Method and device for improving winding and coating quality of battery cell

Abstract

The invention discloses a method and a device for improving the winding and coating quality of a battery cell. The method comprises the following steps: acquiring a plurality of battery cell images in a battery cell winding process; performing defect detection on the battery cell according to the obtained battery cell image; and judging the wrapping quality of the battery cell winding according to a detection result of the defect detection. According to the invention, the battery cell picture collected in the battery cell winding process is detected through an image recognition means, so that poor coated products such as loose cores and black cores can be rejected in time, and the quality level of output qualified products is improved.

Description

Technical Field

[0001] This invention relates to the field of intelligent lithium battery equipment, and more specifically to a method and apparatus for improving the quality of battery cell winding and coating. Background Art

[0002] Quality control of the coating process in the cell winding process is one of the core technical indicators of power battery manufacturing. The winding and coating quality of the cell directly affects the energy density, cycle life and safety performance of the battery.

[0003] When the coating quality is substandard, the battery will have multiple safety hazards. For example, uneven coating of the cell may lead to uneven stress distribution inside the cell, which will affect the formation and stability of the SEI film during charging and discharging, resulting in core pulling defects; or if the relative offset between the separator and the electrode is too large during the coating process, the cell may form a black ring on the surface of the coating layer after it is pressed to a fixed height after winding, which is the black core defect.

[0004] Both core-pulling defects and black core defects are instances of substandard coating precision that may occur during the battery cell coating process, resulting in defective coated cells. If these defective coated cells are not promptly screened and removed, they may not only lead to wasted production capacity when entering the module assembly stage, but may also pose safety hazards such as expansion and deformation, lithium plating, and short circuits during charge and discharge cycles. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a method and apparatus for improving the quality of battery cell winding and coating.

[0006] The first aspect of this invention provides a method for improving the quality of battery cell winding and coating, comprising the following steps:

[0007] Multiple images of the battery cell are acquired during the cell winding process;

[0008] Defect detection of the battery cell is performed based on the acquired battery cell images;

[0009] The quality of the cell winding is determined based on the detection results of the defect detection.

[0010] Furthermore, the battery cell image is specifically acquired using a grayscale area array camera in conjunction with a brightness enhancement light source.

[0011] Furthermore, the defect detection of the battery cell based on the acquired cell image specifically includes the following steps:

[0012] Calculate the protrusion value of the cell end face; when the protrusion value of the cell end face is not within the preset protrusion value range, it is determined that the cell has a core-pulling defect;

[0013] Calculate the relative offset distance between the cell separator and the electrode; when the relative distance between the cell separator and the electrode is not within the preset relative offset distance range, it is determined that the cell has a black core defect.

[0014] Furthermore, the calculation of the protrusion value of the cell end face specifically includes the following steps:

[0015] The battery cell image is segmented to obtain a battery cell region and a raised region; wherein, the battery cell region represents the outermost covering region of the battery cell; the raised region represents the protruding part of the inner covering region of the battery cell relative to the outermost covering region;

[0016] The relative distance between the protruding area and the cell area is calculated to obtain the protrusion value of the cell end face.

[0017] Further, the process of segmenting the battery cell image to obtain the battery cell region and the protrusion region specifically includes the following steps:

[0018] The processing area of ​​the battery cell image is determined as the first region;

[0019] The first region is opened using a rectangular structuring element to obtain the second region.

[0020] By performing connectivity processing on the second region, a third region is obtained;

[0021] Based on the preset cell conditions, the third region is filtered to obtain the fourth region as the cell region.

[0022] Calculate the region height of the fourth region;

[0023] Based on the region height of the fourth region, an opening operation is performed on the fourth region using a rectangular structuring element to obtain the fifth region;

[0024] Subtracting the fifth region from the fourth region yields the sixth region;

[0025] The seventh region is obtained by performing an opening operation on the sixth region using a rectangular structuring element.

