A method for detecting defects in adhesive wires

Abstract

The present application discloses a method for detecting glue line defects, including: obtaining an image of an electric core and positioning the position of the skirt of the electric core; identifying the glue line of the electric core and calculating the distance from the glue line to the skirt of the electric core and the glue width of the glue line; judging whether there are defects in the glue line according to the distance from the glue line to the skirt of the electric core and the glue width of the glue line; judging whether there are defects in the glue line through the glue width of the glue line and the distance from the glue line to the skirt of the electric core, avoiding the use of electric cores with poor glue application quality at the glue application station caused by factors such as deviation in the moving position of the slide rail, deviation in the moving position of the glue dispensing head, and deviation in visual positioning, and improving the yield and service performance of the electric cores.

Description

Technical Field

[0001] This application relates to the technical field of defect detection, and particularly to a method for detecting glue line defects. Background Art

[0002] After the battery cell moves to the dispensing position on the profiling jig and completes dispensing, due to factors such as the deviation of the slide rail movement position, the deviation of the dispensing head movement, and the deviation of the visual positioning, the dispensing quality of the dispensing work point is affected, thereby affecting the yield and service performance of the battery cell. Therefore, it is necessary to detect the glue line to timely discover defective products to ensure the quality and performance of the glue line. Summary of the Invention

[0003] This application provides a method for detecting glue line defects to provide a method for detecting glue line defects to improve the yield and service performance of battery cells.

[0004] In view of this, the first aspect of this application provides a method for detecting glue line defects, including:

[0005] Obtain an image of the battery cell and locate the position of the battery cell skirt;

[0006] Identify the glue line of the battery cell and calculate the distance from the glue line to the battery cell skirt and the glue width of the glue line;

[0007] Judge whether there are defects in the glue line according to the distance from the glue line to the battery cell skirt and the glue width of the glue line.

[0008] Optionally, the obtaining of the battery cell image includes:

[0009] Take a picture of the left skirt of the battery cell from the upper left of the battery cell by the left camera to obtain a left image of the battery cell;

[0010] Take a picture of the right skirt of the battery cell from the upper right of the battery cell by the right camera to obtain a right image of the battery cell, wherein there is an overlapping area in the fields of view of the left camera and the right camera;

[0011] Use the left image of the battery cell and the right image of the battery cell as the battery cell image, or splice the left image of the battery cell and the right image of the battery cell to obtain a spliced image, and use the spliced image as the battery cell image.

[0012] Optionally, the positioning of the position of the battery cell skirt includes:

[0013] Extract the head edge line, tail edge line and side edge line of the battery cell skirt from the battery cell image;

[0014] Calculate the intersection points of the head edge line, tail edge line and side edge line of the battery cell skirt to obtain the position of the battery cell skirt.

[0015] Optionally, the identification of the glue line of the battery cell includes:

[0016] Determine the head area and the tail area of the glue line according to the intersection points of the head edge line, the tail edge line and the side edge line of the cell skirt respectively;

[0017] Obtain the centroid position of the head according to the head area of the glue line, and determine the head position of the glue line according to the head area of the glue line and the centroid position of the head;

[0018] Obtain the centroid position of the tail according to the tail area of the glue line, and determine the tail position of the glue line according to the tail area of the glue line and the centroid position of the tail.

[0019] Optionally, the method further includes:

[0020] Fit a straight line based on the centroid position of the head, obtain the intersection point of the straight line and the head edge line of the cell skirt, and calculate the distance between the head position of the glue line and the intersection point to obtain the distance between the head of the glue line and the head of the cell skirt;

[0021] Detect the starting position of the glue dropping based on the distance between the head of the glue line and the head of the cell skirt.

[0022] Optionally, the calculating the distance between the glue line and the cell skirt and the glue width of the glue line includes:

[0023] Set the search range of the caliper tool, and set the starting position and the ending position of the caliper tool in the cell image according to the head position and the tail position of the glue line;

[0024] Traverse the glue line from the starting position to the ending position through the caliper tool, and obtain the distances from the upper edge and the lower edge of the traversed glue line to the side of the cell skirt and the glue width of the glue line.

[0025] Optionally, when the cell image is the spliced image, the setting the starting position and the ending position of the caliper tool in the cell image according to the head position and the tail position of the glue line includes:

[0026] Use the head position of the glue line as the starting position and the tail position as the ending position;

[0027] Or, use the tail position of the glue line as the starting position and the head position as the ending position.

