Concentricity determination method, apparatus, device, and storage medium

Abstract

The application relates to the technical field of battery cells and discloses a concentricity determination method, device, equipment and storage medium, which are applied to a post-welding detection process of a cell module. The method comprises the following steps: obtaining a post-welding module image of the cell module at a post-welding detection station; wherein the post-welding module image is in a post-welding detection coordinate system; the post-welding module image comprises the distribution state of a welding track formed on the cell module after a welding operation; determining the position data of a pole center point and the position data of a welding track center point on the cell module based on the post-welding module image; and performing concentricity calculation based on the position data of the pole center point and the position data of the welding track center point to obtain a concentricity result, so as to reflect the offset degree between the pole center point and the welding track center point. The method has the beneficial effects that the full automation of the concentricity detection process is realized, the accuracy and consistency of the detection result are significantly improved, and an efficient and reliable quantitative basis is provided for the quality evaluation and optimization of the welding process.

Description

Technical Field

[0001] This application relates to the field of battery cell technology, and in particular to a method, apparatus, device and storage medium for determining concentricity. Background Technology

[0002] In battery manufacturing, after stacking multiple cells to form a module, laser welding is used to firmly weld the Cell Contact System (CCS) to the cell terminals. The welding quality directly determines the conductivity and long-term reliability of the battery module. Concentricity is a key parameter for measuring welding quality; it specifically refers to the degree of misalignment between the center point of the weld seam formed by laser welding and the theoretical center point of the cell terminal. A smaller concentricity value indicates more precise alignment and higher welding quality.

[0003] In related technologies, the detection of concentricity in welding operations mostly relies on manual visual inspection and manual measurement. There is a need for a more accurate and efficient method for determining concentricity. Summary of the Invention

[0004] This application aims to at least partially solve one of the technical problems in related technologies. To this end, this application proposes a method, apparatus, device, and storage medium for determining concentricity. The main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a concentricity determination method applied to the post-weld inspection process of a battery cell module. The method includes: acquiring a post-weld image of the battery cell module at the post-weld inspection station; wherein the post-weld image is in a post-weld inspection coordinate system; the post-weld image includes the distribution of welding trajectories formed on the battery cell module after the welding operation; determining the position data of the electrode center point and the position data of the welding trajectory center point on the battery cell module based on the post-weld image; performing concentricity calculation based on the electrode center point position data and the welding trajectory center point position data to obtain a concentricity result; wherein the concentricity result reflects the degree of offset between the electrode center point and the welding trajectory center point.

[0005] Optionally, the method further includes: acquiring an addressing module image of the battery cell module at the addressing station; wherein the addressing module image is in an addressing coordinate system; the addressing module image is acquired using a two-dimensional acquisition device at the addressing station; determining a preset module distribution of the battery cell module based on the addressing module image; wherein the preset module distribution includes preset position data of the pole center point and first positioning data of the positioning point.

[0006] Optionally, the pole center point location data can be determined by the following methods: determining the pole center point location data based on a preset module distribution and a post-weld module image.

[0007] Optionally, determining the pole center point location data based on the preset module distribution and the post-weld module image includes: determining the second positioning data of the positioning point in the post-weld detection coordinate system in the post-weld module image; and determining the pole center point location data based on the preset module distribution and the second positioning data of the positioning point.

[0008] Optionally, determining the pole center point position data based on the preset module distribution and the second positioning data of the positioning points includes: determining the coordinate transformation relationship between the post-weld inspection coordinate system and the addressing coordinate system based on the first positioning data and the second positioning data of the positioning points; and determining the pole center point position data based on the coordinate transformation relationship and the preset position data of the pole center point.

[0009] Optionally, a welding trajectory is formed on the cell module by: acquiring an image of the cell module to be welded at the welding station; wherein the image of the cell module to be welded is in the welding coordinate system; the image of the cell module to be welded is acquired by a two-dimensional acquisition device at the welding station; determining the welding position data of the cell module in the welding coordinate system based on the preset module distribution; and performing welding operations within the preset range of the welding position data to form a welding trajectory on the cell module.

[0010] Optionally, the post-weld module images are acquired using two-dimensional and three-dimensional acquisition devices at the post-weld inspection station.

[0011] Secondly, embodiments of this application provide a concentricity determination device, applied in the post-welding inspection process of battery cell modules; the device includes: The post-welding image acquisition module is used to acquire post-welding module images of the battery cell module at the post-welding inspection station; wherein, the post-welding module image is in the post-welding inspection coordinate system; the post-welding module image includes the distribution state of the welding trajectory formed on the battery cell module after the welding operation; The actual position determination module is used to determine the position data of the electrode center point and the welding trajectory center point on the cell module based on the post-welding module image. The concentricity calculation module is used to calculate the concentricity based on the pole center point position data and the welding trajectory center point position data, and obtain the concentricity result; the concentricity result is used to reflect the degree of offset between the pole center point and the welding trajectory center point.