[0026] By performing connectivity processing on the seventh region, the eighth region is obtained;

[0027] Based on the preset protrusion conditions, the eighth region is filtered to obtain the ninth region as the protrusion region.

[0028] Furthermore, the calculation of the relative offset distance between the cell separator and the electrode specifically includes the following steps:

[0029] Obtain the separator line segment, positive electrode line segment, and negative electrode line segment from the cell image;

[0030] In the membrane segment, the positive electrode segment, and the negative electrode segment, the midpoint column coordinates of the membrane, the positive electrode segment, and the negative electrode segment are obtained respectively.

[0031] By subtracting the midpoint column coordinates of the separator from the midpoint column coordinates of the positive electrode and the midpoint column coordinates of the negative electrode, the relative offset distances between the positive electrode and the separator and between the negative electrode and the separator are obtained, which are used as the relative offset distances between the separator and the electrode in the cell.

[0032] Further, obtaining the midpoint column coordinates of the separator, the positive electrode plate, and the negative electrode plate in the separator segment, positive electrode plate segment, and negative electrode plate segment respectively includes the following steps:

[0033] Obtain the preset widths of the separator, positive electrode, and negative electrode;

[0034] By proportionally extrapolating the preset widths of the separator, positive electrode, and negative electrode to the line segments of the separator, positive electrode, and negative electrode respectively, the coordinates of the midpoints of the separator, positive electrode, and negative electrode are obtained.

[0035] Furthermore, determining the coating quality of the battery cell winding based on the defect detection results specifically includes the following steps:

[0036] For the same target cell, if all cell images acquired during the winding process show no defects, the coating quality of the target cell is deemed to be qualified.

[0037] If any image of the target battery cell obtained during the winding process has a defect, the coating quality of the target battery cell is deemed unqualified.

[0038] The second aspect of this invention discloses an apparatus for improving the quality of battery cell winding and coating, comprising a grayscale area array camera, a brightness enhancement light source, an industrial control computer, and acceptance equipment;

[0039] The grayscale area array camera and the brightness enhancement light source are used to acquire multiple images of the battery cell during the cell winding process;

[0040] The industrial control computer is used to perform defect detection on the battery cells based on the acquired battery cell images;

[0041] The acceptance equipment is used to determine the coating quality of the battery cell winding based on the detection results of the defect detection.

[0042] Furthermore, the acceptance equipment rejects the target battery cell when it determines that the coating quality of the target battery cell is unqualified; and retains the target battery cell when it determines that the coating quality of the target battery cell is qualified.

[0043] The embodiments of the present invention have the following beneficial effects: The present invention provides a method and apparatus for improving the quality of battery cell winding and coating. By using image recognition to detect battery cell images collected during the battery cell winding process, defective products such as pulled cores and black cores can be promptly removed, thereby improving the quality level of the output qualified products.

[0044] Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the basic steps of a method for improving the winding and coating quality of battery cells according to the present invention;

[0047] Figure 2 This is a normal end face view during the battery cell winding process;

[0048] Figure 3 This is a detailed schematic diagram illustrating the defect detection steps in a method for improving the winding and coating quality of battery cells according to the present invention.

[0049] Figure 4 This is an image showing the effect of the raised end face during the battery cell winding process;

[0050] Figure 5 This is a schematic diagram showing the determination of the cell region during the cell winding process;

[0051] Figure 6 This is a schematic diagram showing the protrusion area determined during the battery cell winding process;

[0052] Figure 7 This is a schematic diagram showing the determination of the circumscribed rectangular area during the battery cell winding process;

[0053] Figure 8 This is a schematic diagram showing the positions of the separator segment, positive electrode segment, and negative electrode segment during the cell winding process. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0055] During the battery cell winding process, the coating quality is one of the most important technical parameters of the battery cell. If the coating quality of the battery cell is poor and defective cells are not removed in time, these defective cells may pose safety hazards in subsequent production and consumption stages, affecting the use of the product.