[0028] Optionally, when the cell image includes the left cell image and the right cell image, the setting the starting position and the ending position of the caliper tool in the cell image according to the head position and the tail position of the glue line includes:

[0029] For the left side image of the battery cell, the head position of the glue line is used as the starting position, and the intersection of the glue line and the image edge of the left side image of the battery cell is used as the ending position;

[0030] For the right side image of the battery cell, the tail position of the glue line is used as the starting position, and the intersection of the glue line and the image edge of the right side image of the battery cell is used as the ending position.

[0031] Optionally, the method further includes:

[0032] The left and right cameras are calibrated using a calibration block. The left and right sides of the calibration block are engraved with horizontal and vertical laser lines. The laser lines are used to determine the field of view orientation and field of view image clarity of the left and right cameras.

[0033] Optionally, the stitching the left side image of the battery cell and the right side image of the battery cell to obtain a stitched image includes:

[0034] Obtaining a mapping relationship between the image coordinate systems of the left camera and the right camera and the world coordinate system based on a calibration result obtained by calibrating the left camera and the right camera according to the calibration block;

[0035] According to the mapping relationship between the image coordinate systems of the left camera and the right camera and the world coordinate system, the left image of the battery cell and the right image of the battery cell are respectively mapped to the world coordinate system for image stitching to obtain a stitched image.

[0036] It can be seen from the above technical solutions that this application has the following advantages:

[0037] The present application provides a method for detecting glue line defects, including: obtaining a battery cell image and locating the position of the battery cell skirt; identifying the glue line of the battery cell and calculating the distance from the glue line to the battery cell skirt and the glue width of the glue line; judging whether the glue line has defects based on the distance from the glue line to the battery cell skirt and the glue width of the glue line.

[0038] In this application, after the glue dispensing of the battery cell is completed, the battery cell image is collected, and the glue width of the glue line and the distance from the glue line to the battery cell skirt are obtained by analyzing and processing the battery cell image. Then, the glue width of the glue line and the distance from the glue line to the battery cell skirt are used to judge whether there are defects in the glue line, thereby avoiding the use of battery cells with poor glue dispensing quality at the glue dispensing station due to factors such as slide rail movement deviation, glue dispensing head movement deviation, and visual positioning deviation, thereby improving the yield and performance of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0040] Figure 1 It is a schematic flowchart of a method for detecting glue line defects provided by an embodiment of the present application;

[0041] Figure 2 It is a schematic diagram of the installation of left and right cameras provided by an embodiment of the present application;

[0042] Figure 3 It is a schematic structural diagram of a calibration block provided by an embodiment of the present application;

[0043] Figure 4 It is a schematic diagram of the relationship between the calibration block and the battery cell provided by an embodiment of the present application;

[0044] Figure 5 It is a schematic diagram of the head target area in the left-side image of the battery cell provided by an embodiment of the present application;

[0045] Figure 6 It is a schematic diagram of the glue line head area in the left-side image of the battery cell provided by an embodiment of the present application;

[0046] Figure 7 It is a schematic diagram of a straight line generated by fitting based on the centroid position of the head provided by an embodiment of the present application;

[0047] Figure 8 It is a schematic diagram of the intersection point of the straight line and the head edge line of the battery cell skirt provided by an embodiment of the present application;

[0048] Figure 9 It is a schematic diagram of the distance between the glue line head and the head of the battery cell skirt provided by an embodiment of the present application;

[0049] Figure 10 It is a schematic diagram of the starting position and the ending position of the left-side image of the battery cell provided by an embodiment of the present application;

[0050] Figure 11 It is a schematic diagram of the starting position and the ending position of the right-side image of the battery cell provided by an embodiment of the present application. Detailed implementation manners

[0051] To enable those skilled in the art to better understand the solution of this application, the following will clearly and completely describe the technical solution in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

[0052] For ease of understanding, please refer to Figure 1 , an embodiment of this application provides a method for detecting glue line defects, including:

[0053] Step 101: Obtain an image of the battery cell and locate the position of the battery cell skirt.

