tab;

[0028] Determine, according to the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab;

[0029] The battery cell pole piece alignment is detected based on the first distance, the second distance, the third distance and the fourth distance.

[0030] In this way, the positive pole ear on the positive pole piece and the insulating part at the head and tail of the positive pole piece can be used as reference objects. Since the distance between the positive pole ear and the insulating part and the positive pole piece is known, the distance between the positive pole ear and the insulating part and the negative pole ear can be calculated through the first image. Combined with the distance between the positive pole ear and the insulating part and the positive pole piece, the relative position of the positive pole piece and the negative pole piece can be obtained to detect the alignment of the battery cell pole pieces. In this way, the alignment of the battery cell pole pieces can be detected based on the first image during the winding process. At this time, the relative position of the positive pole piece and the negative pole piece is accurate, thereby improving the reliability of the alignment detection of the battery cell pole pieces.

[0031] In some embodiments, the cell electrode alignment detection is performed based on the first distance, the second distance, the third distance, and the fourth distance, including:

[0032] determining a first difference between the first distance and the third distance, and a second difference between the second distance and the fourth distance;

[0033] The battery cell pole piece alignment is detected based on the first difference and the second difference.

[0034] In this way, the relative position of the positive electrode sheet and the negative electrode sheet can be more accurately reflected based on the first difference between the first distance and the third distance, and the second difference between the second distance and the fourth distance, thereby improving the reliability of the battery cell electrode sheet alignment detection.

[0035] In some embodiments, the battery cell electrode alignment detection is performed based on the first difference and the second difference, including:

[0036] When the first difference is smaller than the preset first threshold, or the second difference is smaller than the first threshold, it is determined that the alignment of the battery cell pole pieces does not meet the qualified alignment condition.

[0037] In this way, when the first difference or the second difference is less than the first threshold, it can be considered that there is a risk that the negative electrode plate cannot completely cover the positive electrode plate, and it can be determined that the alignment of the battery cell plates does not meet the qualified alignment conditions.

[0038] In some embodiments, determining, according to the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab, comprises:

[0039] Extracting the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode sheet from the first image;

[0040] Determining a third distance between the positive electrode tab and the negative electrode sheet according to an edge line of the positive electrode tab and an edge line of the negative electrode sheet;

[0041] A fourth distance between the insulating portion and the negative electrode sheet is determined according to an edge line of the insulating portion and an edge line of the negative electrode sheet.

[0042] In this way, the edge line of the positive electrode lug, the edge line of the insulating part and the edge line of the negative electrode sheet in the first image can be extracted to calculate the third distance between the positive electrode lug and the negative electrode sheet, and the fourth distance between the insulating part and the negative electrode sheet, laying the foundation for subsequent battery cell electrode sheet alignment detection.

[0043] In some embodiments, extracting the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode tab from the first image includes:

[0044] determining a region of interest in the first image;

[0045] According to the region of interest, determine the pole lug region, the insulating portion region and the pole piece region in the first image;

[0046] The tab area, the insulating part area and the pole piece area are edge-grabbed to obtain the edge line of the positive tab, the edge line of the insulating part and the edge line of the negative pole piece.

[0047] In this way, the pole lug area, insulating part area and pole piece area in the first image can be determined based on the area of ​​interest, and these areas can be processed by edge grabbing to obtain accurate edge lines of the positive pole lug, the insulating part and the negative pole piece, and then the accurate third distance and fourth distance can be calculated, thereby improving the reliability of subsequent battery cell pole piece alignment detection.

[0048] In some embodiments, after detecting the alignment of the battery cell pole pieces based on the first distance, the second distance, the third distance, and the fourth distance, the method further includes:

[0049] When the alignment of the battery cell pole pieces does not meet the qualified alignment condition, a first warning message is output.

[0050] In this way, a first warning message can be output when the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, so that the operator can adjust the relevant equipment for battery cell winding according to the first warning message to improve the compliance rate of the battery cell pole piece alignment, thereby improving the yield rate of the battery cell.

[0051] In some embodiments, after performing the cell electrode alignment detection based on the first distance, the second distance, the third distance, and the fourth distance, the method further includes:

[0052] When the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, the unloading mechanism is controlled to place the battery cell at the position of the unqualified battery cell.

[0053] In this way, the battery cells whose battery cell electrode alignment does not meet the qualified alignment conditions can be placed in the position of unqualified battery cells, so that the unqualified battery cells can be destroyed or repaired later, thereby improving the yield rate of the battery cells.

[0054] In some embodiments, the method further comprises:

[0055] Determine, according to the first image, a fifth distance between at least three target electrode tabs and the positive electrode sheet, wherein the at least three target electrode tabs include at least one positive electrode tab located in a head region of the positive electrode sheet, at least one positive electrode tab located in a tail region of the positive electrode sheet, and at least one positive electrode tab located in a middle region of the positive electrode sheet;

[0056] The accuracy of the image acquisition device is detected based on the fifth distance.

[0057] In this way, the fifth distance between at least three target pole ears located in the head area, middle area and tail area of ​​the positive electrode sheet and the positive electrode sheet in the first image can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted, thereby preventing the image acquisition device from being fooled and improving the reliability of the battery cell electrode sheet alignment detection results.

[0058] In some embodiments, when the number of target tabs is three, the target tabs include a first positive tab, a last positive tab, and an intermediate tab among the plurality of positive tabs;

[0059] Among them, the difference between the first number of spaced-apart pole tabs and the second number of spaced-apart pole tabs is less than or equal to 1, the first number of spaced-apart pole tabs is the number of spaced-apart pole tabs between the first positive pole tab and the middle pole tab, and the second number of spaced-apart pole tabs is the number of spaced-apart pole tabs between the last positive pole tab and the middle pole tab.

[0060] In this way, the distribution of the target tabs is more uniform and reasonable, which improves the reliability of the precision detection of the image acquisition device.

[0061] In some embodiments, performing accuracy detection of the image acquisition device based on the fifth distance includes:

[0062] Determine a third difference value corresponding to any two target tabs according to a fifth distance between at least three target tabs and the positive electrode sheet;

[0063] The accuracy of the image acquisition device is detected based on the third difference value corresponding to any two target tabs.

[0064] In this way, the third difference corresponding to the fifth distance between any two target pole ears and the positive electrode sheet can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0065] In some embodiments, performing accuracy detection of the image acquisition device based on the third difference value corresponding to any two target tabs includes:

[0066] When any third difference between the third differences corresponding to any two target tabs is greater than a preset second threshold, determining that the accuracy of the image acquisition device does not meet the accuracy requirement;

[0067] The second threshold is a critical value of the third difference between any two target tabs when the accuracy of the image acquisition device does not meet the accuracy requirement.