[0056] To achieve accurate detection of defective cell coating, such as Figure 1 As shown, the first embodiment of the present invention provides a method for improving the winding and coating quality of battery cells, comprising the following steps:

[0057] S1. Acquire multiple images of the battery cell during the cell winding process;

[0058] S2. Perform defect detection on the battery cell based on the acquired battery cell images;

[0059] S3. Determine the wrapping quality of the battery cell winding based on the defect detection results.

[0060] This invention uses image recognition to detect defects in battery cells, effectively determining the coating quality of the cells and promptly identifying and removing defective products.

[0061] The implementation process of each step of this invention is described in detail below:

[0062] S1. During the cell winding process, acquire multiple images of the cell.

[0063] In this embodiment of the invention, the cell image is acquired using a grayscale area array camera in conjunction with a brightness enhancement light source. Since there may be extremely slight differences in optical reflection between the metal foil and the separator during the cell winding process, this embodiment projects non-uniform structured light of a specific wavelength onto the winding area using a multi-angled high-brightness incremental dot array light source. By utilizing the differences in the scattering characteristics of the structured light stripes on different material surfaces, the image contrast between the electrode edge and the separator interface can be significantly enhanced.

[0064] Specifically, during the continuous imaging of the high-speed rotating battery cell winding cross-section by the grayscale area array camera, when the battery cell rotates with the winding needle to the preset position, the rotary encoder triggers the light source synchronization module, causing the stroboscopic light source to release high-energy pulse light instantaneously when the battery cell moves to a fixed phase angle. Combined with the microsecond-level exposure control of the global camera, the interface of the winding layer in high-speed movement is precisely frozen, and multiple battery cell images are obtained.

[0065] The acquired battery cell images are as follows Figure 2 As shown, Figure 2The image shown is of a normal end face; images of abnormal end faces will be shown later. This invention, through a collaborative design of optical enhancement and motion synchronization, effectively overcomes imaging interference caused by dynamic jitter during the winding process and the reflective properties of the material, providing a stable and reliable visual data foundation for subsequent defect detection.

[0066] S2. Perform defect detection on the battery cell based on the acquired battery cell images.

[0067] A schematic diagram of the overall steps of defect detection is shown below. Figure 3 As shown. This invention primarily addresses the control of core-pulling and black-core defects during the battery cell winding process. This invention calculates the degree of protrusion, the offset of the positive electrode center relative to the separator center, and the offset of the negative electrode center relative to the separator, and makes judgments based on preset parameters. This improves the coating quality, promptly eliminates defective products such as core-pulling and black-core defects, and ultimately improves the quality of the output qualified products.

[0068] In this embodiment of the invention, step S2, which involves defect detection of the battery cell based on the acquired cell image, specifically includes the following steps:

[0069] S2-1. Calculate the protrusion value of the cell end face; when the protrusion value of the cell end face is not within the preset protrusion value range, it is determined that the cell has a core-pulling defect.

[0070] In this embodiment of the invention, the detection of core-pulling defects is mainly achieved by controlling the degree of protrusion of the battery cell. The effect of a protruding end face of the battery cell is as follows: Figure 4 As shown, it can be seen that it is relative to Figure 2 A protrusion appears on the left side. In this embodiment of the invention, the battery cell image is segmented to obtain the battery cell region and the protrusion region. The battery cell region represents the outermost coating area of ​​the battery cell; the protrusion region represents the protruding portion of the inner coating area relative to the outermost coating area. Next, the relative distance between the protrusion region and the battery cell region is calculated to obtain the protrusion value of the battery cell end face. Finally, the quality of the battery cell's coating is determined based on the protrusion value.

[0071] As a specific embodiment, the bulge value of the cell end face can be calculated through the following steps:

[0072] S2-1-1. Determine the processing area of ​​the battery cell image as the first region. In this embodiment of the invention, the initial region is divided by a fixed threshold segmentation method. For example, a threshold range of [25, 255] can be set to perform binarization processing on the battery cell image to achieve preliminary separation of the battery cell body from the background, and obtain the initial region as the first region.

