Preparation method of photovoltaic module and photovoltaic module

Abstract

The invention relates to the field of photovoltaic technology, and discloses a preparation method of a photovoltaic module and the photovoltaic module, and the preparation method of the photovoltaic module comprises the steps: obtaining first compensation data of a first battery piece in a process that a manipulator grabs the first battery piece from a first transmission device and places the first battery piece on a second transmission device; the first compensation data represents the position deviation of the first battery piece on the first transmission device; acquiring second compensation data of the first battery piece; the second compensation data represents the position deviation between the first battery piece and the second transmission device under the condition that the first battery piece reaches the target range of the second transmission device and is not placed on the second transmission device; acquiring target compensation data according to the first compensation data and the second compensation data so as to control a manipulator to adjust the position of the first battery piece placed on a second transmission device based on the target compensation data; therefore, the deviation of the battery pieces in the negative spacing series welding process is reduced, and the yield of photovoltaic modules is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a method for preparing a photovoltaic module and a photovoltaic module. Background Art

[0002] During the production of photovoltaic modules, cell string welding plays a decisive role in improving the power and mechanical reliability of photovoltaic modules. To increase the power of photovoltaic modules, negative spacing string welding has become the main development trend of cell string welding. Negative spacing string welding is to physically overlap the front main grid area of ​​the subsequent cell on the back electrode area of ​​the previous cell, forming a negative cell pitch.

[0003] However, the current cell has large errors in the negative pitch string welding process, resulting in a low yield of photovoltaic modules and failing to meet the design requirements of photovoltaic modules. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a method for preparing a photovoltaic module and a photovoltaic module, thereby reducing the deviation of the battery cells during the negative pitch string welding process and improving the yield of the photovoltaic module.

[0005] To solve the above technical problems, an embodiment of the present application provides a method for preparing a photovoltaic module, including: obtaining first compensation data of the first cell from a first transmission device and placing it on a second transmission device in a process in which a robot grabs the first cell from a first transmission device and places it on a second transmission device; the first compensation data represents the position deviation of the first cell on the first transmission device; obtaining second compensation data of the first cell; the second compensation data represents the position deviation of the first cell between the second transmission device when the first cell reaches the target range of the second transmission device and is not placed on the second transmission device; obtaining target compensation data based on the first compensation data and the second compensation data to control the robot to adjust the position of the first cell placed on the second transmission device based on the target compensation data.

[0006] An embodiment of the present application further provides a photovoltaic module, which is prepared by the above-mentioned method for preparing a photovoltaic module.

[0007] In some embodiments, obtaining the first compensation data of the first battery cell includes: obtaining first image data of the first battery cell on the first transmission device; the first image data is obtained by a CCD camera using a circularly polarized light source; using a Canny edge detection algorithm to extract a first contour image of the first battery cell in the first image data; extracting a maximum connected domain in the first contour image, and determining the center position data of the first battery cell in the maximum connected domain; obtaining the first compensation data based on the deviation between the center position data and the target center position in the first transmission device; wherein the first compensation data includes a first compensation amount in a first direction, a second compensation amount in a second direction, and a compensation angle; the first direction is the moving direction of the first transmission device, and the second direction is perpendicular to the first direction and parallel to the surface of the first transmission device on which the first battery cell is placed.

[0008] In some embodiments, obtaining the second compensation data of the first battery cell includes: obtaining the first edge feature data of the first battery cell when the first battery cell reaches the target range of the second transmission device and is not placed on the second transmission device, and obtaining the second edge feature data of the second battery cell located on the second transmission device; when the first battery cell is placed on the second transmission device, the first battery cell is adjacent to the second battery cell; obtaining the optimal offset between the first battery cell and the second battery cell based on the first edge feature data and the second edge feature data; obtaining the second compensation data based on the first edge feature data, the target position on the second transmission device, and the optimal offset.

[0009] In some embodiments, obtaining the first edge feature data of the first battery cell includes: synchronously scanning the first battery cell through at least one laser sensor to obtain first point cloud data; the laser sensor is set on the second transmission device; and edge extraction is performed on the first point cloud data to obtain the first edge feature data; obtaining the second edge feature data of the second battery cell located on the second transmission device includes: synchronously scanning the second battery cell through at least one laser sensor to obtain second point cloud data; and edge extraction is performed on the second point cloud data to obtain the second edge feature data.

[0010] In some embodiments, obtaining the optimal offset between the first battery cell and the second battery cell based on the first edge feature data and the second edge feature data includes: obtaining the first edge curvature of the first battery cell based on the first edge feature data; obtaining the second edge curvature of the second battery cell based on the second edge feature data; and using a curvature matching algorithm to obtain the optimal offset between the first edge curvature and the second edge curvature.

[0011] In some embodiments, the second compensation data is obtained based on the first edge feature data, the target position on the second transmission device, and the optimal offset, including: extracting the first position information of any target edge point in the first edge feature data; extracting the second position information corresponding to the target edge point in the target position on the second transmission device; obtaining the second compensation data based on the first position information, the second position information, the optimal offset, and the compensation angle; wherein the second compensation data includes a third compensation amount in a third direction and a fourth compensation amount in a fourth direction; the third direction is the moving direction of the second transmission device, and the fourth direction is perpendicular to the third direction and parallel to the surface of the second transmission device on which the second battery cell is placed.