[0012] Thirdly, this application also provides a computer device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of any of the above methods.

[0013] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the methods described above.

[0014] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the above methods.

[0015] In the above embodiments, by acquiring post-weld module images and based on a unified post-weld inspection coordinate system, the positional data of the pole center point and the welding trajectory center point are quickly and conveniently determined, and then the degree of offset is calculated as the concentricity result. This effectively avoids the subjective errors and efficiency bottlenecks of manual visual inspection, realizes the full automation of the concentricity inspection process, significantly improves the accuracy and consistency of the inspection results, and ensures inspection efficiency, providing an efficient and reliable quantitative basis for the quality assessment and optimization of welding processes. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1a This is a flowchart of a concentricity determination method according to an embodiment of this application; Figure 1b This is a schematic diagram of a battery cell module provided according to an embodiment of this application; Figure 1c This is a schematic diagram of the structure of a battery cell according to an embodiment of this application; Figure 1d This is a schematic diagram illustrating the calculation of determining the welding trajectory according to an embodiment of this application; Figure 2a This is a flowchart of forming a welding trajectory according to yet another embodiment of this application; Figure 2b This is a schematic diagram of a pre-welding cell module according to yet another embodiment of this application; Figure 3 This is a structural block diagram of a concentricity determination device according to an embodiment of this application; Figure 4 This is an internal structural diagram of a computer device according to an embodiment of the present application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In battery manufacturing, after stacking multiple cells to form a module, laser welding is used to firmly weld the Cell Contact System (CCS) to the cell terminals. The welding quality directly determines the conductivity and long-term reliability of the battery module. Concentricity is a key parameter for measuring welding quality; it specifically refers to the degree of misalignment between the center point of the weld seam formed by laser welding and the theoretical center point of the cell terminal. A smaller concentricity value indicates more precise alignment and higher welding quality.

[0020] To achieve high-quality welding, it is essential to ensure that the welding equipment is precisely aligned with the center of the electrode post. However, in actual production, due to factors such as thickness variations among individual battery cells, tooling deviations in module positioning on the tray, and fluctuations in the positioning accuracy of the vision system across different workstations, there is often a difficult-to-detect offset between the actual laser welding trajectory and the center of the electrode post. In related technologies, compensating for this offset and accurately positioning the welding trajectory heavily relies on manual adjustments based on the operator's experience. This method is not only time-consuming and inefficient, but also struggles to guarantee consistency between different batches and modules.

[0021] Furthermore, after welding is completed, the assessment of weld quality (i.e., concentricity testing) in related technologies typically relies on manual visual inspection and offline sampling. This approach suffers from problems such as unstable measurement accuracy and the inability to systematically store and trace data, making it difficult to achieve full inspection and continuous optimization of process capabilities.

[0022] Therefore, from precise control of the welding process to quantitative evaluation of post-weld quality, the relevant technologies lack a complete, automated, efficient, and closed-loop feedback solution. This leads to difficulties in adjusting welding quality during production, as well as insufficient stability and traceability.

[0023] Based on this, according to the embodiments of this application, a method embodiment for determining concentricity is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0024] This embodiment provides a method for determining concentricity, such as Figure 1a As shown, this method is applied to the post-soldering inspection process of battery cell modules; the method includes the following steps: S110. Obtain the post-weld module image at the post-weld inspection station.

[0025] Among them, the post-weld module image refers to image data that can clearly show key features such as the position of the upper electrode post and the shape of the welding trajectory of the post-weld cell module. Specifically, the post-weld module image is in the post-weld inspection coordinate system, which is established based on the actual distribution characteristics of each component in the cell module at the post-weld inspection station.

[0026] It should be noted that, under normal process flow, before reaching the post-weld inspection station, the battery cell module needs to pass through the addressing station (for electrode position calibration and acquisition) and the welding station (for CCS installation and laser welding). Although the relative positions between the components of the battery cell module remain unchanged, in order to clearly distinguish the positioning references of different stations, it is necessary to establish a coordinate system corresponding to each station. Coordinate system A can be established at the addressing station, coordinate system B at the welding station, and coordinate system C at the post-weld inspection station. The reason for the differences in coordinate systems A, B, and C is that there are mechanical deviations when the battery cell module is transferred and positioned between different stations, as well as differences in the viewing angle when the vision system acquires images at different positions. This results in differences in the origin and coordinate axis directions of coordinate systems A, B, and C. However, since the relative positions between the electrodes of the battery cell module are fixed, the position data between different stations can be correlated through subsequent coordinate transformation.

[0027] Optionally, the post-weld module images are acquired using two-dimensional and three-dimensional acquisition devices at the post-weld inspection station.

[0028] Two-dimensional acquisition equipment can refer to high-resolution CCD industrial cameras, which can be used to quickly identify the planar positions of module marker points and poles. Three-dimensional acquisition equipment can refer to 3D cameras with laser scanning or structured light imaging capabilities, which can be used to acquire three-dimensional contour information of the weld surface.