[0073] S2-1-2. Perform an opening operation on the first region using a rectangular structuring element to obtain the second region. This embodiment of the invention uses morphological opening operations to optimize the first region. For example, a rectangular structuring element with a width of 250 pixels and a height of 2 pixels can be used to perform an opening operation on the initial region, effectively eliminating isolated noise points in the vertical direction while maintaining the main body shape, resulting in an optimized region_open as the second region.

[0074] S2-1-3. Perform connectivity processing on the second region to obtain the third region. In this embodiment of the invention, after obtaining the second region, perform region connectivity enhancement processing on it; by performing connectivity analysis on the region after the opening operation, the fragmentation problem that may exist in the same battery cell body is solved, and a complete and connected battery cell region region_conn is formed as the third region.

[0075] S2-1-4. The third region is filtered according to preset cell conditions to obtain a fourth region as the cell region. After obtaining the third region, this embodiment of the invention performs region filtering based on preset geometric parameters to obtain a fourth region as the cell region. A schematic diagram of the cell region is shown below. Figure 5 As shown.

[0076] For example, the following filtering conditions can be set to filter the target area based on the standard size and imaging ratio of the battery cell product:

[0077] Width range: 280 pixels ≤ width ≤ 360 pixels;

[0078] Vertical center position: 700 pixels ≤ row ≤ 820 pixels;

[0079] Horizontal center position: 700 pixels ≤ column ≤ 900 pixels;

[0080] The effective region of the target battery cell is accurately extracted by constraining the parameters mentioned above, and is denoted as region_selected.

[0081] S2-1-5. Calculate the region height of the fourth region. After obtaining the cell region, this embodiment of the invention divides the cell region into raised regions. First, the region height curr_h of the cell region region_selected is calculated.

[0082] S2-1-6. Based on the region height of the fourth region, perform an opening operation on the fourth region using a rectangular structuring element to obtain the fifth region. In this embodiment of the invention, the size of a matching rectangular structuring element is generated by calculating the determined cell region height curr_h. An exemplary value is 30 pixels wide × 0.8·curr_h high. This parameter design can effectively maintain the main structural features of the cell while separating abnormal protrusions; finally, a stable main region region_open1 is obtained as the fifth region through a morphological opening operation.

[0083] S2-1-7. Subtract the fifth region from the fourth region to obtain the sixth region. After obtaining the fifth region, this embodiment of the invention performs a region difference operation (region_selected-region_open1) to obtain the potential convex region region_diff as the sixth region.

[0084] S2-1-8. Perform an opening operation on the sixth region using a rectangular structuring element to obtain the seventh region. After obtaining the sixth region, this embodiment of the invention further performs microstructure optimization processing. Specifically, a rectangular structuring element with a width of 6 pixels and a height of 1 pixel is used to perform a second opening operation on region_diff to eliminate minor noise interference and generate a clear candidate region for raised features, region_open2, as the seventh region.

[0085] S2-1-9. Perform connectivity processing on the seventh region to obtain the eighth region. After obtaining the seventh region, this embodiment of the invention performs connectivity analysis on the optimized region to obtain a fully connected convex region region_conn1 as the eighth region.

[0086] S2-1-10. Based on the preset protrusion conditions, the eighth region is filtered to obtain the ninth region as the protruding region. Finally, according to the actual production standard, the embodiment of the present invention sets an area threshold (Area>30 pixels in this invention) and confirms the effective protruding region region_selected1 as the ninth region. A schematic diagram of the protruding region is shown below. Figure 6 As shown.