[0012] In some embodiments, obtaining target compensation data based on the first compensation data and the second compensation data includes: determining a first weight of the first compensation data and a second weight of the second compensation data according to an exponential decay weight; the first weight is directly proportional to the exponential decay weight, and the second weight is inversely proportional to the exponential decay weight; obtaining the target compensation data based on the first compensation data, the second compensation data, the first weight, and the second weight.

[0013] In some embodiments, the method further includes: obtaining third compensation data of the first battery cell; the third compensation data includes at least one of the following compensations: thermal expansion compensation, vibration compensation, and belt slip compensation; obtaining target compensation data based on the first compensation data and the second compensation data includes: obtaining target compensation data based on the first compensation data, the second compensation data, and the third compensation data.

[0014] In some embodiments, obtaining target compensation data based on the first compensation data, the second compensation data, and the third compensation data includes: obtaining fourth compensation data based on the second compensation data and the third compensation data; determining the third weight of the first compensation data and the fourth weight of the fourth compensation data according to the exponential decay weight; the third weight is proportional to the exponential decay weight, and the fourth weight is inversely proportional to the exponential decay weight; obtaining the target compensation data based on the first compensation data, the fourth compensation data, the third weight, and the fourth weight.

[0015] The technical solution provided by the embodiments of the present application has at least the following advantages: The present application obtains first compensation data of the first battery cell on the first transmission device and second compensation data of the first battery cell reaching the target range of the second transmission device but not being placed on the second transmission device, and obtains target compensation data based on the first compensation data and the second compensation data to control the manipulator to adjust the position of the first battery cell on the second transmission device based on the target compensation data. In the process of the manipulator grabbing the first battery cell from the first transmission device and placing it on the second transmission device, the placement position of the end of the manipulator is detected in real time and adjusted accordingly, thereby reducing the deviation of the battery cell during the negative spacing string welding process, getting rid of the deviation of the accuracy of the cell placement system of the string welding equipment and the influence of the cell tolerance on the string welding deviation, and improving the yield of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 1 is a schematic structural diagram of a laser dynamic deviation correction system according to an embodiment of the present application; Figure 2 is a schematic flow chart of a method for preparing a photovoltaic module according to an embodiment of the present application; Figure 3 is a flowchart of the sub-steps of step 101 according to an embodiment of the present application; Figure 4 is a flowchart of the sub-steps of step 102 according to an embodiment of the present application; Figure 5 is a flowchart of the sub-steps of step 1022 according to an embodiment of the present application; Figure 6 is a flowchart of the sub-steps of step 1023 according to an embodiment of the present application; Figure 7 is a flowchart of the sub-steps of step 103 according to an embodiment of the present application; Figure 8 1 is another schematic flow chart of a method for preparing a photovoltaic module according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] As can be seen from the background art, the current battery cells have large errors during the negative spacing string welding process and cannot meet the design requirements of photovoltaic modules.

[0019] Through analysis and research, it was found that the reason why the current battery cells have large errors in the negative spacing string welding process is that: the current photovoltaic module stacking process requires a negative spacing of approximately -0.4mm, with an allowable deviation of ±0.1mm, but the current string welding equipment's cell placement system has an accuracy deviation of ±0.3mm (regular CCD camera positioning ±0.15mm, handling robot ±0.05mm, belt transmission ±0.1mm), and the cell tolerance is ±0.2mm (including battery tolerance ±0.1mm, dicing accuracy ±0.1mm). After the two are superimposed in the same direction, the maximum deviation is ±0.5mm, far exceeding the product design requirement of -0.4mm±0.1mm. Monte Carlo simulation data was used to analyze the rejection rate and concluded that, given a maximum deviation of ±0.5mm, the probability that the final product's stacking pitch would exceed the designed stacking pitch of -0.4mm ±0.1mm exceeds 18%. This results in significant errors during the negative-pitch string soldering process, posing a risk of light leakage from the visible panels of the PV modules. This results in poor power and mechanical reliability, and fails to meet the design requirements. The table below shows the error sources and values ​​for each step in the existing negative-pitch string soldering process.

[0020]

[0021] Furthermore, existing soldering systems experience static compensation failure during the production of FP (Full Plate) shingled modules, meaning dynamic offset cannot be suppressed. The existing system relies on a regular CCD (Charge-Coupled Device) camera for position compensation before placing the cells, but this cannot address dynamic disturbances during placement. Belt vibration can cause cell slippage, and thermal elongation of the belt increases the belt's cumulative error. The robot has inertia, causing overshoot during emergency stops, which can easily lead to hidden cracks in thin cell scenarios. The soldering system currently only supports adjustment in the X direction and relies on initial CCD compensation in the Y direction, which can easily lead to accumulated misalignment, reducing the overlap area of ​​the stacked cells and causing light leakage. Furthermore, the handling arm is rigidly fixed in the Y direction and cannot respond to belt deviation (a typical deviation of 0.5° results in a 0.3mm end offset). However, current detection feedback is lacking. The current system does not perform real-time detection after the wafer is placed. Defects are usually discovered after the component is packaged. In addition, the EL (Electroluminescence) detection response delay is long, resulting in the batch production of defective products and a low yield rate of photovoltaic modules.