[0068] In this way, when any third difference between any two target tabs is greater than the third threshold, it can be considered that the accuracy of the image acquisition device has deteriorated and the cell pole piece alignment detection result is affected by the accuracy of the image acquisition device and is unreliable.

[0069] In some embodiments, performing accuracy detection of the image acquisition device based on the third difference value corresponding to any two target tabs includes:

[0070] Determine the maximum value of the third difference from the third difference values ​​corresponding to any two target tabs;

[0071] When the maximum value of the third difference is greater than a preset second threshold, determining that the accuracy of the image acquisition device does not meet the accuracy requirement;

[0072] The second threshold is a critical value of the third difference between any two target tabs when the accuracy of the image acquisition device does not meet the accuracy requirement.

[0073] In this way, the maximum value of the third difference can be determined and compared with the second threshold to detect whether the accuracy of the image acquisition device does not meet the accuracy requirement, without traversing all the third differences, which effectively saves computing power.

[0074] In some embodiments, the method further comprises:

[0075] Acquire a first image with a laser mark during the winding process of the battery cell, where the laser mark is a laser mark of a standard length displayed on the positive electrode sheet or the negative electrode sheet by emitting a laser beam from a laser emitting device;

[0076] determining a target length of the laser mark based on the first image with the laser mark;

[0077] The accuracy of the image acquisition device is tested based on the standard length and the target length.

[0078] In this way, a laser mark of standard length can be displayed on the positive electrode sheet or the negative electrode sheet by emitting a laser beam, and the target length of the laser mark in the first image and the standard length can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0079] In some embodiments, the accuracy detection of the image acquisition device based on the standard length and the target length includes:

[0080] When the difference between the standard length and the target length is greater than a preset third threshold, it is determined that the accuracy of the image acquisition device does not meet the accuracy requirement.

[0081] In this way, the difference between the target length of the laser mark and the standard length can be used to detect whether the accuracy of the image acquisition device deteriorates during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell pole piece alignment detection results.

[0082] In some embodiments, the method further comprises:

[0083] When the accuracy of the image acquisition device does not meet the accuracy requirement, a second warning message is output.

[0084] In this way, the second warning information can be output when the accuracy of the image acquisition device does not meet the accuracy requirement, so that the operator can adjust the parameters of the image acquisition device according to the second warning information to improve the accuracy of the image acquisition device.

[0085] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0087] Figure 1 One of the schematic diagrams of the battery cell pole piece alignment detection system provided in the embodiment of the present application;

[0088] Figure 2 A schematic diagram of the winding relationship between the battery cell pole piece and the winding roller provided in an embodiment of the present application;

[0089] Figure 3 The second schematic diagram of the battery cell electrode alignment detection system provided in the embodiment of the present application;

[0090] Figure 4 A schematic diagram of a battery cell after winding is completed provided in an embodiment of the present application;

[0091] Figure 5 A schematic diagram of a first distance between positive electrode tabs provided in an embodiment of the present application;

[0092] Figure 6 A schematic diagram of a second distance of an insulating portion provided in an embodiment of the present application;

[0093] Figure 7 A schematic diagram of a third distance between the positive electrode tab and the negative electrode sheet provided in an embodiment of the present application;

[0094] Figure 8 A schematic diagram of a fourth distance between the insulating portion and the negative electrode sheet provided in an embodiment of the present application;

[0095] Fig. 9 A schematic diagram of a target tab provided in an embodiment of the present application;

[0096] Fig.10 A schematic flow chart of a method for detecting the alignment of battery cell pole pieces provided in an embodiment of the present application.

[0097] In the drawings, the drawings are not drawn to scale.

[0098] Reference numerals:

[0099] 100, battery cell; 101, positive electrode sheet; 1011, positive electrode tab; 1012, insulating portion; 102, negative electrode sheet; 1021, negative electrode tab; 103, target tab; 104, diaphragm;

[0100] 110, winding machine; 111, winding roller; 120, image acquisition device; 121, camera; 122, light source; 130, laser emitting device;

[0101] ΔL21, first distance; ΔL22, second distance; ΔL11, third distance; ΔL12, fourth distance. DETAILED DESCRIPTION

[0102] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0103] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0104] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0105] In the related art, the alignment of the battery cell pole pieces can generally be detected by identifying the relative positions of the edges of the positive pole piece and the negative pole piece. It is understandable that during the winding process of the battery cell, the negative pole piece needs to cover the positive pole piece, which makes it impossible to identify the edge of the positive pole piece from the image of the battery cell being wound. Therefore, it is necessary to take an image of the battery cell before the positive pole piece is wound, and predict the relative position of the positive pole piece with the negative pole piece when winding based on the image.

[0106] However, the applicant found that during the rolling and final finishing stages, since the head and tail of the positive electrode sheet are cut off without tension, interference from external factors such as the airflow inside the winder before winding or abnormal incoming materials may cause a deviation between the position of the positive electrode sheet before winding and the actual winding position, resulting in inaccurate relative position of the positive electrode sheet with the negative electrode sheet during winding, which in turn causes inaccurate results in the battery cell electrode sheet alignment detection.

[0107] Based on this, the embodiment of the present application provides a detection system and method for the alignment of battery cell pole pieces to solve the above technical problems. The following first introduces the detection system for the alignment of battery cell pole pieces provided in the embodiment of the present application.

[0108] See also Figure 1, the embodiment of the present application provides a detection system for the alignment of a battery cell electrode, which may include:

[0109] The winding machine 110 includes a winding roller 111 for winding a battery cell 100, wherein the battery cell 100 includes a positive electrode sheet 101 and a negative electrode sheet 102, wherein a plurality of positive electrode tabs 1011 are provided on the positive electrode sheet 101, and an insulating portion 1012 is provided at the head and the tail of the positive electrode sheet 101 along the extension direction of the positive electrode tab 1011, wherein in the extension direction of the positive electrode tab 1011, there is a first distance ΔL21 between the positive electrode tab 1011 and the positive electrode sheet 101, and there is a second distance ΔL22 between the insulating portion 1012 and the positive electrode sheet 101;

[0110] The image acquisition device 120 is disposed on the winding roller 111 facing the winding machine 110, and is used to capture a first image of the positive electrode sheet 101 and the negative electrode sheet 102 being wound onto the winding roller 111 during the winding process of the battery cell 100, wherein the first image includes the negative electrode sheet 102 and the positive electrode tab 1011 and the insulating portion 1012 protruding from the negative electrode sheet 102 along the extension direction of the positive electrode tab 1011;

[0111] The processor is communicatively connected to the image acquisition device 120, and is used to determine, based on the first image, a third distance ΔL11 between the positive pole ear 1011 and the negative pole piece 102, and a fourth distance ΔL12 between the insulating portion 1012 and the negative pole piece 102 in the extension direction of the positive pole ear 1011; and perform battery cell pole piece alignment detection based on the first distance ΔL21, the second distance ΔL22, the third distance ΔL11 and the fourth distance ΔL12.