[0087] After obtaining the cell region and the protrusion region through the above steps, the geometric parameters of the confirmed protrusion region are analyzed: by obtaining the minimum bounding rectangle region_trans of the protrusion feature, specifically as follows... Figure 7 As shown. In order to obtain a quantitative judgment index that can stably reflect the size characteristics of the protrusion, the embodiment of the present invention uses the horizontal projection width value w_value of the circumscribed rectangle as the final protrusion value.

[0088] Finally, the process allowable range [min, max] is set. When the obtained bulge value satisfies min≤w_value≤max, the cell image is judged as qualified (OK). If it exceeds the set range, it is judged as defective (NG). The threshold parameter is calibrated according to the design specifications and historical test data.

[0089] S2-2. Calculate the relative offset distance between the cell separator and the electrode; when the relative distance between the cell separator and the electrode is not within the preset relative offset distance range, it is determined that the cell has a black core defect.

[0090] In this embodiment of the invention, the detection of black core defects is mainly achieved by controlling the relative offset between the cell separator and the center of the electrode. Specifically, step S2-2 calculates the relative offset distance between the cell separator and the electrode, which includes the following steps:

[0091] S2-2-1. Obtain the separator line segment, positive electrode line segment, and negative electrode line segment from the cell image.

[0092] This invention employs image recognition technology to obtain the characteristic edge lines of a multi-layered battery cell structure, including:

[0093] Diaphragm segments: left boundary line (film_left) and right boundary line (film_right);

[0094] Positive electrode segment: left effective boundary line (pole_posi_left) and right effective boundary line (pole_posi_right);

[0095] Negative electrode segment: left effective boundary line (pole_nega_left) and right effective boundary line (pole_nega_right).

[0096] The positions of each line segment are as follows Figure 8 As shown.

[0097] S2-2-2. In the membrane segment, positive electrode segment, and negative electrode segment, obtain the midpoint column coordinates of the membrane, the positive electrode segment, and the negative electrode segment, respectively.

[0098] When calculating the coordinates of the midpoint column, it is first necessary to determine the diaphragm reference datum. In this embodiment of the invention, the coordinate values ​​of the central axis of the left and right boundary lines, column_film, are calculated as the spatial alignment datum for the multilayer structure.

[0099] After obtaining the reference benchmark, the coordinates of the midpoint column of the positive electrode are first calculated. In this embodiment of the invention, a dynamic feature compensation mechanism is adopted for the positive electrode: when there is imaging shadow interference on one side of the positive electrode line segment, the theoretical central axis coordinate value column_posi can be calculated based on the known standard width parameter w_posi of the positive electrode and the coordinate values ​​of the left / right effective boundary lines using the formula column_posi = pole_posi_left + w_posi. In the undisturbed state, the central axis coordinate values ​​column_posi of the left and right effective boundary lines can be calculated directly.

[0100] Then, the midpoint column coordinates of the negative electrode are calculated. In this embodiment of the invention, a standard centerline detection method is used for the negative electrode to directly calculate the coordinates of the central axis between the left and right effective boundary lines (column_nega). Alternatively, the same dynamic feature compensation mechanism as that used for the positive electrode midpoint column coordinates can be used to calculate the midpoint column coordinates of the negative electrode.

[0101] S2-2-3. By subtracting the midpoint column coordinates of the separator from the midpoint column coordinates of the positive electrode and the midpoint column coordinates of the negative electrode, the relative offset distances between the positive electrode and the separator and between the negative electrode and the separator are obtained, which are used as the relative offset distances between the separator and the electrode in the cell.

[0102] Specifically, in this embodiment of the invention, a relative displacement parameter system is first established, and the relative offset distance between the positive and negative electrodes is calculated using the following formula:

[0103] The relative offset distance of the positive electrode is: off_value1 = |column_posi - column_film|;

[0104] The relative offset distance of the negative electrode: off_value2 = |column_nega - column_film|.

[0105] After calculating the relative offset distance, this embodiment of the invention normalizes the calculated offset and converts it into a physical displacement in the product specification coordinate system.