[0022] In order to solve the above technical problems, the present application provides a method for preparing a photovoltaic module, including: obtaining first compensation data of the first cell when a robot grabs the first cell from a first transmission device and places it on a second transmission device; the first compensation data represents the position deviation of the first cell on the first transmission device; obtaining second compensation data of the first cell; the second compensation data represents the position deviation of the first cell between the second transmission device when the first cell reaches the target range of the second transmission device and is not placed on the second transmission device; obtaining target compensation data based on the first compensation data and the second compensation data to control the robot to adjust the position of the first cell placed on the second transmission device based on the target compensation data.

[0023] The present application obtains first compensation data of the first battery cell on the first transmission device and second compensation data of the first battery cell reaching the target range of the second transmission device but not being placed on the second transmission device, and obtains target compensation data based on the first compensation data and the second compensation data to control the manipulator to adjust the position of the first battery cell on the second transmission device based on the target compensation data. In the process of the manipulator grabbing the first battery cell from the first transmission device and placing it on the second transmission device, the placement position of the end of the manipulator is detected in real time and adjusted accordingly, thereby reducing the deviation of the battery cell during the negative spacing string welding process, getting rid of the deviation of the accuracy of the cell placement system of the string welding equipment and the influence of the cell tolerance on the string welding deviation, and improving the yield of photovoltaic modules.

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below with reference to the accompanying drawings. However, it will be understood by those skilled in the art that in each embodiment of the present application, many technical details are proposed to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present application can be implemented. The division of the following embodiments is for convenience of description and should not constitute any limitation on the specific implementation of the present application. The various embodiments can be combined and referenced with each other under the premise of no contradiction.

[0025] An embodiment of the present application relates to a method for preparing a photovoltaic module. The method for preparing a photovoltaic module of this embodiment is based on a laser dynamic deviation correction system. Figure 1 As shown, it is a structural schematic diagram of the laser dynamic correction system of this embodiment, including a first transmission device, a second transmission device, and a manipulator. The first transmission device is a feeding belt, and the first transmission device is provided with a CCD camera. The second transmission device is a welding belt, and the second transmission device is provided with a laser sensor. The number of laser sensors can be 3, 1 laser sensor is set in the belt transmission direction, and 2 laser sensors are respectively set on the upper and lower sides of the belt; the manipulator is provided with a welding press and a feeding suction cup, and the manipulator is used to grab the first battery cell from the first transmission device through the feeding suction cup and place it on the second transmission device. After that, the second transmission device, i.e., the welding belt, fixes multiple battery cells through vacuum adsorption or mechanical clamps to prevent them from moving during the welding process, ensuring that welding presses such as laser welding heads and arc welding guns can be welded in precise positions to form battery strings.

[0026] The manipulator of this embodiment is controlled by a piezoelectric controller in a piezoelectric micro-motion platform. The piezoelectric controller controls the manipulator to grab the first battery cell from the first transmission device and place it on the second transmission device. The first compensation data of the first battery cell on the first transmission device is obtained by a CCD camera. The second compensation data of the first battery cell and the second transmission device are obtained by a laser sensor when the first battery cell reaches the target range of the second transmission device and is not placed on the second transmission device. The target compensation data is obtained based on the first compensation data and the second compensation data to control the manipulator to adjust the position of the first battery cell on the second transmission device based on the target compensation data. Therefore, when the manipulator grabs the first battery cell from the first transmission device and places it on the second transmission device, the placement position of the end of the manipulator is detected in real time and adjusted accordingly, thereby reducing the deviation of the battery cell during the negative pitch string welding process and improving the yield of the photovoltaic module.

[0027] like Figure 2FIG. 1 is a flow chart of a method for preparing a photovoltaic module according to an embodiment of the present invention. The method for preparing a photovoltaic module according to an embodiment of the present invention is applied in a process in which a robot grasps a first cell from a first conveying device and places the cell on a second conveying device. The method for preparing a photovoltaic module includes the following steps: Step 101: Acquire first compensation data of a first battery cell.

[0028] Specifically, the first compensation data represents a position deviation of the first battery cell on the first transport device.

[0029] The executor of this embodiment is the piezoelectric controller in the piezoelectric micro-motion platform. The piezoelectric controller is used to control the movement of the piezoelectric micro-motion platform in real time, achieve high-precision positioning and trajectory tracking, and process signals from other modules, such as position signals, force sensor signals, etc., to achieve closed-loop control.

[0030] refer to Figure 1 When the first cell is on the first conveyor, i.e., the feeding belt, the piezoelectric controller uses a CCD camera to obtain position information of the first cell on the first conveyor. If there is no deviation, the first cell coincides with the target center position of the first conveyor. If there is deviation, the first cell is offset from the target center position on the first conveyor. This includes an offset in the X direction (the direction of movement of the first conveyor), an offset in the Y direction (perpendicular to the direction of movement of the first conveyor and parallel to the first conveyor), and an offset angle. In this embodiment, the CCD camera is used to obtain position information of the first cell on the first conveyor to determine the position deviation of the first cell on the first conveyor, i.e., first compensation data.