[0112] like Figure 1 As shown, the detection system for the alignment of the battery cell pole piece may include a winding machine 110, an image acquisition device 120 and a processor (not shown in the figure). The winding machine 110 may include a winding roller 111, and the winding roller 111 is used to wind the battery cell 100, wherein the battery cell 100 may include a positive pole piece 101 and a negative pole piece 102, and a plurality of positive pole tabs 1011 are arranged on the positive pole piece 101, and an insulating portion 1012 may be arranged at the head and tail of the positive pole piece 101, and the extension direction of the insulating portion 1012 may be the same as the extension direction (X) of the positive pole tab 1011. Generally speaking, a plurality of negative pole tabs 1021 may also be arranged on the negative pole piece 102.

[0113] like Figure 2 As shown in FIG. 1 , during the process of winding the battery cell by the winding roller 111 , the positive electrode sheet 101 , the separator 104 , the negative electrode sheet 102 and the separator 104 are arranged in sequence and then wound. Figure 4 shown.

[0114] It is understandable that if Figure 5 and Figure 7 As shown, the distance between the positive electrode tab 1011 and the positive electrode sheet 101 in the extension direction (X) of the positive electrode tab 1011 may be a first distance ΔL21, and the distance between the insulating portion 1012 and the positive electrode sheet 101 in the extension direction (X) of the positive electrode tab 1011 may be a second distance ΔL22. The first distance ΔL21 may be considered as the length of the positive electrode tab 1011, and the second distance ΔL22 may be considered as the length of the insulating portion 1012. The first distance ΔL21 and the second distance ΔL22 may be obtained in the die-cutting section before the battery cell 100 is wound, that is, the first distance ΔL21 and the second distance ΔL22 are known values.

[0115] It can also be understood that the first distance ΔL21 and the second distance ΔL22 can be the same value or different values, which is not specifically limited here.

[0116] The image acquisition device 120 can be fixed at a position separated from the positive electrode sheet 101 and the negative electrode sheet 102 by a connection bracket on the winding machine 110, and is arranged toward the winding roller 111. The preset distance can be set according to an empirical value, with the purpose of capturing a clearer and more comprehensive first image during the winding process of the battery cell 100, and is not specifically limited here. For example, the preset distance can be 70 mm.

[0117] The processor may receive the first image captured by the image acquisition device 120, extract the edge line of the positive electrode tab 1011 or the insulating portion 1012 from the first image, and extract the edge line of the negative electrode tab 102. Figure 6 and Figure 8 As shown, a third distance ΔL11 between the positive electrode tab 1011 and the negative electrode tab 102 and a fourth distance ΔL12 between the insulating portion 1012 and the negative electrode tab 102 may be determined based on the extracted edge line.

[0118] The alignment of the cell pole pieces can be detected based on the first distance ΔL21, the second distance ΔL22, the third distance ΔL11, and the fourth distance ΔL12. For example, the relative position determined by the first distance ΔL21 and the third distance ΔL11 can reflect the alignment of the positive pole piece 101 and the negative pole piece 102 at other parts except the head and the tail. The relative position determined by the second distance ΔL221 and the fourth distance ΔL12 can reflect the alignment of the positive pole piece 101 and the negative pole piece 102 at the head and the tail.

[0119] In this way, the positive pole tab 1011 on the positive pole sheet 101 and the insulating portion 1012 at the head and tail of the positive pole sheet 101 can be used as reference objects. Since the distance between the positive pole tab 1011 and the insulating portion 1012 and the positive pole sheet 101 is known, the distance between the positive pole tab 1011 and the insulating portion 1012 and the negative pole tab 1021 can be calculated through the first image. Combined with the distance between the positive pole tab 1011 and the insulating portion 1012 and the positive pole sheet 101, the relative position of the positive pole sheet 101 and the negative pole sheet 102 can be obtained to detect the alignment of the battery cell pole sheets. In this way, the alignment of the battery cell pole sheets can be detected based on the first image during the winding process. At this time, the relative position of the positive pole sheet 101 and the negative pole sheet 102 is accurate, thereby improving the reliability of the detection of the alignment of the battery cell pole sheets.

[0120] In some embodiments, the image acquisition device 120 may include:

[0121] The camera 121 is connected to the winding roller 111 through a bracket (not shown in the figure), and the field of view of the camera 121 is toward the winding roller 111, and is used to capture a first image of the battery cell 100 being wound on the winding roller 111;

[0122] The light source 122 is disposed between the camera 121 and the winding roller 111 , and the light of the light source 122 is directed toward the battery cell 100 .

[0123] like Figure 2 As shown, in this embodiment, the image acquisition device 120 may include a camera 121 and a light source 122, wherein the camera 121 may be fixedly connected to the winding roller 111 of the winder 110 via a bracket, and the field of view of the camera 121 may be toward the winding roller 111 so as to be able to capture a first image of the battery cell 100 being wound on the winding roller 111.

[0124] The light source 122 may be disposed between the camera 121 and the winding roller 111, and the light from the light source 122 may be irradiated toward the battery cell 100 to illuminate the wound battery cell 100. When the light source 122 illuminates the battery cell 100, the camera 121 may capture a first image of the battery cell 100 being wound on the winding roller 111.

[0125] In some examples, the light source 122 may also be disposed on a side of the camera away from the winder 110 , which is not specifically limited herein.

[0126] In this way, by irradiating the wound battery cell 100 with the light source 122 , the camera 121 can capture a clearer first image, thereby improving the reliability of the battery cell electrode alignment detection.

[0127] In some embodiments, the system may further include:

[0128] The unloading mechanism (not shown in the figure) is arranged downstream of the winding machine 110, and is used to place the battery cells 100 whose battery cell electrode alignment does not meet the qualified alignment condition to the position of the unqualified battery cells.

[0129] In this embodiment, if the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, the battery cell 100 can be considered as a defective product. At this time, the unloading mechanism can place the defective battery cell 100 to the position of the defective battery cell, such as the NG platform.