[0029] Specifically, since a battery cell module typically integrates multiple cells, corresponding to multiple terminals and welds, the field of view of the acquisition device usually cannot cover the entire target at once to ensure image resolution and detection accuracy. Therefore, during the inspection process, the battery cell module can be fixed on a tray, and the vision acquisition system in the servo-driven motion module integrated in the post-weld inspection station can be used to position and photograph each terminal area on the battery cell module in sequence according to a preset path, such as from top to bottom or from left to right. Finally, the data is stitched together to obtain the complete position data of all terminals and welds in the entire module.

[0030] It's important to note that the reason for using 2D and 3D equipment in tandem is their complementary functionality. Specifically, 2D cameras are suitable for quickly and accurately extracting planar features, effectively extracting positioning points on the battery cell module used to establish a coordinate system, or identifying the distribution characteristics of the center points of concentric poles. Welds, formed by welding, exhibit significant height variations and three-dimensional morphological features, thus allowing for accurate fitting of their trajectory contours using a 3D camera. Optionally, in practical systems, 2D and 3D cameras are typically integrated into a vision acquisition system on the same servo system. Therefore, the 2D acquisition device can be controlled to first focus and capture images of the positioning points to establish a coordinate system. Then, the integrated 2D and 3D acquisition components can be controlled to move along a preset path, achieving continuous scanning and capturing of each welding area of ​​the module—essentially, rapid image capture. Thus, controlling their synchronous movement during data acquisition completes the acquisition of both the planar information of the poles and the three-dimensional information of the welds, avoiding the time wasted on separate acquisitions and ensuring the integrity and accuracy of the acquired data through functional complementarity.

[0031] It should be noted that the post-weld module image includes the distribution of the welding traces formed on the cell module after the welding operation.

[0032] Specifically, the welding operation refers to the process of laser welding the aluminum bar on the CCS onto the surface of the battery cell terminal. Understandably, to ensure the current-carrying area and connection reliability, welding is typically performed with the terminal center as a reference. A specific area is demarcated within the contact zone between the terminal and the aluminum bar, and the laser welds along this area, forming a ring-shaped or specific-shaped weld. The distribution of the welding trajectory refers to the actual shape of the laser beam trajectory on the module surface. Post-weld module images must clearly show the edges and contours of this trajectory to allow for subsequent image analysis to determine the center point of the welding trajectory.

[0033] S120. Determine the position data of the electrode center point and the welding trajectory center point based on the post-weld module image.

[0034] It should be noted that, please refer to Figure 1b A battery cell module refers to a core functional unit of a battery, which is assembled from multiple battery cells in a predetermined arrangement. Specifically, a schematic diagram of one such battery cell module can be found in [reference needed]. Figure 1c As shown, the surface of the battery cell is provided with metal protrusions for electrical energy conduction, namely the terminals; a plastic ring surrounding the terminals for insulation and protection; an injection port for injecting electrolyte during battery cell production; a QR code containing the battery cell module ID information; and an explosion-proof valve to ensure battery cell safety. Multiple such battery cells are neatly arranged horizontally and integrated into a single unit through structural components and electrical connection parts, thus forming a battery cell module.

[0035] Specifically, the center point of the electrode in the battery cell module refers to the geometric center position of each cell electrode on the upper surface of the module. These center points serve as the theoretical reference points for welding alignment. The center point position data can refer to the set of two-dimensional coordinates of each electrode center point in the post-weld inspection coordinate system. This data is not obtained by directly re-identifying the electrode at the post-weld inspection station, but rather by reading pre-stored calibration coordinates and transforming them to the current coordinate system.

[0036] The center point location data of the welding trajectory can refer to the coordinate data of the center line of the weld trajectory calculated by the three-dimensional distribution information of the weld in the post-weld module image, which can reflect the distribution of the actual action of the welding laser in the post-weld detection coordinate system.

[0037] Specifically, due to factors such as laser energy distribution and material melting and flow during welding, the actual weld is not a perfect circle, but rather an annular band of a certain width. Therefore, the process of determining the center point of the welding trajectory includes: First, using the 3D point cloud data of the weld acquired by a 3D acquisition device, the inner ring contour (diameter of the inner edge contour of the weld) and the outer ring contour (diameter of the outer edge contour of the weld) of the weld trajectory are fitted. Then, by calculating the maximum and minimum values ​​of the weld surface width, the average value is taken to obtain the centerline trajectory of the weld, and this trajectory is used as the actual laser beam trajectory. Finally, the position coordinates of its geometric center point are further calculated, thus obtaining the position data of the center point of the welding trajectory.