[0054] The battery cell image can be obtained by taking a picture of the battery cell from above with a camera. In the embodiment of this application, it is considered that it is difficult for a single camera to capture a clear and complete arc-shaped battery cell, which will affect the subsequent detection results of glue line defects. To improve this problem, two cameras are simultaneously used to take pictures of the left and right sides of the battery cell respectively. Please refer to Figure 2 the installation schematic diagrams of the two cameras provided. The left camera is located at the upper left of the battery cell, and the right camera is located at the upper right of the battery cell. Specifically, the left camera can be set on the perpendicular bisector of the line connecting the left corner point of the left skirt of the battery cell and the vertex of the battery cell skirt, and the right camera can be set on the perpendicular bisector of the line connecting the right corner point of the right skirt of the battery cell and the vertex of the battery cell skirt. In this way, the depth of field of the left camera and the right camera can be maximized, and there is an overlapping area in the fields of view of the left camera and the right camera to prevent missing the battery cell. A light source can be set above the battery cell to capture a clear glue line.

[0055] Further, after installing the left camera and the right camera, the left camera and the right camera can be calibrated. Specifically, the camera calibration can be performed through a calibration block. When using the calibration block, remove the battery cell fixture, then install the calibration block on the base, and then install the battery cell fixture. The clarity of the image of the upper camera field of view can be adjusted through the calibration block. The structural schematic diagram of the calibration block in the embodiment of this application is as shown in Figure 3 . The front view of the calibration block is triangular and fits the arc-shaped battery cell. The left view and the right view of the calibration block are both rectangular. The two hypotenuses of the triangle are the tangent lines of the battery cell skirt and the bisecting lines of the lines connecting the vertex of the battery cell skirt and the left and right corner points, as shown in Figure 4 . The bottom edge of the triangle is the contact surface between the battery cell fixture and its underlying base; the length of the calibration block is the same as the width of the battery cell. There are laser engraved lines on the left side and the right side of the calibration block. Referring to the left view and the right view in Figure 3 , the line width of the laser line is 0.1 mm. The vertical laser line (i.e., the line 1 in Figure 3 ) is for the skirt to deviate inward by 2 mm, and the horizontal laser line (i.e.,Figure 3 The line 2) in it is the center line of the connection between the vertex of the cell skirt and the left (right) corner point. When laser scribing, the center line of the laser head is perpendicular to the inclined plane. The two laser lines can be used to confirm whether the image in the camera's field of view is clear, whether it is in focus, and to confirm the orientation of the camera's field of view. Among them, the laser line in the vertical direction of the calibration block should be in the middle position of the camera's field of view. It should be noted that the specific process of camera calibration through the calibration block belongs to the prior art, and the specific calibration process will not be elaborated here.

[0056] After completing the camera calibration, the left camera can be used to capture the left skirt of the cell from the upper left of the cell to obtain the left image of the cell; the right camera can be used to capture the right skirt of the cell from the upper right of the cell to obtain the right image of the cell.

[0057] In one embodiment, the left image of the cell and the right image of the cell can be used as the cell image. During the subsequent processing, the glue line defect detection is performed on the left image of the cell and the right image of the cell respectively.

[0058] In another embodiment, in order to improve the glue line defect detection speed, the left image of the cell and the right image of the cell can be spliced to obtain a spliced image, and the spliced image is used as the cell image. Subsequently, the glue line defect detection can be directly performed on the spliced image. When splicing the left image of the cell and the right image of the cell, the mapping relationship from the image coordinate system of the left camera and the right camera to the world coordinate system can be obtained according to the calibration results obtained by calibrating the left camera and the right camera based on the calibration block; according to the mapping relationship from the image coordinate system of the left camera and the right camera to the world coordinate system, the left image of the cell and the right image of the cell are respectively mapped to the world coordinate system for image splicing to obtain a spliced image. Since there is an overlapping area in the fields of view of the left camera and the right camera, that is, there is an overlapping area between the left image of the cell captured by the left camera and the right image of the cell captured by the right camera. According to the calibration results, the left image of the cell and the right image of the cell are respectively mapped to the same world coordinate system, and then the overlapping area between the left image of the cell and the right image of the cell in the same world coordinate system can be determined. Furthermore, based on this overlapping area, the left image of the cell and the right image of the cell can be spliced to obtain a spliced image.

[0059] After obtaining the cell image, locate the position of the cell skirt from the cell image. The head edge line, tail edge line, and side edge line of the cell skirt can be extracted from the cell image; calculate the intersection points of the head edge line, tail edge line of the cell skirt and the side edge line to obtain the position of the cell skirt. In the embodiment of the present application, it is considered that the position of the cell in the camera field of view will have position fluctuations. Because the dispensing platform has mechanical positioning, the position fluctuations of the cell are within a certain range. The search area of the caliper tool can be set to cover the position fluctuation range of the cell, and then the edge straight lines are found at the head, tail, and side of the cell skirt respectively to obtain the head edge line, tail edge line, and side edge line of the cell skirt; then calculate the intersection point of the head edge line and the side edge line of the cell skirt, and the intersection point of the tail edge line and the side edge line of the cell skirt to achieve the positioning of the cell skirt.