[0031] In some embodiments, the first compensation data is obtained in real time. After the first compensation data is obtained once, the position of the first battery cell on the first transmission device can be adjusted. By obtaining the first compensation data in real time, the position deviation of the first battery cell on the first transmission device can be eliminated as much as possible. However, this deviation cannot be completely eliminated. Therefore, when the robot grasps the first battery cell, the first compensation data of the first battery cell at this time is obtained, thereby providing deviation data for subsequent adjustment of the placement position of the first battery cell on the second transmission device by the robot, thereby improving the accuracy of the deviation adjustment, reducing the error of the battery cell in the negative spacing string welding process, and improving the yield of photovoltaic modules.

[0032] Specifically, the CCD camera uses a circularly polarized light source and sub-pixel edge detection to improve the deviation adjustment in the first transmission device, that is, the static compensation accuracy, to ±0.05mm. The CCD camera obtains the offset angle based on the rotation deviation calculation method (Python) based on principal component analysis, with an angle resolution of 0.05°.

[0033] like Figure 3As shown, it is a flowchart of each sub-step of step 101 of this embodiment. Step 101 is to obtain the first compensation data of the first solar cell, including the following sub-steps: Step 1011, obtain the first image data of the first solar cell on the first transfer device.

[0034] Specifically, the first image data is obtained by a CCD camera using a circularly polarized light source. In this embodiment, circularly polarized light is used as active illumination, and the emitted light is polarized light with a single polarization direction. A rotatable analyzer is set in front of the CCD camera, and the analyzer is rotated to be orthogonal to the polarization direction of the circularly polarized light. By triggering a signal, the circularly polarized light is instantaneously lit within 500 μs, and the CCD camera is exposed for 500 μs in the same frame. By exposing once or multiple times and recording the grayscale at different polarization angles, the first image data with anti-reflection can be obtained.

[0035] Step 1012, extract the first contour image of the first solar cell from the first image data using the Canny edge detection algorithm.

[0036] Specifically, the Canny edge detection algorithm sequentially completes the extraction of the first contour image of the first solar cell through steps such as noise suppression (Gaussian filtering), gradient calculation (amplitude + direction), non-maximum suppression (Non-Maximum Suppression, NMS), double threshold + hysteresis threshold (Hysteresis). Among them, the purpose of noise suppression is to weaken high-frequency noise and prevent misjudging noise as edges; gradient calculation (amplitude + angle) calculates the gradients Gx and Gy in the X and Y directions using a Sobel kernel, the amplitude M(x,y)= , the angle θ(x,y)=arctan(Gy / Gx), and the angle θ(x,y) is quantized into four direction bins of 0°, 45°, 90°, and 135°; non-maximum suppression compares the amplitude M of each pixel with the amplitudes of its two adjacent pixels along the direction of the angle θ(x,y). If the amplitude M of this pixel is not the local maximum, this pixel is set to 0 (trimmed); the double threshold + hysteresis threshold sets a high threshold Th and a low threshold Tl (for example, Tl = 50, Th = 150). If the M corresponding to the pixel ≥ Th, the pixel is a strong edge and this pixel is retained; if the M corresponding to the pixel satisfies: Tl ≤ M < Th, the pixel is a weak edge, and it is only retained when the pixel is connected to a strong edge. When the pixel is not connected to a strong edge, it needs to be suppressed. If the M corresponding to the pixel < Tl, this pixel needs to be suppressed. The first contour image of the first solar cell extracted by the Canny edge detection algorithm is edges = cv2.Canny(image,Tl = 50,Th = 150), which represents all the edges of the image (represented as a pile of lines).

[0037] Step 1013 : extracting the largest connected domain in the first contour image, and determining the center position data of the first battery cell in the largest connected domain.

[0038] Specifically, the maximum connected domain is extracted in the first contour image, that is, in the above-mentioned pile of lines, all connected white pixels (contours) are found, and then the one with the largest area is selected as the final output. The extracted maximum connected domain is contour=find_max_contour(edges).

[0039] After extracting the maximum connected domain, this embodiment obtains the outline of the first battery cell, and then determines the center position data of the first battery cell in the maximum connected domain, thereby obtaining the deviation between the center position data and the target center position in the first transmission device to obtain the first compensation data.

[0040] Step 1014: Obtain first compensation data based on the deviation between the center position data and the target center position in the first transmission device.

[0041] The first compensation data includes a first compensation amount in a first direction (i.e., the X direction), a second compensation amount in a second direction (i.e., the Y direction), and a compensation angle; the first direction is the moving direction of the first transmission device, and the second direction is perpendicular to the first direction and parallel to the surface of the first battery cell placed by the first transmission device.