[0038] For example, please refer to Figure 1d This demonstrates the calculation principle of weld cross-section and centerline. The preset diameter of the welding reference circle (i.e., the diameter of the weld circle in the figure) is 10.6 mm. The inner diameter of the weld circle is 10.6 mm - 0.75 mm = 9.85 mm, and the outer diameter is 10.6 mm + 0.75 mm = 11.35 mm. By taking the average of the inner and outer ring dimensions of the weld trajectory, a beam trajectory that more closely matches the actual laser beam emission effect can be obtained. Based on this trajectory, the weld center point can be determined, effectively avoiding deviations caused by spatter, oxidation, and other interference at the weld edge, thus more accurately restoring the center position of the actual welding trajectory. Compared to related technologies that may only estimate based on a single contour, this method can more accurately eliminate the influence of weld morphology asymmetry caused by welding process fluctuations, thus more realistically reflecting the actual center of action of the laser beam and improving the accuracy and reliability of concentricity evaluation.

[0039] S130. Concentricity calculation is performed based on the pole center point position data and the welding trajectory center point position data to obtain the concentricity result.

[0040] The concentricity result is used to reflect the degree of offset between the center point of the pole post and the center point of the welding trajectory.

[0041] It should be noted that, theoretically, welding operations should be performed with the center point of the electrode post as the reference, and the center point of the electrode post and the center point of the welding trajectory should completely coincide. However, in actual production, due to factors such as differences in cell thickness, fluctuations in the shaping accuracy of positioning fixtures, accuracy deviations of the acquisition system, and drift of laser welding equipment parameters, the two will be offset. The quantitative result of this offset is the concentricity, and its value directly reflects whether the welding accuracy meets the standard.

[0042] Specifically, when calculating concentricity, all data can first be transformed into the same coordinate system, such as the post-weld inspection coordinate system. During the calculation, the coordinates of the pole center point (theoretical reference point) transformed into the post-weld inspection coordinate system (coordinate system C) can be compared with the coordinates of the welding trajectory center point (actual welding point) directly measured in coordinate system C.

[0043] Furthermore, the concentricity value can be obtained by calculating the Euclidean distance between two points, and the formula can be expressed as: Concentricity = |Coordinates of the pole center point in the post-weld inspection coordinate system - Coordinates of the weld trajectory center point in the post-weld inspection coordinate system|. This calculation directly reflects the straight-line distance deviation between the theoretical target and the actual result under the same spatial reference system, thus ensuring the accuracy and comparability of the evaluation results. Through this calculation, the offset distance between the two center points in the plane can be accurately quantified, providing data basis for judging whether the welding quality is qualified.

[0044] In the above implementation, by acquiring post-weld module images and using a unified post-weld inspection coordinate system, the positional data of the pole center point and the welding trajectory center point are quickly and conveniently determined, and then the degree of offset is calculated as the concentricity result. This effectively avoids the subjective errors and efficiency bottlenecks of manual visual inspection, realizes the full automation of the concentricity inspection process, significantly improves the accuracy and consistency of the inspection results, and ensures inspection efficiency, providing an efficient and reliable quantitative basis for the quality assessment and optimization of the welding process.

[0045] In some implementations, the pole center point location data is determined by the following methods: determining the pole center point location data based on a preset module distribution and a post-soldering module image.

[0046] The preset module distribution refers to a set of data acquired in the early stages of the module production process, reflecting the relative positional relationships between the components of the battery cell module. This data set is generated at the beginning of the process flow, stored in a control system such as a PLC, and serves as a positional reference for subsequent welding control and post-weld inspection. The preset module distribution includes, but is not limited to: the arrangement order and relative spacing of each battery cell in the entire module, the positional information of the positioning points (marking points) used for positioning on the module tray or end plate, the relative coordinates of each terminal post within the module, and the unique barcode information used to identify the module.

[0047] Optionally, the preset module distribution can be determined by the following method: First, acquire the addressing module image of the cell module at the addressing station. Then, determine the preset module distribution of the cell module based on the addressing module image.

[0048] The addressing module image refers to image data acquired by a vision system at the addressing station, reflecting the positioning points and pole positions of the module. Specifically, the addressing module image is in an addressing coordinate system, which can be established based on the image features of the positioning points in the addressing module image. It should be noted that since the main purpose of the addressing station is to accurately obtain the planar position of the poles, the requirement for three-dimensional shape information is not high. Therefore, the addressing module image can be acquired using a two-dimensional acquisition device at the addressing station. For example, the addressing station can also be configured with a vision acquisition system mounted on a servo drive system. During acquisition, the two-dimensional acquisition device moves sequentially along the module layout path according to a preset path, capturing images of each pole area to obtain a complete addressing module image.

[0049] Furthermore, the preset module distribution includes preset position data for the electrode center point and first positioning data for the positioning point. The preset position data for the electrode center point can refer to the coordinate values ​​of the geometric center of each cell electrode calculated through image analysis in the addressing coordinate system. This data is stored in the PLC and serves as the preset position reference for subsequent welding and inspection.