[0106] Finally, a threshold range [T_min, T_max] is set according to the cell packaging process specifications. This range can be determined based on parameters such as the allowable tolerance range of the cell material's thermal expansion coefficient and the repeatability accuracy of the equipment's mechanical positioning. Automatic judgment conditions are then executed based on the set threshold range.

[0107] It is considered qualified (marked as OK) if and only if off_value1∈[T_min,T_max] and off_value2∈[T_min,T_max];

[0108] If any parameter exceeds the threshold range, the product is judged as defective (marked as NG).

[0109] S3. Determine the wrapping quality of the battery cell winding based on the defect detection results.

[0110] In this embodiment of the invention, in step S3, for the same target battery cell, the coating quality of the target battery cell is judged to be qualified only if all battery cell images obtained during the winding process are free of defects; if any battery cell image obtained during the winding process is defective, the coating quality of the target battery cell is directly judged to be unqualified.

[0111] Based on the above defect identification method, the embodiments of the present invention can effectively improve the coating quality of battery cell winding, promptly remove defective products such as core pulling, black core, and poor coating, thereby improving the quality of the output qualified products.

[0112] The second embodiment of the present invention discloses an apparatus for improving the winding and coating quality of battery cells, including a grayscale area array camera, a brightness enhancement light source, an industrial control computer, and acceptance equipment;

[0113] A grayscale area array camera and a brightness enhancement light source are used to acquire multiple images of the battery cell during the cell winding process;

[0114] The industrial computer is used to perform defect detection on the battery cells based on the acquired battery cell images;

[0115] Acceptance equipment is used to determine the coating quality of battery cell winding based on the results of defect detection.

[0116] Specifically, if the acceptance equipment determines that the coating quality of the target battery cell is unqualified, the target battery cell will be rejected; if the coating quality of the target battery cell is qualified, the target battery cell will be retained.

[0117] The methods described in the first embodiment of the present invention are all applicable to the device embodiment. The specific functions implemented in the device embodiment are the same as those in the above method embodiment, and the beneficial effects achieved are also the same as those achieved by the above method.

[0118] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present invention are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0119] Those skilled in the art will understand that modules in the device of the embodiments of the present invention can be adaptively modified and placed in one or more devices different from those embodiments. Modules, units, or components in the embodiments of the present invention can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the corresponding claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the corresponding claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0120] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0121] Furthermore, the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. In particular, for embodiments such as apparatus and devices, since they are basically similar to the method embodiments, the relevant parts can be referred to the description of the method embodiments. The apparatus, devices, and other embodiments described above are merely illustrative, and the modules, units, etc., described as separate components may or may not be physically separate, that is, they may be located in one place or distributed in multiple places, such as nodes in a system network. Specifically, some or all of the modules and units can be selected according to actual needs to achieve the purpose of the above-described embodiment solutions. Those skilled in the art can understand and implement this without creative effort.

[0122] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0123] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0124] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0125] In embodiments of the present invention, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of the present invention may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0126] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention. Other embodiments of the present invention will readily conceive of by considering the specification and practicing the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

Claims

1. A method for improving the quality of battery cell winding and coating, characterized in that, Includes the following steps: Multiple images of the battery cell are acquired during the cell winding process; Defect detection of the battery cell is performed based on the acquired battery cell images; The quality of the cell winding is determined based on the detection results of the defect detection.

2. The method for improving the winding and coating quality of battery cells according to claim 1, characterized in that, The battery cell image is specifically acquired using a grayscale area array camera in conjunction with a brightness enhancement light source.

3. The method for improving the winding and coating quality of battery cells according to claim 1, characterized in that, The defect detection of the battery cell based on the acquired battery cell image specifically includes the following steps: Calculate the protrusion value of the cell end face; when the protrusion value of the cell end face is not within the preset protrusion value range, it is determined that the cell has a core-pulling defect; Calculate the relative offset distance between the cell separator and the electrode; when the relative distance between the cell separator and the electrode is not within the preset relative offset distance range, it is determined that the cell has a black core defect.