[0042] For example, taking a 156mm battery cell as an example, the theoretical target position, that is, the target center position in the first transmission device, is target_pos=(belt_x0+15.6,belt_y0), where (belt_x0,belt_y0) represents a reference point in the first transmission device. Subsequently, the first offset ΔX0 in the X direction and the second offset ΔY0 in the Y direction are calculated. ΔX0 and ΔY0 are calculated as follows: (ΔX0, ΔY0)=calculate_offset(contour.center,target_pos). Contour.center is the center position data of the largest connected domain, including position data in the X and Y directions. If the center position data contour.center is (100,200) and the target center position target_pos is (150,250), the center position data needs to be moved 50 units to the right in the X direction and 50 units upward in the Y direction to reach the target center position. The compensation angle is Δθ = pca_orientation(contour) - belt_angle, where contour is the maximum connected domain and belt_angle is the conveyor belt direction, i.e., the moving direction of the first transmission device. The compensation angle Δθ is calculated by principal component analysis (PCA) to calculate the main direction of the contour in the maximum connected domain and the angular difference between the main direction of the contour and the conveyor belt direction.

[0043] Specifically, the robot grabs the first battery cell on the first transmission device based on the first compensation data. The position of the robot grabbing is robot.move_to(belt_x0+ΔX0, belt_y0+ΔY0, Z=5mm, θ=Δθ), which means hovering 5mm on the Z axis (perpendicular to the direction of the first transmission device).

[0044] Step 102: Acquire second compensation data of the first solar cell.

[0045] Specifically, the second compensation data represents a positional deviation between the first battery cell and the second conveying device when the first battery cell reaches the target range of the second conveying device but is not placed on the second conveying device.

[0046] refer to Figure 1When the first cell is located on the second conveyor, i.e., the welding belt, a laser sensor is used to obtain position information of the first cell on the second conveyor. In this embodiment, multiple laser scanners, such as three or four, can be provided. These multiple laser scanners simultaneously receive trigger signals, ensuring that the information obtained by the multiple laser scanners represents multiple perspectives of the same cross-section in physical space. After the robot grasps the first cell, it moves it above the second conveyor, i.e., within the target range of the second conveyor. However, at this point, the first cell has not yet been placed on the second conveyor. Therefore, the position of the first cell on the second conveyor is adjusted in real time using second compensation data detected by the laser sensor. This reduces deviations in cell welding and improves the yield rate of photovoltaic modules.

[0047] like Figure 4 FIG. 1 is a flow chart of the sub-steps of step 102 of this embodiment. Step 102 is obtaining the second compensation data of the first solar cell, and includes the following sub-steps: Step 1021 , when the first cell reaches the target range of the second transmission device and is not placed on the second transmission device, obtain first edge feature data of the first cell and obtain second edge feature data of the second cell on the second transmission device.

[0048] When the first battery cell is placed on the second transmission device, the first battery cell is adjacent to the second battery cell.

[0049] Specifically, obtaining the first edge feature data of the first battery cell is achieved in the following manner: synchronously scanning the first battery cell by at least one laser sensor to obtain first point cloud data; the laser sensor is set on the second transmission device; and edge extraction is performed on the first point cloud data to obtain first edge feature data.

[0050] Specifically, the second edge feature data of the second battery cell located on the second transmission device is obtained by: synchronously scanning the second battery cell with at least one laser sensor to obtain second point cloud data; and performing edge extraction on the second point cloud data to obtain second edge feature data.

[0051] In this embodiment, multiple laser scanners may be provided, for example, 3 or 4, and the multiple laser scanners receive trigger signals simultaneously, ensuring that the information acquired by the multiple laser scanners is multiple perspectives of the same cross section in physical space. Specifically, the first and second point cloud data can be acquired in the following manner: each laser scanner performs internal sampling at a frequency of, for example, 5 kHz, which means that five contour points can be generated within every 1 ms trigger cycle. Savitzky-Golay filtering is then performed to suppress laser speckle and CMOS (Complementary Metal-Oxide-Semiconductor) quantization noise while preserving sub-pixel steps. Savitzky-Golay filtering prevents over-smoothing of minor defects and amplifies high-frequency noise. A calibration matrix conversion is then performed, obtaining, for example, a 4×4 homogeneous matrix, which converts the local coordinates of each laser sensor to world coordinates. Finally, multiple sets of aligned contours are assembled into a complete cross-section, and then fine-tuned using nearest neighbor averaging or iterative closest point (ICP) based on a KD-Tree (k-dimensional tree) to eliminate residual extrinsic parameter errors, thereby obtaining the first and second point cloud data.

[0052] After acquiring the first point cloud data and the second point cloud data, this embodiment performs edge feature extraction on the first point cloud data to obtain first edge feature data, and performs edge feature extraction on the second point cloud data to obtain second edge feature data. In this embodiment, both the first edge feature data and the second edge feature data can be upper edge point sets.

[0053] Step 1022 : Obtain an optimal offset between the first battery cell and the second battery cell according to the first edge feature data and the second edge feature data.

[0054] like Figure 5 FIG. 1 is a flow chart of the sub-steps of step 1022 of this embodiment. Step 1022 is to obtain the optimal offset between the first battery cell and the second battery cell based on the first edge feature data and the second edge feature data, and includes the following sub-steps: Step 10221: Acquire a first edge curvature of the first battery cell according to the first edge feature data.

[0055] Step 10222: Obtain a second edge curvature of the second battery cell according to the second edge feature data.

[0056] Step 10223: Use a curvature matching algorithm to obtain the optimal offset between the first edge curvature and the second edge curvature.