[0060] It can be understood that when the cell image is the left cell image and the right cell image, the left cell image only contains the head of the cell skirt (i.e., the left skirt), while the tail of the cell skirt (i.e., the right skirt) is in the right cell image. When positioning the cell skirt in the left cell image and the right cell image, the head edge line and the side edge line of the cell skirt are extracted from the left cell image through the caliper tool, and the tail edge line and the side edge line of the cell skirt are extracted from the right cell image through the caliper tool. Calculate the intersection point of the head edge line and the side edge line of the cell skirt in the left cell image, and calculate the intersection point of the tail edge line and the side edge line of the cell skirt in the right cell image.

[0061] When the cell image is a spliced image after splicing the left cell image and the right cell image, there is a complete cell skirt in the spliced image. When positioning the cell skirt in the spliced image, the head edge line, tail edge line, and side edge line of the cell skirt can be extracted from the spliced image at the same time through the caliper tool, and the intersection point of the head edge line and the side edge line of the cell skirt, and the intersection point of the tail edge line and the side edge line of the cell skirt are calculated.

[0062] Step 102: Identify the glue line of the cell, and calculate the distance from the glue line to the cell skirt and the glue width of the glue line.

[0063] After obtaining the intersection point of the head edge line and the side edge line of the cell skirt and the intersection point of the tail edge line and the side edge line of the cell skirt, the position of the glue line of the cell in the cell image can be identified according to the position of the intersection point. The specific process is as follows:

[0064] Determine the glue line head area and the glue line tail area according to the intersection points of the head edge line, tail edge line of the cell skirt and the side edge line respectively;

[0065] Obtain the centroid position of the head according to the head area of the glue line, and determine the head position of the glue line according to the head area of the glue line and the centroid position of the head;

[0066] Obtain the centroid position of the tail according to the tail area of the glue line, and determine the tail position of the glue line according to the tail area of the glue line and the centroid position of the tail.

[0067] Specifically, the intersection points of the head edge line, the tail edge line and the side edge line of the cell skirt can be used as reference points respectively, and offset a first preset distance in the horizontal direction and a second preset distance in the vertical direction to obtain the head target area and the tail target area respectively; then determine the head area of the glue line in the head target area and the tail area of the glue line in the tail target area; obtain the centroid position of the head according to the head area of the glue line, and determine the head position of the glue line according to the head area of the glue line and the centroid position of the head; obtain the centroid position of the tail according to the tail area of the glue line, and determine the tail position of the glue line according to the tail area of the glue line and the centroid position of the tail.

[0068] Taking the left-side image of the cell as an example, offset a certain area based on the intersection point of the head edge line and the side edge line of the cell skirt in the left-side image of the cell to obtain the head target area as shown in Figure 5 i.e., the rectangular frame in Figure 5 ; the head area of the glue line (as shown in Figure 6 ) and the centroid position of the head area of the glue line can be determined in the head target area through the Blob tool to obtain the centroid position of the head; after the Blob tool determines the head area of the glue line, it will output the length and width of the head area of the glue line, and the head position of the head area of the glue line can be calculated according to the centroid position of the head and the length and width of the head area of the glue line, so as to obtain the head position of the glue line. It can be understood that the process of obtaining the tail position of the glue line from the right-side image of the cell is similar to the process of obtaining the head position of the glue line from the left-side image of the cell, and the specific process will not be elaborated here.

[0069] Furthermore, considering the detection requirements of the glue-dropping position, it is necessary to ensure that the glue-dropping starting position is the same each time. The distance d between the head of the glue line and the head of the cell skirt can be calculated according to the head position of the glue line. Through this distance d, the glue-dropping starting position can be detected to determine whether the glue-dropping starting positions of each cell are the same. If not, it means that the glue-dropping effect of the current cell does not meet the expected effect. Specifically, a straight line can be fitted based on the centroid position of the head (as shown in Figure 7 ), the intersection point of this straight line and the head edge line of the cell skirt is obtained (as shown in Figure 8 ), and the distance between the head position of the glue line and this intersection point is calculated to obtain the distance between the head of the glue line and the head of the cell skirt (as shown in Figure 9As shown in the figure); the starting position of the glue dripping is detected based on the distance between the head of the glue line and the head of the cell skirt. If the distance between the head of the glue line and the head of the cell skirt is equal to the preset distance, it means that the starting position of the glue dripping for this cell meets the preset requirements. If the distance between the head of the glue line and the head of the cell skirt is less than or greater than the preset distance, it means that the starting position of the glue dripping for this cell does not meet the preset requirements.