[0130] In this way, the battery cells 100 whose battery cell electrode alignment does not meet the qualified alignment conditions can be placed in the position of unqualified battery cells 100, so that the unqualified battery cells 100 can be destroyed or repaired later, thereby improving the yield rate of the battery cells 100.

[0131] In some embodiments, the detection system further comprises:

[0132] The laser emitting device 130 is disposed on a side of the image acquisition device 120 away from the winding roller 111, and is used to emit a laser beam to the positive electrode sheet 101 or the negative electrode sheet 102, so as to display a laser mark of a standard length on the positive electrode sheet 101 or the negative electrode sheet 102;

[0133] The image acquisition device 120 is also used to: capture a first image with a laser mark during the winding process of the battery cell 100;

[0134] The processor is also used to:

[0135] Determine a target length of the laser mark according to the first image with the laser mark captured by the image acquisition device 120;

[0136] The accuracy of the image acquisition device 120 is checked based on the standard length and the target length.

[0137] In the present embodiment, it is understandable that as the battery cell 100 is rolled thicker and thicker on the winding machine 110, the accuracy of the image acquisition device 120 may be affected after working for a long time, resulting in poor accuracy. The first difference and the second difference obtained based on the first image are not accurate enough, resulting in unreliable battery cell electrode alignment detection results.

[0138] Based on this, Figure 3 As shown, the detection system for the alignment of the battery cell pole piece may also include a laser emitting device 130, which may emit a laser beam to the positive pole piece 101 or the negative pole piece 102 to display a light spot on the positive pole piece 101 or the negative pole piece 102, and the light spot is a laser mark with a standard length. The standard length of the laser mark is related to the parameters of the laser beam emitted by the laser emitting device 130. For example, if the laser emitting device emits a laser beam with a width of 0.5 mm, the standard length of the laser mark is 0.5 mm.

[0139] The image acquisition device 120 can capture a first image with a laser mark. It is understandable that the laser emitting device 130 can continuously emit a laser beam during the entire process of the winding roller 111 winding the battery cell, so that the light spot of the laser beam, that is, the laser mark, can be displayed on each first image. The laser emitting device 130 can also emit a laser beam at a predetermined number of winding layers. For example, a laser beam can be emitted once within a preset number of layers at the beginning of winding, a laser beam can be emitted once when winding to the middle number of layers, and a laser beam can be emitted again within a preset number of layers at the end of winding. The specific working mode of the laser emitting device 130 can be set according to actual needs and is not specifically limited here.

[0140] Normally, the target length of the laser mark calculated in each first image taken should be equal to the standard length. Therefore, the accuracy of the image acquisition device 120 can be detected by the standard length and the target length. If the standard length and the target length deviate greatly, it can be considered that the first image is distorted, that is, at this time, it can be considered that the accuracy of the image acquisition device 120 does not meet the accuracy requirements.

[0141] In this way, a laser mark of standard length can be displayed on the positive electrode sheet 101 or the negative electrode sheet 102 by emitting a laser beam, and the target length of the laser mark in the first image and the standard length can be used to further determine whether the accuracy of the image acquisition device 120 deteriorates during the entire winding process of the battery cell 100, which may cause the first image to be distorted. This can prevent the image acquisition device 120 from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0142] In some embodiments, the processor is further configured to:

[0143] Determine, according to the first image, a fifth distance between at least three target pole tabs 103 and the positive electrode sheet 101, wherein the at least three target pole tabs 103 include at least one positive pole tab 1011 located in a head region of the positive electrode sheet 101, at least one positive pole tab 1011 located in a tail region of the positive electrode sheet 101, and at least one positive pole tab 1011 located in a middle region of the positive electrode sheet 101;

[0144] The accuracy of the image acquisition device 120 is detected based on the fifth distance.

[0145] In this embodiment, at least three target tabs 103 may be determined from a plurality of positive tabs 1011. The at least three target tabs 103 include at least one positive tab 1011 located in the head region of the positive electrode sheet 101, at least one positive tab 1011 located in the tail region of the positive electrode sheet 101, and at least one positive tab 1011 located in the middle region of the positive electrode sheet 101.

[0146] It can be understood that the positive electrode tabs 1011 in the head region of the positive electrode sheet 101 may be a preset number of positive electrode tabs 1011 located at the head of the positive electrode sheet 101. For example, the first five positive electrode tabs 1011 of the positive electrode sheet 101 may be determined as the positive electrode tabs 1011 in the head region. The positive electrode tabs 1011 in the middle region of the positive electrode sheet 101 may be a preset number of positive electrode tabs 1011 located in the middle of the positive electrode sheet 101. For example, the five positive electrode tabs 1011 in the middle of the positive electrode sheet 101 may be determined as the positive electrode tabs 1011 in the head region. The positive electrode tabs 1011 in the tail region of the positive electrode sheet 101 may be a preset number of positive electrode tabs 1011 located at the tail of the positive electrode sheet 101. For example, the last five positive electrode tabs 1011 of the positive electrode sheet 101 may be determined as the positive electrode tabs 1011 in the tail region.

[0147] The fifth distance between the target electrode tab 103 and the positive electrode sheet 101 can be calculated from the first image. Normally, in the first image, the fifth distance between each positive electrode tab 1011 and the positive electrode sheet 101 should be equal to the first distance ΔL21 between the positive electrode tab 1011 and the positive electrode sheet 101. Therefore, the accuracy of the image acquisition device 120 can be detected based on the fifth distance and the first distance ΔL21. If there is a large deviation between the fifth distance and the first distance ΔL21, it can be considered that the first image is distorted.

[0148] In this way, the fifth distance between at least three target pole ears 103 located in the head area, middle area and tail area of ​​the positive pole sheet 101 in the first image and the positive pole sheet 101 can be used to detect whether the accuracy of the image acquisition device 120 deteriorates during the entire winding process of the battery cell 100, which may cause the first image to be distorted, thereby preventing the image acquisition device 120 from being fooled and improving the reliability of the battery cell pole sheet alignment detection results.

[0149] See also Fig.10 The present application also provides a method for detecting the alignment of a cell electrode, which is applied to the above-mentioned detection system. The detection method may include:

[0150] Step 601, obtaining a first image in which the positive electrode sheet and the negative electrode sheet have been wound onto a winding roller of a winding machine during the winding process of the battery cell, the battery cell comprising a positive electrode sheet and a negative electrode sheet, a plurality of positive electrode tabs being arranged on the positive electrode sheet, and an insulating portion being arranged at the head and the tail of the positive electrode sheet along the extension direction of the positive electrode tab, wherein in the extension direction of the positive electrode tab, there is a first distance between the positive electrode tab and the positive electrode sheet, and there is a second distance between the insulating portion and the positive electrode sheet, and the first image comprises the negative electrode sheet and the positive electrode tab and the insulating portion protruding from the negative electrode sheet along the extension direction of the positive electrode tab;

[0151] Step 602, determining, based on the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab;

[0152] Step 603 , performing cell pole piece alignment detection based on the first distance, the second distance, the third distance and the fourth distance.