[0057] The first edge feature data is set as upper_edge=extract_edge(point_cloud, direction='top'), where upper_edge is a two-dimensional point set representing the contour points of the upper edge of the first battery cell. Afterwards, the edge curvature κ_curr of the first battery cell, i.e., the upper edge curvature, is calculated, for example, κ_curr=compute_curvature(upper_edge); wherein, the edge curvature of the first battery cell needs to be acquired in real time, and the edge curvature of the second battery cell is also acquired in the same manner, but the timing of acquiring the edge curvature of the second battery cell is different. In this embodiment, the second edge feature data of the second battery cell can be acquired in advance when the second battery cell is placed on the second transmission device, and the edge curvature of the second battery cell is acquired based on the second edge feature data and stored in advance. When the edge curvature of the first battery cell is subsequently acquired, the edge curvature κ_prev of the second battery cell in the historical record is directly loaded from the file or database, for example, κ_prev=load_prev_battery_curvature().

[0058] Afterwards, the optimal offset Δd=curvature_matching(κ_curr,κ_prev) between the edge curvatures of the first cell and the second cell is calculated based on a curvature matching algorithm. The curvature matching algorithm usually determines the alignment position of two cells based on the similarity of curvature.

[0059] Step 1023 : Acquire second compensation data according to the first edge feature data, the target position on the second transmission device, and the optimal offset.

[0060] The second compensation data includes a third compensation amount in a third direction (the X direction of the second transmission device) and a fourth compensation amount in a fourth direction (the Y direction of the second transmission device); the third direction is the moving direction of the second transmission device, and the fourth direction is perpendicular to the third direction and parallel to the surface of the second transmission device on which the second battery cell is placed.

[0061] like Figure 6 FIG. 1 is a flow chart of the sub-steps of step 1023 of this embodiment. Step 1023 is to obtain the second compensation data based on the first edge feature data, the target position on the second transmission device, and the optimal offset, and includes the following sub-steps: Step 10231: extract first position information of any target edge point from the first edge feature data.

[0062] Step 10232: extract second position information corresponding to the target edge point in the target position on the second transmission device.

[0063] Step 10233: Obtain second compensation data according to the first position information, the second position information, the optimal offset, and the compensation angle.

[0064] In this embodiment, in the process of obtaining the second compensation data based on the first edge feature data, the target position on the second transmission device, and the optimal offset, the first position information (edge_position[0], edge_position[1]) of any target edge point is extracted from the first edge feature data, and the second position information (reference_position[0], reference_position[1]) corresponding to the target edge point is extracted from the target position on the second transmission device. Then, the second compensation data return Vector (ΔX, ΔY) is obtained based on the first position information, the second position information, the optimal offset, and the compensation angle, wherein the third compensation amount ΔX in the third direction is equal to edge_position[0]-reference_position[0]+Δd×cos(θ), and the fourth compensation amount ΔY in the fourth direction is equal to edge_position[1]-reference_position[1]+Δd×sin(θ), where θ is the offset angle in the first compensation data.

[0065] Step 103 : acquiring target compensation data according to the first compensation data and the second compensation data, so as to control the robot arm to adjust the position of the first battery cell on the second transmission device based on the target compensation data.

[0066] like Figure 7 FIG. 1 is a flow chart of the sub-steps of step 103 of this embodiment. Step 103 is to obtain target compensation data according to the first compensation data and the second compensation data, and includes the following sub-steps: Step 1031 : Determine a first weight of the first compensation data and a second weight of the second compensation data according to an exponential decay weight.

[0067] The first weight is proportional to the exponential decay weight, and the second weight is inversely proportional to the exponential decay weight.

[0068] Step 1032: Obtain target compensation data according to the first compensation data, the second compensation data, the first weight, and the second weight.

[0069] The first compensation data of this embodiment is static compensation, which is applied to the entire process of the robot carrying the first battery cell. When the robot grabs the first battery cell on the first transmission device, the robot performs static compensation based on the first compensation data; the second compensation data is dynamic compensation, which is only activated at the end of placing the cell (for example, 5mm from the height of the welding belt), that is, when the first battery cell reaches the target range of the second transmission device and is not placed on the second transmission device, the second compensation data is obtained.

[0070] This embodiment implements a dynamic coordination strategy at the film placement end of the manipulator, spatially fuses the first compensation data and the second compensation data, and obtains the first weight of the first compensation data and the second weight of the second compensation data respectively. The first compensation data and the second compensation data are used to calculate the target compensation data of the manipulator according to their respective weights. The target compensation data are ΔXfinal and ΔYfinal, ΔXfinal=α×ΔX0+(1-α)×ΔX, ΔYfinal=α×ΔY0+(1-α)×ΔY, where α is the first weight, 1-α is the second weight, and α=e (-t / τ) , τ is the exponential decay weight, for example, τ=0.1s.

[0071] In some embodiments, when the deviation between the first compensation data and the second compensation data is greater than a preset threshold, it indicates that the compensation deviation obtained by the manipulator is relatively large, and an emergency hovering needs to be triggered for manual review; for example, when the difference between ΔX0 in the first compensation data and ΔX in the second compensation data satisfies |ΔX-ΔX0|>0.2mm, an emergency hovering is triggered for manual review.