4. The method for improving the winding and coating quality of battery cells according to claim 3, characterized in that, The calculation of the protrusion value on the end face of the battery cell specifically includes the following steps: The battery cell image is segmented to obtain a battery cell region and a raised region; wherein, the battery cell region represents the outermost covering region of the battery cell; the raised region represents the protruding part of the inner covering region of the battery cell relative to the outermost covering region; The relative distance between the protruding area and the cell area is calculated to obtain the protrusion value of the cell end face.

5. A method for improving the quality of battery cell winding and coating according to claim 4, characterized in that, The process of segmenting the battery cell image to obtain the battery cell region and the protrusion region specifically includes the following steps: The processing area of ​​the battery cell image is determined as the first region; The first region is opened using a rectangular structuring element to obtain the second region. By performing connectivity processing on the second region, a third region is obtained; Based on the preset cell conditions, the third region is filtered to obtain the fourth region as the cell region. Calculate the region height of the fourth region; Based on the region height of the fourth region, an opening operation is performed on the fourth region using a rectangular structuring element to obtain the fifth region; Subtracting the fifth region from the fourth region yields the sixth region; The seventh region is obtained by performing an opening operation on the sixth region using a rectangular structuring element. By performing connectivity processing on the seventh region, the eighth region is obtained; Based on the preset protrusion conditions, the eighth region is filtered to obtain the ninth region as the protrusion region.

6. The method for improving the winding and coating quality of battery cells according to claim 3, characterized in that, The calculation of the relative offset distance between the cell separator and the electrode plate specifically includes the following steps: Obtain the separator line segment, positive electrode line segment, and negative electrode line segment from the cell image; In the membrane segment, the positive electrode segment, and the negative electrode segment, the midpoint column coordinates of the membrane, the positive electrode segment, and the negative electrode segment are obtained respectively. By subtracting the midpoint column coordinates of the separator from the midpoint column coordinates of the positive electrode and the midpoint column coordinates of the negative electrode, the relative offset distances between the positive electrode and the separator and between the negative electrode and the separator are obtained, which are used as the relative offset distances between the separator and the electrode in the cell.

7. The method for improving the winding and coating quality of battery cells according to claim 6, characterized in that, The step of obtaining the midpoint column coordinates of the separator, the positive electrode plate, and the negative electrode plate in the separator segment, the positive electrode plate segment, and the negative electrode plate segment, respectively, specifically includes the following steps: Obtain the preset widths of the separator, positive electrode, and negative electrode; By proportionally extrapolating the preset widths of the separator, positive electrode, and negative electrode to the line segments of the separator, positive electrode, and negative electrode respectively, the coordinates of the midpoints of the separator, positive electrode, and negative electrode are obtained.

8. The method for improving the winding and coating quality of battery cells according to claim 1, characterized in that, The determination of the cell winding coating quality based on the defect detection results specifically includes the following steps: For the same target cell, if all cell images acquired during the winding process show no defects, the coating quality of the target cell is deemed to be qualified. If any image of the target battery cell obtained during the winding process has a defect, the coating quality of the target battery cell is deemed unqualified.

9. An apparatus for improving the quality of battery cell winding and coating, characterized in that, This includes a grayscale area scan camera, a brightness enhancement light source, an industrial control computer, and acceptance equipment; The grayscale area array camera and the brightness enhancement light source are used to acquire multiple images of the battery cell during the cell winding process; The industrial control computer is used to perform defect detection on the battery cells based on the acquired battery cell images; The acceptance equipment is used to determine the coating quality of the battery cell winding based on the detection results of the defect detection.

10. The apparatus for improving the winding and coating quality of battery cells according to claim 9, characterized in that, The acceptance equipment rejects the target battery cell when it determines that the coating quality is unqualified; and retains the target battery cell when it determines that the coating quality is qualified.

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