[0153] It can be understood that the specific implementation of steps 601 to 603 is the same as the operating steps of the processor in the above-mentioned detection system, and will not be described in detail here.

[0154] In this way, the positive pole ear on the positive pole piece and the insulating part at the head and tail of the positive pole piece can be used as reference objects. Since the distance between the positive pole ear and the insulating part and the positive pole piece is known, the distance between the positive pole ear and the insulating part and the negative pole ear can be calculated through the first image. Combined with the distance between the positive pole ear and the insulating part and the positive pole piece, the relative position of the positive pole piece and the negative pole piece can be obtained to detect the alignment of the battery cell pole pieces. In this way, the alignment of the battery cell pole pieces can be detected based on the first image during the winding process. At this time, the relative position of the positive pole piece and the negative pole piece is accurate, thereby improving the reliability of the alignment detection of the battery cell pole pieces.

[0155] In some embodiments, performing cell pole piece alignment detection based on the first distance, the second distance, the third distance, and the fourth distance may include:

[0156] determining a first difference between the first distance and the third distance, and a second difference between the second distance and the fourth distance;

[0157] The battery cell pole piece alignment is detected based on the first difference and the second difference.

[0158] In this embodiment, a first difference D1 between the first distance ΔL21 and the third distance ΔL11 may be calculated, where D1=|ΔL21︱-|ΔL11︱, and a second difference D2 between the second distance ΔL22 and the fourth distance ΔL12 may be calculated, where D2=|ΔL22︱-|ΔL12︱. The first difference D1 may represent the alignment of the positive electrode sheet and the negative electrode sheet at other parts except the head and the tail. The second difference D2 may represent the alignment of the positive electrode sheet and the negative electrode sheet at the head and the tail.

[0159] The first difference D1 and the second difference D2 can be compared with a preset first threshold, wherein the first threshold can be a critical value for the positive electrode sheet and the negative electrode sheet to meet the qualified alignment requirement. The detection result of the alignment of the battery cell electrode sheets can be obtained according to the comparison result.

[0160] In this way, the relative position of the positive electrode sheet and the negative electrode sheet can be more accurately reflected based on the first difference between the first distance and the third distance, and the second difference between the second distance and the fourth distance, thereby improving the reliability of the battery cell electrode sheet alignment detection.

[0161] In some embodiments, performing cell electrode alignment detection based on the first difference and the second difference may include:

[0162] When the first difference is smaller than the preset first threshold, or the second difference is smaller than the first threshold, it is determined that the alignment of the battery cell pole pieces does not meet the qualified alignment condition.

[0163] In this embodiment, the preset first threshold value can be set according to actual experience and is not specifically limited here. For example, the first threshold value can be 0.2 mm.

[0164] The first difference and the second difference can be compared with the first threshold. If the first difference or the second difference is smaller than the first threshold, it can be considered that the edge of the negative electrode plate is very close to the edge of the positive electrode plate. At this time, the negative electrode plate may not be able to completely cover the positive electrode plate, resulting in the risk of defective battery cells.

[0165] In this way, when the first difference or the second difference is less than the first threshold, it can be considered that there is a risk that the negative electrode plate cannot completely cover the positive electrode plate, and it can be determined that the alignment of the battery cell plates does not meet the qualified alignment conditions.

[0166] In some embodiments, determining, according to the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab may include:

[0167] Extracting the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode sheet from the first image;

[0168] Determining a third distance between the positive electrode tab and the negative electrode sheet according to an edge line of the positive electrode tab and an edge line of the negative electrode sheet;

[0169] A fourth distance between the insulating portion and the negative electrode sheet is determined according to an edge line of the insulating portion and an edge line of the negative electrode sheet.

[0170] In this embodiment, the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode sheet can be extracted from the first image. For example, the grayscale image can be obtained by grayscale processing the first image, the pixel points in the grayscale image are first-order differentiated, the boundary points are determined based on the first-order derivative values, and the edge lines can be obtained based on these boundary points. The boundary points can also be determined from the first image by enhancing the image contrast, and the edge lines can be obtained based on these boundary points. The specific method of extracting the edge lines is not specifically limited here.

[0171] The third distance ΔL11 between the positive electrode tab and the negative electrode sheet can be calculated based on the pixel coordinates of the pixel points on the edge line of the positive electrode tab and the pixel coordinates of the pixel points on the edge line of the negative electrode sheet. The fourth distance ΔL12 between the insulating portion and the negative electrode sheet can also be calculated based on the pixel coordinates of the pixel points on the edge line of the insulating portion and the pixel coordinates of the pixel points on the edge line of the negative electrode sheet.

[0172] In this way, the edge line of the positive electrode lug, the edge line of the insulating part and the edge line of the negative electrode sheet in the first image can be extracted to calculate the third distance between the positive electrode lug and the negative electrode sheet, and the fourth distance between the insulating part and the negative electrode sheet, laying the foundation for subsequent battery cell electrode sheet alignment detection.

[0173] In some embodiments, extracting the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode tab from the first image includes:

[0174] determining a region of interest in the first image;

[0175] According to the region of interest, determine the pole lug region, the insulating portion region and the pole piece region in the first image;

[0176] The tab area, the insulating part area and the pole piece area are edge-grabbed to obtain the edge line of the positive tab, the edge line of the insulating part and the edge line of the negative pole piece.

[0177] In this embodiment, a region of interest (ROI) in the first image may be determined first. The ROI may be determined based on a preset template, wherein the preset template may be used to characterize the positions of the tab region, the insulation region, and the pole piece region in the image during the battery cell winding process.

[0178] The first image can be extracted by ROI to determine the tab region where the positive tab is located, the insulating region where the insulating portion is located, and the plate region where the negative pole piece is located in the first image. The tab region can be edge-grabbed to obtain the edge line of the positive tab, the insulating region can be edge-grabbed to obtain the edge line of the insulating region, and the plate region can be edge-grabbed to obtain the edge line of the negative pole piece.