[0072] This embodiment detects the placement position of the robot's end in real time and adjusts it until the robot places the first cell on the second conveyor. This reduces cell deviation during the negative-pitch string soldering process and improves the yield rate of photovoltaic modules. After the robot places the first cell on the second conveyor, it continues to grab the next cell from the first conveyor and repeats the above steps.

[0073] like Figure 8 FIG. 1 is another flow chart of the method for preparing a photovoltaic module according to the present embodiment. The method for preparing a photovoltaic module according to the present embodiment includes the following steps: Step 201: Acquire first compensation data of a first battery cell.

[0074] Step 202: Acquire second compensation data of the first solar cell.

[0075] Step 203: Acquire third compensation data of the first battery cell.

[0076] This embodiment further acquires third compensation data, wherein the third compensation data includes at least one of the following compensations: thermal expansion compensation, vibration compensation, and belt slip compensation.

[0077] Specifically, the thermal expansion compensation Δ_thermal = (16.5e-6) × L0 × (Tsensor-T0), where 16.5e-6 is the thermal expansion coefficient of the material, which represents the relative elongation of the belt material per degree Celsius temperature change. L0 is the initial length of the belt, Tsensor is the temperature currently measured by the sensor, and T0 is the reference temperature, which is generally the temperature during belt calibration or initial operation.

[0078] Vibration compensation is calculated using the jerk measured by a MEMS (Micro-Electro-Mechanical Systems) accelerometer. The vibration compensation is calculated as Δ_vibration = 0.003 × jerk, where 0.003 is the vibration compensation coefficient and jerk is the jerk, which represents the rate of change of acceleration.

[0079] The belt slip compensation is calculated by the speed difference fed back by the encoder. The belt slip compensation is Δ_belt. The belt slip compensation Δ_belt = 0.015×(v encoder -v setpoint ), 0.015 is the belt slip compensation coefficient, v encoder is the actual speed measured by the encoder, v setpoint is the set target speed.

[0080] Finally, the third compensation data Δcomp=Δ_thermal+Δ_vibration+Δ_belt is obtained.

[0081] Step 204 , obtaining target compensation data according to the first compensation data, the second compensation data, and the third compensation data, so as to control the robot to adjust the position of the first battery cell on the second transmission device based on the target compensation data.

[0082] Step 201 and step 202 are substantially the same as the above-mentioned step 101 and step 102, and will not be described again here to avoid repetition.

[0083] This embodiment implements a dynamic coordination strategy at the film placement end of the manipulator, spatially fuses the first compensation data, the second compensation data, and the third compensation data, obtains a first weight of the first compensation data, adds the second compensation data and the third compensation data as one compensation data, obtains a second weight of the sum of the second compensation data and the third compensation data, and calculates the target compensation data ΔXfinal and ΔYfinal of the manipulator according to their respective weights. The target compensation data ΔXfinal and ΔYfinal are calculated as follows: ΔXfinal=α×ΔX0+(1-α)×(ΔX+Δcomp), ΔYfinal=α×ΔY0+(1-α)×(ΔY+Δcomp), where α is the first weight, 1-α is the second weight, and α=e (-t / τ) , τ is the exponential decay weight, for example, τ=0.1s.

[0084] As shown in the following table, the technical parameters of the core modules in the laser dynamic correction system of this embodiment are as follows: laser sensor, piezoelectric micro-motion platform, piezoelectric controller, temperature sensor, and vibration sensor.

[0085]

[0086] This embodiment uses laser dynamic positioning technology and common optical path laser triangulation at the robotic arm's placement end to eliminate vibration interference, achieving a resolution of ±0.01mm, 10 times that of traditional visual inspection. This embodiment also collaboratively compensates for multiple sources of wafer placement errors, including equipment baseline, cutting tolerance, thermal deformation, vibration, material creep, conveyor belt fluctuation, and residual stress from installation, eliminating the impact of these errors on wafer placement accuracy. This embodiment uses dynamic closed-loop deviation correction to achieve millimeter-level real-time position correction at the end of wafer placement (for example, at a height of 0.5mm from the welding belt), overcoming the limitations of existing open-loop control. The piezoelectric micro-motion platform provides real-time response. The closed-loop control bandwidth of this nano-scale micro-motion platform, based on the inverse piezoelectric effect, exceeds 500Hz, 20 times that of mechanical actuators. Furthermore, this embodiment uses the piezoelectric micro-motion platform to provide the handling arm with fine-tuning capabilities in the Y direction, overcoming the hardware limitations of existing equipment. This embodiment also integrates multi-sensor data, fusing laser profile data with belt encoder signals, to compensate for transmission vibration. This reduces cell deviation during negative-pitch string soldering and improves the yield rate of photovoltaic modules.

[0087] The following table shows a comparison of errors of multiple error sources between this embodiment and the prior art solution.

[0088]

[0089] It can be seen that compared with the existing solution, this embodiment reduces the errors of multiple error sources, thereby reducing the overall comprehensive error. The comprehensive error is reduced from the original ±0.5mm to ±0.038mm, meeting the product design requirement of stacking spacing of -0.4mm±0.1mm, and improving the yield of photovoltaic modules.