[0050] The first positioning data for the positioning point can refer to the coordinate values ​​of the positioning point on the module tray or end plate in the addressing coordinate system. It should be noted that the positioning point can refer to a physical marker point (Marking Point) with a specific shape (such as a round hole or a waist-shaped hole) set on the module tray or end plate. For example, a cell module with epoxy board structures on both sides can use the round hole or waist-shaped hole on the tray as the Marking Point; while a cell module with die-cast end plates on both sides can define the round hole or waist-shaped hole on the die-cast end plate as the Marking Point. Specifically, when determining the preset module distribution, by analyzing the addressing module image, the coordinates of the positioning points (i.e., the first positioning data for the positioning point) and the coordinates of the center point of each pole (i.e., the preset position data of the pole center point) can be identified simultaneously.

[0051] Further, the process of obtaining the preset module distribution can be as follows: First, the stacked battery cell modules are placed on a tray and fixed, and then moved to the addressing station (addressing room). Then, a two-dimensional acquisition device is used to acquire and analyze the addressing module image at the addressing station to determine at least two positioning points on the battery cell module as a fixed set of marking points. The coordinate data of this set of positioning points at the addressing station is recorded as the first positioning data of the positioning points. Subsequently, an addressing coordinate system is established based on this set of positioning points. For example, one of the positioning points can be selected as the origin of the coordinate system, and the remaining points can be used as reference points to determine the direction of the coordinate axes, thereby establishing the addressing coordinate system. Next, the acquisition device is controlled to move along a preset path to determine the coordinates of the center point of each battery cell terminal in the addressing coordinate system, obtaining the preset position data of the terminal center point, such as J1(x1,y1), J2(x2,y2), etc. At the same time, the unique identification information of the battery cell module obtained through RFID and other means can be associated with the selected positioning point coordinates and the calculated pole coordinates and stored in the control system (such as PLC) to form the preset module distribution of the module.

[0052] This method allows for the pre-establishment of a precise internal position reference database for the module before it enters subsequent workstations, providing a data foundation for subsequent coordinate transformation and accurate positioning.

[0053] Furthermore, if the position data of the pole center point is to be determined based on the preset module distribution and the post-weld module image, the second positioning data of the positioning point in the post-weld inspection coordinate system can first be determined in the post-weld module image. Then, the position data of the pole center point can be determined based on the preset module distribution and the second positioning data of the positioning point.

[0054] The second positioning data of the positioning point can refer to the coordinate values ​​of the selected positioning points of the same group of the battery cell module, which are re-identified from the post-weld module image under the post-weld inspection coordinate system.

[0055] It should be noted that the second positioning data and the first positioning data are essentially the same set of positioning points expressed in different coordinate systems (addressing coordinate system and post-weld inspection coordinate system, respectively).

[0056] Similarly, the method for determining the second positioning data of the positioning point is similar to that of the first positioning data of the positioning point. It involves analyzing the post-weld module image, identifying the pixel position of the positioning point, and then converting it to the physical coordinates in the post-weld detection coordinate system.

[0057] Furthermore, based on the preset module distribution and the second positioning data of the positioning points, the position data of the pole center points can be determined. First, the coordinate transformation relationship between the post-weld inspection coordinate system and the addressing coordinate system can be determined based on the first and second positioning data of the positioning points. Then, based on this coordinate transformation relationship, the preset position data of the pole center points stored in the PLC can be substituted into this transformation relationship for conversion mapping to obtain the corresponding coordinates of these pole center points in the post-weld inspection coordinate system, thus obtaining the pole center point position data.

[0058] For example, in the actual testing process, after a battery cell module arrives at the post-weld inspection station, the module barcode information on the current module tray is first obtained through an RFID reader to determine the ID information of the battery cell module. Then, based on this, the preset module distribution recorded during the addressing phase and stored in the PLC is retrieved. Simultaneously, the testing equipment captures an image of the post-weld module in the post-weld inspection coordinate system. Image processing is used to identify and calculate the coordinates of selected positioning points in the same group within the post-weld inspection coordinate system, obtaining the second positioning data for the positioning points. Subsequently, based on the first and second positioning data of the positioning points in the same group, a coordinate transformation relationship between the addressing coordinate system (coordinate system A) and the post-weld inspection coordinate system (coordinate system C) is calculated using a coordinate mapping algorithm (such as the least squares method). Finally, this coordinate transformation relationship is used to transform the preset position data of all electrode center points on the battery cell module from coordinate system A to coordinate system C, obtaining the electrode center point position data in the post-weld inspection coordinate system. By using coordinate transformation based on the preset module distribution to determine the center point location data of the pole, the re-identification of poles that may be partially obscured at the post-weld inspection station is avoided, ensuring the accuracy and reliability of the reference data, and is also more efficient.

[0059] Optionally, when acquiring image data of the current workstation using 2D and 3D acquisition devices, a grating ruler can be added for hard-triggered acquisition. Specifically, as the servo system moves the vision acquisition component, the grating ruler detects its precise position in real time. When the system moves to a preset acquisition point, the position feedback signal generated by the grating ruler will directly trigger the camera to take a picture, thereby realizing hard-triggered acquisition based on physical position.