[0070] After identifying the glue line of the cell and obtaining the head position and tail position of the glue line, the glue line in the cell image can be traversed starting from the head position or the tail position to obtain the distances from the upper edge and the lower edge of the glue line to the side of the cell skirt and the glue width of the glue line. The search range of the caliper tool can be set, and the starting position and the ending position of the caliper tool are set in the cell image according to the head position and the tail position of the glue line; the glue line is traversed by the caliper tool from the starting position to the ending position, and the distances from the upper edge and the lower edge of the traversed glue line to the side of the cell skirt and the glue width of the glue line are obtained. After obtaining the head position and the tail position of the glue line, the starting position and the ending position of the caliper tool can be set according to the head position and the tail position of the glue line. The caliper tool is placed at the starting position, and the relevant parameters of the caliper tool are set according to actual needs, such as setting the search range of the caliper tool. The caliper tool will traverse from the starting position of the glue line to the ending position according to the set parameters. Each time the glue line is traversed, a section of the glue line is intercepted (reference can be made to Figure 10 , Figure 11 ), and the maximum value, the minimum value, and the median value of the distances from the upper edge and the lower edge of this section of the glue line to the side of the cell skirt and the glue width of this section of the glue line are output.

[0071] In one embodiment, when the cell image is a spliced image, the head position of the glue line can be used as the starting position and the tail position as the ending position, so that the caliper tool traverses from the head position of the glue line to the tail position of the glue line; or the tail position of the glue line can be used as the starting position and the head position as the ending position, so that the caliper tool traverses from the tail position of the glue line to the head position of the glue line.

[0072] In another embodiment, when the cell image includes the left-side image of the cell and the right-side image of the cell, for the left-side image of the cell, the head position of the glue line is used as the starting position and the intersection point of the glue line and the image edge of the left-side image of the cell is used as the ending position. Please refer to Figure 10 .

[0073] For the right-side image of the cell, the tail position of the glue line is used as the starting position and the intersection point of the glue line and the image edge of the right-side image of the cell is used as the ending position. Please refer to Figure 11 .

[0074] Step 103: Determine whether there are defects in the glue line according to the distance from the glue line to the cell skirt and the glue width of the glue line.

[0075] It is possible to determine whether there are defects in the glue line based on the distances from the upper and lower edges of the glue line to the side of the cell skirt and the glue width of the glue line. The defect categories of the glue line include broken glue, overflow glue, large-head glue, wire drawing, etc. For example, it is possible to determine whether there is broken glue in the glue line by the glue width of the glue line. If the glue width of a certain section of the glue line traversed is 0, it indicates that there is a broken glue defect in this section of the glue line; if the minimum value of the distance from the lower edge of a certain section of the glue line traversed to the side of the cell skirt is 0, or the maximum value of the distance from the lower edge of a certain section of the glue line traversed to the side of the cell skirt is greater than the preset distance threshold, it indicates that there is an overflow glue defect in this section of the glue line.

[0076] In the embodiments of the present application, after the cell is completed with dispensing, a cell image is collected, and the glue width of the glue line and the distance from the glue line to the cell skirt are obtained by analyzing and processing the cell image. Furthermore, it is determined whether there are defects such as broken glue, overflow glue, large-head glue, wire drawing, etc. in the glue line based on the glue width of the glue line and the distance from the glue line to the cell skirt, so as to avoid putting into use the cells with poor dispensing quality at the dispensing station due to factors such as the deviation of the moving position of the slide rail, the deviation of the moving of the dispensing head, the deviation of the visual positioning, etc., and improve the yield and service performance of the cells.

[0077] Terms such as "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0078] It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "And / or" is used to describe the association relationship of associated objects and indicates that three relationships can exist. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist at the same time. Among them, A and B can be singular or plural. The character " / " generally means that the associated objects before and after are in an "or" relationship. "At least one (one) of the following" or a similar expression means any combination of these items, including any combination of single item (one) or plural items (ones). For example, at least one (one) of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0079] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0080] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0081] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0082] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (English full name: Read-Only Memory, English abbreviation: ROM), random access memories (English full name: Random Access Memory, English abbreviation: RAM), magnetic disks, or optical discs that can store program codes.