[0179] For example, the first image may be processed in grayscale to obtain a grayscale image, and the first-order derivative of the pixel points in the pole lug area, the insulating part area and the pole piece area in the grayscale image may be taken, and boundary points may be determined from the pole lug area, the insulating part area and the pole piece area based on the first-order derivative values, and the edge lines corresponding to the respective areas may be obtained based on these boundary points.

[0180] In this way, the pole lug area, insulating part area and pole piece area in the first image can be determined based on the area of ​​interest, and these areas can be processed by edge grabbing to obtain accurate edge lines of the positive pole lug, the insulating part and the negative pole piece, and then the accurate third distance and fourth distance can be calculated, thereby improving the reliability of subsequent battery cell pole piece alignment detection.

[0181] In some embodiments, after detecting the alignment of the battery cell pole pieces based on the first distance, the second distance, the third distance, and the fourth distance, the method may further include:

[0182] When the alignment of the battery cell pole pieces does not meet the qualified alignment condition, a first warning message is output.

[0183] In this embodiment, if the alignment of the battery cell pole pieces does not meet the qualified alignment condition, a first warning message may be output and the winding machine may be stopped.

[0184] The first warning information can be used to remind the operator that the alignment of the battery cell pole pieces is poor, and that the relevant equipment for battery cell winding, such as the winding machine and the feeding mechanism, needs to be adjusted and repaired. It is understandable that the output method of the first warning information can be to display a prompt text on the display screen that the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, or to flash a flashlight to prompt that the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, or to sound an alarm through a buzzer to prompt that the alignment of the battery cell pole pieces does not meet the qualified alignment conditions. No specific limitation is made here.

[0185] In this way, a first warning message can be output when the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, so that the operator can adjust the relevant equipment for battery cell winding according to the first warning message to improve the compliance rate of the battery cell pole piece alignment, thereby improving the yield rate of the battery cell.

[0186] In some embodiments, after performing the cell electrode alignment detection based on the first distance, the second distance, the third distance, and the fourth distance, the method may further include:

[0187] When the alignment of the battery cell pole pieces does not meet the qualified alignment conditions, the unloading mechanism is controlled to place the battery cell at the position of the unqualified battery cell.

[0188] In this way, the battery cells whose battery cell electrode alignment does not meet the qualified alignment conditions can be placed in the position of unqualified battery cells, so that the unqualified battery cells can be destroyed or repaired later, thereby improving the yield rate of the battery cells.

[0189] In some embodiments, the method may further include:

[0190] Determine, according to the first image, a fifth distance between at least three target electrode tabs and the positive electrode sheet, wherein the at least three target electrode tabs include at least one positive electrode tab located in a head region of the positive electrode sheet, at least one positive electrode tab located in a tail region of the positive electrode sheet, and at least one positive electrode tab located in a middle region of the positive electrode sheet;

[0191] The accuracy of the image acquisition device is detected based on the fifth distance.

[0192] In this way, the fifth distance between at least three target pole ears located in the head area, middle area and tail area of ​​the positive electrode sheet and the positive electrode sheet in the first image can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted, thereby preventing the image acquisition device from being fooled and improving the reliability of the battery cell electrode sheet alignment detection results.

[0193] In some embodiments, when the number of target tabs is three, the target tabs include a first positive tab, a last positive tab, and an intermediate tab among the plurality of positive tabs;

[0194] Among them, the difference between the first number of spaced-apart pole tabs and the second number of spaced-apart pole tabs is less than or equal to 1, the first number of spaced-apart pole tabs is the number of spaced-apart pole tabs between the first positive pole tab and the middle pole tab, and the second number of spaced-apart pole tabs is the number of spaced-apart pole tabs between the last positive pole tab and the middle pole tab.

[0195] In this embodiment, if Fig. 9 As shown, a plurality of positive electrode tabs may be provided on the positive electrode sheet 101. If the number of target tabs 103 is three, the first positive electrode tab, the last positive electrode tab and the middle tab at the center may be determined as the target tabs 103.

[0196] For example, the total number of positive electrode tabs is n. If n is an odd number, the middle tab may be the (n+1) / 2th positive electrode tab. If n is an even number, the middle tab may be the n / 2th positive electrode tab, or the (n+2) / 2th positive electrode tab.

[0197] In this way, the distribution of the target tabs is more uniform and reasonable, which improves the reliability of the precision detection of the image acquisition device.

[0198] In some embodiments, performing accuracy detection of the image acquisition device based on the fifth distance may include:

[0199] Determine a third difference value corresponding to any two target tabs according to a fifth distance between at least three target tabs and the positive electrode sheet;

[0200] The accuracy of the image acquisition device is detected based on the third difference value corresponding to any two target tabs.

[0201] In this way, the third difference corresponding to the fifth distance between any two target pole ears and the positive electrode sheet can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0202] In some embodiments, performing accuracy detection of the image acquisition device based on the fifth distance may include:

[0203] Determine a third difference value corresponding to any two target tabs according to a fifth distance between at least three target tabs and the positive electrode sheet;

[0204] The accuracy of the image acquisition device is detected based on the third difference value corresponding to any two target tabs.

[0205] In this embodiment, it can be understood that, normally, in the first image, the fifth distance between each positive electrode tab and the positive electrode sheet is equal, that is, equal to the first distance ΔL21. Therefore, the third difference corresponding to any two target tabs can be calculated based on the fifth distances between at least three target tabs and the positive electrode sheet, and then the accuracy of the image acquisition device can be detected based on the third difference corresponding to any two target tabs.

[0206] In this way, the third difference corresponding to the fifth distance between any two target pole ears and the positive electrode sheet can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0207] In some embodiments, performing accuracy detection of the image acquisition device based on the third difference between any two target tabs may include:

[0208] When any third difference between the third differences corresponding to any two target tabs is greater than a preset second threshold, determining that the accuracy of the image acquisition device does not meet the accuracy requirement;

[0209] The second threshold is a critical value of the third difference between any two target tabs when the accuracy of the image acquisition device does not meet the accuracy requirement.

[0210] In this embodiment, in order to facilitate understanding of the technical solution of this embodiment, an example is given in which the number of target pole tabs is three, the fifth distance of the first positive pole tab in the first image is H1, the fifth distance of the middle pole tab in the first image is H2, and the fifth distance of the last positive pole tab in the first image is H3.

[0211] The third difference corresponding to any two target tabs can be calculated, where ΔH12=|H1-H2|, ΔH13=|H1-H3|, and ΔH23=|H2-H3|.

[0212] When any third difference between any two target tabs is greater than a preset second threshold, it can be considered that the accuracy of the image acquisition device does not meet the accuracy requirement. The preset second threshold can be set according to actual experience, for example, the second threshold can be 0.1 mm.