[0060] In the above implementation, by combining the preset module distribution with the current workstation image data, the theoretical position of the pole column is accurately transferred from the preset calibration coordinate system to the actual coordinate system of the final detection, providing a reliable theoretical reference point for the accurate calculation of concentricity.

[0061] In some implementation methods, please refer to the appendix. Figure 2a Welding tracks are formed on the battery cell module in the following manner: S210. Obtain the image of the battery cell module to be welded at the welding station.

[0062] The image of the module to be welded refers to image data acquired at the welding station through a vision acquisition system, which clearly shows the various components of the battery cell module. Specifically, the image of the module to be welded is in a welding coordinate system, which can be established based on the image features of the positioning points contained in the image of the module to be welded. Furthermore, the image of the module to be welded can also be acquired at the welding station using a two-dimensional acquisition device.

[0063] Specifically, since the battery cell module being tested has already completed the collection and storage of the preset module distribution at the addressing station, when the battery cell module is transported to the welding area of ​​the welding station by the double-speed chain, the two-dimensional acquisition device can also be controlled to take pictures of the battery cell module, and then a welding coordinate system (which can be denoted as coordinate system B) can be established based on the position data of the identified positioning points.

[0064] S220. Determine the welding position data of the cell module in the welding coordinate system based on the preset module distribution.

[0065] Among them, the welding position data can refer to the coordinate information of the center point of each electrode post in the welding coordinate system (coordinate system B) when the battery cell module is located at the welding station, which is used to guide the positioning of the laser welding equipment's output trajectory.

[0066] Specifically, the process of determining the welding position data is similar to the transformation from the addressing coordinate system to the post-weld inspection coordinate system. First, after a battery cell module arrives at the welding station, confirming that it has completed electrode cleaning and CCS installation and is ready for laser welding, and then fixing it in place, the module barcode information on the current module tray is obtained via an RFID reader to determine the ID information of the battery cell module. Simultaneously, the coordinates of selected positioning points in the same group under the welding coordinate system are identified and determined from the acquired image of the module to be welded (this can be called the third positioning data of the positioning points). Then, the first positioning data of the positioning points is obtained by calling the preset module distribution stored in the PLC. Next, based on these two sets of positioning point coordinate data, the coordinate transformation relationship from the addressing coordinate system (coordinate system A) to the welding coordinate system (coordinate system B) is calculated. Finally, this transformation relationship is used to transform the preset position data of the electrode center point to the welding coordinate system, thereby obtaining the welding position data.

[0067] S230. Perform welding operations within the preset range of the data of the position to be welded, so as to form a welding trajectory on the cell module.

[0068] Understandably, before performing the welding operation, the CCS must first be installed above the module pole, as can be seen in the following reference. Figure 2bAs shown, the observation hole on the CCS aluminum bar should be roughly aligned with the center of the electrode post. Since the welding operation itself aims to achieve a reliable electrical connection between the CCS aluminum bar and the battery cell electrode post, ensuring sufficient current-carrying area and mechanical strength, a pre-defined welding area can be set as the welding preset range for production needs. This preset range is defined with the welding position data (i.e., the coordinates of the electrode post center point in coordinate system B) as the center. Furthermore, this range needs to cover the effective contact area between the electrode post and the aluminum bar while matching the laser welding process parameters, thereby ensuring alignment accuracy while accommodating minor process fluctuations.

[0069] It is important to reiterate that the placement and positioning references of the module change when it is transferred from the addressing station to the welding station. If the welding equipment is controlled directly according to the coordinate data in the addressing coordinate system recorded in the PLC, welding misalignment is likely to occur due to station differences. Therefore, a welding coordinate system must first be established at the welding station. The precise position of the pole at that station (the position data to be welded) is obtained through coordinate transformation. Then, the welding equipment is controlled to weld within the preset range of the welding coordinate system. This significantly improves welding accuracy and reduces the error and frequency of manual machine adjustments.

[0070] Specifically, before and after actual welding, the addressing accuracy can be further calculated to precisely control the welding operation. The formula for calculating this addressing accuracy is the absolute value of the sum of the distance between two marker points in the addressing coordinate system and the distance between corresponding marker points in the welding coordinate system, divided by the total distance between the two marker points in the welding coordinate system. Furthermore, if the addressing accuracy is greater than a preset threshold (e.g., 0.5%), the system can be set to automatically trigger an alarm and prompt for calibration. If the addressing accuracy is less than or equal to the threshold, it proves that the coordinate transformation is correct and reliable. The laser welding equipment can then plan a light trajectory within a preset range, using the center point of the electrode in the welding position data as the center. Laser welding is then initiated, causing the laser to act along the planned trajectory on the contact area between the electrode and the CCS aluminum bar, forming a continuous welding mark (i.e., the welding trajectory).

[0071] Optionally, before officially starting the overall process flow, calibration blocks can be set at each station to minimize errors in the acquisition equipment. The calibration block can be a reference device (Master unit) with known precise dimensions (e.g., including specific length, width, and step height). By controlling the vision acquisition system at each station to measure the same calibration block, and comparing the measured image data with the known physical dimensions of the calibration block, the inherent mapping errors of the vision system (such as lens distortion, installation position deviation, etc.) can be calculated and compensated.