[0083] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for detecting defects in adhesive wires, characterized in that, Including: Obtain an image of the battery cell and locate the position of the battery cell skirt; the locating the position of the battery cell skirt includes: Extract the head edge line, tail edge line and side edge line of the battery cell skirt from the battery cell image; Calculate the intersection points of the head edge line, tail edge line and side edge line of the battery cell skirt to obtain the position of the battery cell skirt; Identify the glue line of the battery cell according to the positions of the intersection points, and calculate the distance from the glue line to the battery cell skirt and the glue width of the glue line; the identifying the glue line of the battery cell includes: Determine the glue line head region and the glue line tail region respectively according to the intersection points of the head edge line, tail edge line and side edge line of the battery cell skirt; Obtain the head centroid position according to the glue line head region, and determine the head position of the glue line according to the glue line head region and the head centroid position; Obtain the tail centroid position according to the glue line tail region, and determine the tail position of the glue line according to the glue line tail region and the tail centroid position; Fit a straight line based on the head centroid position, obtain the intersection point of the straight line and the head edge line of the battery cell skirt, and calculate the distance between the head position of the glue line and the intersection point to obtain the distance between the head of the glue line and the head of the battery cell skirt; Detect the starting position of glue dripping based on the distance between the head of the glue line and the head of the battery cell skirt; Judge whether there is a defect in the glue line according to the distance from the glue line to the battery cell skirt and the glue width of the glue line.

2. The method for detecting glue line defects according to claim 1, wherein The obtaining the battery cell image includes: Shoot the left skirt of the battery cell from the upper left of the battery cell by the left camera to obtain the left image of the battery cell; Shoot the right skirt of the battery cell from the upper right of the battery cell by the right camera to obtain the right image of the battery cell, wherein there is an overlapping area in the fields of view of the left camera and the right camera; Use the left image of the battery cell and the right image of the battery cell as the battery cell image, or splice the left image of the battery cell and the right image of the battery cell to obtain a spliced image, and use the spliced image as the battery cell image.

3. The glue line defect detection method according to claim 2, wherein The calculating the distance from the glue line to the battery cell skirt and the glue width of the glue line includes: Set the search range of the caliper tool, and set the starting position and ending position of the caliper tool in the battery cell image according to the head position and the tail position of the glue line; Traverse the glue line from the starting position to the ending position by the caliper tool, and obtain the distances from the upper edge and the lower edge of the traversed glue line to the side of the battery cell skirt and the glue width of the glue line.

4. The method for detecting glue line defects according to claim 3, wherein, When the battery cell image is the spliced image, the setting the starting position and ending position of the caliper tool in the battery cell image according to the head position and the tail position of the glue line includes: Use the head position of the glue line as the starting position and the tail position as the ending position; Or use the tail position of the glue line as the starting position and the head position as the ending position.

5. The glue line defect detection method according to claim 3, wherein, When the battery cell image includes the left image of the battery cell and the right image of the battery cell, the setting the starting position and ending position of the caliper tool in the battery cell image according to the head position and the tail position of the glue line includes: For the left image of the battery cell, use the head position of the glue line as the starting position and the intersection point of the glue line and the image edge of the left image of the battery cell as the ending position; For the image on the right side of the battery cell, the starting position is the tail position of the glue line, and the ending position is the intersection point of the glue line and the image edge of the image on the right side of the battery cell.

6. The glue line defect detection method according to claim 2, wherein The method further includes: Calibrating the left camera and the right camera with a calibration block, where both the left side and the right side of the calibration block are engraved with laser lines in the horizontal and vertical directions, and the laser lines are used to determine the field of view orientation of the left camera and the right camera and whether the field of view images are clear.

7. The glue line defect detection method according to claim 6, wherein The step of stitching the left image and the right image of the battery cell to obtain a stitched image includes: Obtaining the mapping relationship from the image coordinate systems of the left camera and the right camera to the world coordinate system according to the calibration results obtained by calibrating the left camera and the right camera with the calibration block; Mapping the left image and the right image of the battery cell to the world coordinate system respectively according to the mapping relationship from the image coordinate systems of the left camera and the right camera to the world coordinate system for image stitching to obtain a stitched image.

Images