[0213] For example, if ΔH12>0.1mm, or ΔH13>0.1mm, or ΔH23>0.1mm, it can be considered that the accuracy of the image acquisition device does not meet the accuracy requirements. At this time, the battery cell electrode alignment detection result obtained by relying on the first image taken by the image acquisition device is unreliable.

[0214] In this way, when any third difference between any two target tabs is greater than the third threshold, it can be considered that the accuracy of the image acquisition device has deteriorated and the cell pole piece alignment detection result is affected by the accuracy of the image acquisition device and is unreliable.

[0215] In some embodiments, performing accuracy detection of the image acquisition device based on the third difference between any two target tabs may include:

[0216] Determine the maximum value of the third difference from the third difference values ​​corresponding to any two target tabs;

[0217] When the maximum value of the third difference is greater than a preset second threshold, determining that the accuracy of the image acquisition device does not meet the accuracy requirement;

[0218] The second threshold is a critical value of the third difference between any two target tabs when the accuracy of the image acquisition device does not meet the accuracy requirement.

[0219] In this embodiment, the maximum value of the third difference is determined from the third differences corresponding to any two target tabs, that is, ΔH=Max (ΔH12=|H1-H2|, ΔH13=|H1-H3|, ΔH23=|H2-H3|).

[0220] When the maximum value of the third difference is greater than the preset second threshold, it can be considered that the accuracy of the image acquisition device does not meet the accuracy requirement. For example, if ΔH>0.1mm, it can be considered that the accuracy of the image acquisition device does not meet the accuracy requirement, and the cell electrode alignment detection result obtained by relying on the first image captured by the image acquisition device is unreliable.

[0221] In this way, the maximum value of the third difference can be determined and compared with the second threshold to detect whether the accuracy of the image acquisition device does not meet the accuracy requirement, without traversing all the third differences, which effectively saves computing power.

[0222] In some embodiments, the method may further include:

[0223] Acquire a first image with a laser mark during the winding process of the battery cell, where the laser mark is a laser mark of a standard length displayed on the positive electrode sheet or the negative electrode sheet by emitting a laser beam from a laser emitting device;

[0224] determining a target length of the laser mark based on the first image with the laser mark;

[0225] The accuracy of the image acquisition device is tested based on the standard length and the target length.

[0226] In this way, a laser mark of standard length can be displayed on the positive electrode sheet or the negative electrode sheet by emitting a laser beam, and the target length of the laser mark in the first image and the standard length can be used to detect whether the accuracy of the image acquisition device has deteriorated during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell electrode sheet alignment detection results.

[0227] In some embodiments, performing accuracy detection of the image acquisition device based on the standard length and the target length may include:

[0228] When the difference between the standard length and the target length is greater than a preset third threshold, it is determined that the accuracy of the image acquisition device does not meet the accuracy requirement.

[0229] Normally, the target length of the laser mark calculated in each first image taken should be equal to the standard length. Therefore, the accuracy of the image acquisition device can be detected by the difference between the standard length and the target length. When the difference between the standard length and the target length is greater than a preset third threshold, it can be considered that the first image is distorted, that is, at this time, it can be considered that the accuracy of the image acquisition device does not meet the accuracy requirement. Among them, the preset third threshold can be set according to actual experience.

[0230] In this way, the difference between the target length of the laser mark and the standard length can be used to detect whether the accuracy of the image acquisition device deteriorates during the entire process of battery cell winding, which may cause the first image to be distorted. This can prevent the image acquisition device from being fooled and improve the reliability of the battery cell pole piece alignment detection results.

[0231] In some embodiments, the method may further include:

[0232] When the accuracy of the image acquisition device does not meet the accuracy requirement, a second warning message is output.

[0233] In this way, the second warning information can be output when the accuracy of the image acquisition device does not meet the accuracy requirement, so that the operator can adjust the parameters of the image acquisition device according to the second warning information to improve the accuracy of the image acquisition device.

[0234] Aspects of the present disclosure are described above with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and program products according to the embodiments of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by a computer program or instruction. These programs or instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the functions / actions specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0235] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A detection system for the alignment of battery cell pole pieces, characterized in that: include: A winding machine, comprising a winding roller, for winding a battery cell, wherein the battery cell comprises a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet is provided with a plurality of positive electrode tabs, and the head and tail of the positive electrode sheet are both provided with insulating parts along the extension direction of the positive electrode tabs, wherein, in the extension direction of the positive electrode tabs, the positive electrode tabs are at a first distance from the positive electrode sheet, and the insulating parts are at a second distance from the positive electrode sheet; an image acquisition device, arranged on a winding roller facing the winding machine, for capturing a first image of the positive electrode sheet and the negative electrode sheet being wound onto the winding roller during the winding process of the battery cell, wherein the first image includes the negative electrode sheet and the positive electrode tab and the insulating portion protruding from the negative electrode sheet along the extension direction of the positive electrode tab; a processor, communicatively connected to the image acquisition device, for determining, according to the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab; and performing a cell electrode sheet alignment detection based on the first distance, the second distance, the third distance and the fourth distance; The detecting of the alignment of the battery cell pole pieces based on the first distance, the second distance, the third distance and the fourth distance includes: determining a first difference between the first distance and the third distance, and a second difference between the second distance and the fourth distance; When the first difference is smaller than a preset first threshold, or the second difference is smaller than the first threshold, it is determined that the alignment of the battery cell pole pieces does not meet the qualified alignment condition.

2. The system according to claim 1, characterized in that The image acquisition device comprises: A camera, connected to the winding roller via a bracket, with a field of view of the camera facing the winding roller, for capturing a first image of the battery cell being wound on the winding roller; A light source is disposed between the camera and the winding roller, and the light of the light source is directed toward the battery core.

3. The system according to claim 1, characterized in that The system further comprises: A material unloading mechanism is arranged downstream of the winding machine, and is used to place the battery cells whose battery cell electrode sheet alignment does not meet the qualified alignment conditions to the position of the unqualified battery cells.

4. The system according to claim 1, characterized in that The system further comprises: A laser emitting device, disposed on a side of the image acquisition device away from the winding roller, for emitting a laser beam to the positive electrode sheet or the negative electrode sheet to display a laser mark of a standard length on the positive electrode sheet or the negative electrode sheet; The processor is further configured to: Determining a target length of the laser mark according to the first image with the laser mark captured by the image acquisition device; The accuracy of the image acquisition device is detected based on the standard length and the target length.