[0072] In the above implementation, a current coordinate system is established by acquiring an image of the welding station, and precise welding position data is obtained by coordinate transformation based on a preset module distribution. Finally, welding is completed within a controlled preset range, forming a welding trajectory. This method effectively overcomes the problem of inaccurate welding alignment caused by module positioning deviation, realizes automation and precision in the welding process, lays a solid foundation for obtaining good concentricity results, and improves production efficiency and process consistency.

[0073] It should be understood that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart above may include multiple steps or stages, which are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps.

[0074] This specification also provides a concentricity determination device 300, applied to the post-welding inspection process of battery cell modules. For example... Figure 3 As shown, the concentricity determination device 300 includes: a post-weld image acquisition module 310, an actual position determination module 320, and a concentricity calculation module 330, wherein: The post-weld image acquisition module 310 is used to acquire the post-weld module image of the battery cell module at the post-weld inspection station; wherein, the post-weld module image is in the post-weld inspection coordinate system; the post-weld module image includes the distribution state of the welding trajectory formed on the battery cell module after the welding operation.

[0075] The actual position determination module 320 is used to determine the position data of the pole center point and the welding trajectory center point on the cell module based on the post-weld module image.

[0076] The concentricity calculation module 330 is used to calculate the concentricity based on the pole center point position data and the welding trajectory center point position data to obtain the concentricity result; wherein, the concentricity result is used to reflect the degree of offset between the pole center point and the welding trajectory center point.

[0077] In some embodiments, a concentricity determination device 300 further includes a preset module distribution determination module, used to acquire an addressing module image of the battery cell module at the addressing station; wherein, the addressing module image is in an addressing coordinate system; the addressing module image is acquired using a two-dimensional acquisition device at the addressing station; the preset module distribution of the battery cell module is determined based on the addressing module image; wherein, the preset module distribution includes preset position data of the pole center point and first positioning data of the positioning point.

[0078] In some implementations, the actual position determination module 320 is also used to determine the position data of the pole center point based on the preset module distribution and the post-weld module image.

[0079] In some implementations, the actual position determination module 320 is also used to determine the second positioning data of the positioning point in the post-weld detection coordinate system in the post-weld module image; and to determine the position data of the pole center point based on the preset module distribution and the second positioning data of the positioning point.

[0080] In some implementations, the actual position determination module 320 is also used to determine the coordinate transformation relationship between the post-weld inspection coordinate system and the addressing coordinate system based on the first positioning data and the second positioning data of the positioning point; and to determine the position data of the pole center point based on the coordinate transformation relationship and the preset position data of the pole center point.

[0081] In some embodiments, a concentricity determination device 300 further includes a welding module for acquiring an image of the battery cell module to be welded at a welding station; wherein the image of the module to be welded is in a welding coordinate system; the image of the module to be welded is acquired using a two-dimensional acquisition device at the welding station; the welding position data of the battery cell module in the welding coordinate system is determined based on a preset module distribution; welding operations are performed within a preset range of the welding position data to form a welding trajectory on the battery cell module.

[0082] In some embodiments, the post-weld image acquisition module 310 is also used to acquire post-weld module images at the post-weld inspection station using two-dimensional and three-dimensional acquisition devices.

[0083] For specific limitations regarding the concentricity determination device, please refer to the limitations of the concentricity determination method described above, which will not be repeated here. Each module in the aforementioned concentricity determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. In this embodiment, the concentricity determination device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the aforementioned functions.

[0084] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a computer device provided in an embodiment of this application, such as... Figure 4 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 4 Take a processor 10 as an example.

[0085] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0086] The memory 20 stores instructions executable by at least one processor 10 to cause the processor 10 to perform the methods shown in the above embodiments. The memory 20 may include a stored program area and a stored data area. The stored program area may store the operating system and applications required for at least one function; the stored data area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some optional embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0087] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0088] The computer device also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 4 Taking the example of a connection between China and Israel via a bus.

[0089] Input device 30 can receive input numerical or character information, and generate key signal inputs related to user settings and function control of the computer device, such as a touchscreen, keypad, mouse, trackpad, touchpad, joystick, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touchscreen.

[0090] This application also provides a computer-readable storage medium. The methods described in this application can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code downloaded over a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods shown in the above embodiments are implemented.

[0091] This application provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method of any embodiment of this application.

[0092] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

[0093] The systems, apparatuses, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices. For ease of description, the above apparatuses are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware. Those skilled in the art should understand that the embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart and / or block diagram, and combinations of blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart and / or one or more blocks of the block diagram. These computer program instructions may also be stored in a computer-readable storage medium capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more blocks of the flowchart and / or one or more blocks of the block diagram. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more blocks of the flowchart and / or one or more blocks of the block diagram.

[0094] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover 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 limitation, 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 said element.

[0095] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0096] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application. Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for determining concentricity, characterized in that, The method is applied to the post-welding inspection process of battery cell modules; the method includes: Acquire an addressing module image of the battery cell module at the addressing station; wherein, the addressing module image is in the addressing coordinate system; the addressing module image is acquired using a two-dimensional acquisition device at the addressing station; The preset module distribution of the battery cell module is determined based on the addressing module image; wherein, the preset module distribution includes preset position data of the pole center point and first positioning data of the positioning point; A post-weld image of the battery cell module is acquired at the post-weld inspection station; wherein the post-weld image is in the post-weld inspection coordinate system; the post-weld image includes the distribution of the welding trajectory formed on the battery cell module after the welding operation; the welding trajectory is formed by the following method: obtaining welding position data based on the image of the module to be welded and the preset module distribution; performing a welding operation within a preset range of the welding position data to form the welding trajectory on the battery cell module; wherein the image of the module to be welded is in the welding coordinate system; Determining the center point position data of the electrode post on the battery cell module and the center point position data of the welding trajectory based on the post-weld module image includes: determining the center point position data of the electrode post based on the preset module distribution and the post-weld module image; fitting the inner ring contour and outer ring contour of the weld trajectory using the three-dimensional point cloud data of the weld obtained by the three-dimensional acquisition device; calculating the mean of the inner ring contour and the outer ring contour as the actual light emission trajectory; calculating the position coordinates of the geometric center point of the actual light emission trajectory, thereby obtaining the center point position data of the welding trajectory. Based on the position data of the pole center point and the position data of the welding trajectory center point, concentricity calculation is performed to obtain the concentricity result; wherein, the concentricity result is used to reflect the degree of offset between the pole center point and the welding trajectory center point.

2. The method according to claim 1, characterized in that, The step of determining the position data of the pole center point based on the preset module distribution and the post-weld module image includes: Determine the second positioning data of the positioning point in the post-weld detection coordinate system in the post-weld module image; The position data of the pole center point is determined based on the preset module distribution and the second positioning data of the positioning point.

3. The method according to claim 2, characterized in that, The step of determining the position data of the pole center point based on the preset module distribution and the second positioning data of the positioning point includes: Based on the first positioning data and the second positioning data of the positioning point, determine the coordinate transformation relationship between the post-weld inspection coordinate system and the addressing coordinate system; The position data of the polar center point is determined based on the coordinate transformation relationship and the preset position data of the polar center point.

4. The method according to claim 1, characterized in that, The welding traces are formed on the battery cell module in the following manner: The image of the battery cell module to be welded at the welding station is obtained; wherein the image of the module to be welded is obtained by acquiring it at the welding station using a two-dimensional acquisition device; Based on the preset module distribution, determine the welding position data of the cell module in the welding coordinate system; Welding operations are performed within a preset range of the data of the position to be welded, so as to form the welding trajectory on the cell module.

5. The method according to claim 1, characterized in that, The post-weld module image was obtained by using two-dimensional and three-dimensional acquisition devices at the post-weld inspection station.

6. A concentricity determining device, characterized in that, The device is used in the post-weld inspection process of battery cell modules; the device includes: The post-welding image acquisition module is used to acquire the addressing module image of the battery cell module at the addressing station; wherein, the addressing module image is in the addressing coordinate system; the addressing module image is acquired by a two-dimensional acquisition device at the addressing station; The preset module distribution of the battery cell module is determined based on the addressing module image; wherein, the preset module distribution includes preset position data of the pole center point and first positioning data of the positioning point; A post-weld image of the battery cell module is acquired at the post-weld inspection station; wherein the post-weld image is in the post-weld inspection coordinate system; the post-weld image includes the distribution of the welding trajectory formed on the battery cell module after the welding operation; the welding trajectory is formed by the following method: obtaining welding position data based on the image of the module to be welded and the preset module distribution; performing a welding operation within a preset range of the welding position data to form the welding trajectory on the battery cell module; wherein the image of the module to be welded is in the welding coordinate system; The actual position determination module is used to determine the position data of the electrode center point and the welding trajectory center point on the cell module based on the post-weld module image; including: determining the position data of the electrode center point based on the preset module distribution and the post-weld module image; fitting the inner ring contour and outer ring contour of the weld trajectory using the three-dimensional point cloud data of the weld obtained by the three-dimensional acquisition device; calculating the mean of the inner ring contour and the outer ring contour as the actual light emission trajectory; calculating the position coordinates of the geometric center point of the actual light emission trajectory, thereby obtaining the position data of the welding trajectory center point; The concentricity calculation module is used to calculate the concentricity based on the position data of the pole center point and the position data of the welding trajectory center point to obtain the concentricity result; wherein, the concentricity result is used to reflect the degree of offset between the pole center point and the welding trajectory center point.

7. A computer device, characterized in that, include: A memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, the processor executing the computer instructions to perform the method of any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the method of any one of claims 1 to 5.

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