5. The system according to claim 1, characterized in that The processor is further configured to: Determine, according to the first image, a fifth distance between at least three target electrode tabs and the positive electrode sheet, wherein the at least three target electrode tabs include at least one positive electrode tab located in a head region of the positive electrode sheet, at least one positive electrode tab located in a tail region of the positive electrode sheet, and at least one positive electrode tab located in a middle region of the positive electrode sheet; The accuracy of the image acquisition device is detected based on the fifth distance.

6. A method for detecting the alignment of a battery cell electrode, characterized in that: Applied to the system according to any one of claims 1 to 5, the method comprises: Acquire a first image in which a positive electrode sheet and a negative electrode sheet have been wound onto a winding roller of a winding machine during a battery cell winding process, wherein the battery cell comprises the positive electrode sheet and the negative electrode sheet, the positive electrode sheet is provided with a plurality of positive electrode tabs, and the head and tail of the positive electrode sheet are both provided with insulating portions along the extension direction of the positive electrode tabs, wherein, in the extension direction of the positive electrode tabs, there is a first distance between the positive electrode tabs and the positive electrode sheet, and there is a second distance between the insulating portion and the positive electrode sheet, and the first image comprises the negative electrode sheet and the positive electrode tab and the insulating portion protruding from the negative electrode sheet along the extension direction of the positive electrode tabs; Determine, according to the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet, in the extension direction of the positive electrode tab; Performing cell pole piece alignment detection based on the first distance, the second distance, the third distance and the fourth distance; The detecting of the alignment of the battery cell pole pieces based on the first distance, the second distance, the third distance and the fourth distance includes: determining a first difference between the first distance and the third distance, and a second difference between the second distance and the fourth distance; When the first difference is smaller than a preset first threshold, or the second difference is smaller than the first threshold, it is determined that the alignment of the battery cell pole pieces does not meet the qualified alignment condition.

7. The method according to claim 6, characterized in that Determining, according to the first image, a third distance between the positive electrode tab and the negative electrode sheet, and a fourth distance between the insulating portion and the negative electrode sheet in the extension direction of the positive electrode tab, comprises: Extracting the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode sheet from the first image; Determining a third distance between the positive electrode tab and the negative electrode sheet according to an edge line of the positive electrode tab and an edge line of the negative electrode sheet; A fourth distance between the insulating portion and the negative electrode sheet is determined according to an edge line of the insulating portion and an edge line of the negative electrode sheet.

8. The method according to claim 7, characterized in that The step of extracting the edge line of the positive electrode tab, the edge line of the insulating portion, and the edge line of the negative electrode sheet from the first image includes: determining a region of interest in the first image; According to the region of interest, determining a pole lug region, an insulating portion region, and a pole piece region in the first image; The tab region, the insulating portion region and the pole piece region are subjected to edge grabbing processing to obtain edge lines of the positive tab, edge lines of the insulating portion and edge lines of the negative pole piece.

9. The method according to claim 6, characterized in that After the cell electrode alignment detection is performed based on the first distance, the second distance, the third distance, and the fourth distance, the method further includes: When the alignment of the battery cell pole pieces does not meet the qualified alignment condition, a first warning message is output.

10. The method according to claim 6, characterized in that After the cell electrode alignment detection is performed based on the first distance, the second distance, the third distance, and the fourth distance, the method further includes: When the alignment of the electrode sheets of the battery cell does not meet the qualified alignment condition, the unloading mechanism is controlled to place the battery cell at the position of the unqualified battery cell.

11. The method according to claim 6, characterized in that The method further comprises: Determine, according to the first image, a fifth distance between at least three target electrode tabs and the positive electrode sheet, wherein the at least three target electrode tabs include at least one positive electrode tab located in a head region of the positive electrode sheet, at least one positive electrode tab located in a tail region of the positive electrode sheet, and at least one positive electrode tab located in a middle region of the positive electrode sheet; The accuracy of the image acquisition device is detected based on the fifth distance.

12. The method according to claim 11, characterized in that When the number of the target electrode tabs is three, the target electrode tabs include the first positive electrode tab, the last positive electrode tab and the middle electrode tab among the plurality of positive electrode tabs; Among them, the difference between the first number of spaced-apart pole tabs and the second number of spaced-apart pole tabs is less than or equal to 1, the first number of spaced-apart pole tabs is the number of spaced-apart pole tabs between the first positive pole tab and the middle pole tab, and the second number of spaced-apart pole tabs is the number of spaced-apart pole tabs between the last positive pole tab and the middle pole tab.

13. The method according to claim 11, characterized in that The performing accuracy detection of the image acquisition device based on the fifth distance includes: Determining a third difference corresponding to any two target tabs according to a fifth distance between the at least three target tabs and the positive electrode sheet; The accuracy of the image acquisition device is detected based on the third difference value corresponding to the arbitrary two target tabs.

14. The method according to claim 13, characterized in that The accuracy detection of the image acquisition device based on the third difference corresponding to the arbitrary two target tabs includes: When any third difference between the third differences corresponding to the arbitrary two target tabs is greater than a preset second threshold, determining that the accuracy of the image acquisition device does not meet the accuracy requirement; The second threshold is a critical value of the third difference between any two target tabs when the accuracy of the image acquisition device does not meet the accuracy requirement.

15. The method according to claim 13, characterized in that The accuracy detection of the image acquisition device based on the third difference corresponding to the arbitrary two target tabs includes: Determining a maximum value of the third difference from the third difference values ​​corresponding to the arbitrary two target tabs; When the maximum value of the third difference is greater than a preset second threshold, determining that the accuracy of the image acquisition device does not meet the accuracy requirement; The second threshold is a critical value of the third difference between any two target tabs when the accuracy of the image acquisition device does not meet the accuracy requirement.

16. The method according to claim 6, characterized in that The method further comprises: Acquire a first image with a laser mark during the winding process of the battery cell, wherein the laser mark is a laser mark of a standard length displayed on the positive electrode sheet or the negative electrode sheet by emitting a laser beam from a laser emitting device; Determining a target length of the laser mark according to the first image with the laser mark; The accuracy of the image acquisition device is detected based on the standard length and the target length.

17. The method according to claim 16, characterized in that The accuracy detection of the image acquisition device based on the standard length and the target length includes: When the difference between the standard length and the target length is greater than a preset third threshold, it is determined that the accuracy of the image acquisition device does not meet the accuracy requirement.

18. The method according to any one of claims 11 to 17, characterized in that The method further comprises: When the accuracy of the image acquisition device does not meet the accuracy requirement, a second warning message is output.

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