[0090] The following table shows a comparison of the technical effects of this embodiment and the existing solution.

[0091]

[0092] It can be seen that compared with the existing solution of serial soldering CCD film placement system technology, this embodiment reduces the stacking spacing accuracy from ±0.28mm to about ±0.038mm, reduces the film leakage defect rate from 62.5% to about 0%, and reduces the temperature slip effect from 0.2mm / 10℃ to 0.015mm / 10℃. In addition, the device beat delay of this embodiment is less than 10ms, which is negligible.

[0093] An embodiment of the present application further relates to a photovoltaic module, which is prepared by the above-mentioned method for preparing a photovoltaic module.

[0094] The photovoltaic module of this embodiment is manufactured by the above-mentioned method for manufacturing a photovoltaic module, thereby reducing the deviation of the battery cells during the negative pitch string welding process and improving the yield rate of the photovoltaic module.

[0095] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A method for preparing a photovoltaic module, characterized in that: include: Acquiring first compensation data of the first battery cell during a process in which the robot grabs the first battery cell from the first conveying device and places the first battery cell on the second conveying device; The first compensation data represents a position deviation of the first battery cell on the first transmission device; Obtaining second compensation data for the first battery cell; the second compensation data indicating a positional deviation between the first battery cell and the second transmission device when the first battery cell reaches a target range of the second transmission device and is not placed on the second transmission device; Target compensation data is acquired according to the first compensation data and the second compensation data, so as to control the robot to adjust the position of the first battery cell placed on the second transmission device based on the target compensation data.

2. The method for preparing a photovoltaic module according to claim 1, wherein: The obtaining of first compensation data of the first battery cell includes: Acquire first image data of the first cell on the first transmission device; the first image data is acquired by a CCD camera using a circularly polarized light source; extracting a first contour image of the first cell from the first image data using a Canny edge detection algorithm; Extracting a maximum connected domain from the first contour image, and determining center position data of the first battery cell in the maximum connected domain; The first compensation data is obtained based on the deviation between the center position data and the target center position in the first transmission device; wherein the first compensation data includes a first compensation amount in a first direction, a second compensation amount in a second direction, and a compensation angle; the first direction is the moving direction of the first transmission device, and the second direction is perpendicular to the first direction and parallel to the surface of the first transmission device on which the first battery cell is placed.

3. The method for preparing a photovoltaic module according to claim 2, wherein: The obtaining of second compensation data of the first battery cell includes: When the first battery cell reaches a target range of the second transmission device and is not placed on the second transmission device, obtaining first edge feature data of the first battery cell and obtaining second edge feature data of a second battery cell located on the second transmission device; when the first battery cell is placed on the second transmission device, the first battery cell is adjacent to the second battery cell; Obtaining an optimal offset between the first battery cell and the second battery cell according to the first edge feature data and the second edge feature data; The second compensation data is acquired according to the first edge feature data, the target position on the second transmission device, and the optimal offset.

4. The method for preparing a photovoltaic module according to claim 3, wherein: The obtaining of first edge feature data of the first battery cell includes: The first point cloud data is obtained by synchronously scanning the first cell sheet with at least one laser sensor; the laser sensor is arranged on the second transmission device; Performing edge extraction on the first point cloud data to obtain the first edge feature data; The acquiring second edge feature data of the second battery cell located on the second transmission device includes: Synchronously scanning the second cell sheet by at least one of the laser sensors to obtain second point cloud data; Perform edge extraction on the second point cloud data to obtain the second edge feature data.

5. The method for preparing a photovoltaic module according to claim 3, wherein: The obtaining the optimal offset between the first battery cell and the second battery cell according to the first edge feature data and the second edge feature data includes: Acquire a first edge curvature of the first battery cell according to the first edge feature data; Acquire a second edge curvature of the second battery cell according to the second edge feature data; A curvature matching algorithm is used to obtain the optimal offset between the first edge curvature and the second edge curvature.

6. The method for preparing a photovoltaic module according to claim 3, wherein: The acquiring the second compensation data according to the first edge feature data, the target position on the second transmission device, and the optimal offset includes: Extracting first position information of any target edge point from the first edge feature data; extracting second position information corresponding to the target edge point at the target position on the second transmission device; The second compensation data is obtained according to the first position information, the second position information, the optimal offset, and the compensation angle; wherein the second compensation data includes a third compensation amount in a third direction and a fourth compensation amount in a fourth direction; the third direction is the moving direction of the second transmission device, and the fourth direction is perpendicular to the third direction and parallel to the surface of the second transmission device on which the second battery cell is placed.

7. The method for preparing a photovoltaic module according to claim 1, wherein: The acquiring target compensation data according to the first compensation data and the second compensation data includes: determining a first weight of the first compensation data and a second weight of the second compensation data according to an exponential decay weight; wherein the first weight is proportional to the exponential decay weight, and the second weight is inversely proportional to the exponential decay weight; The target compensation data is acquired according to the first compensation data, the second compensation data, the first weight, and the second weight.

8. The method for preparing a photovoltaic module according to claim 1, wherein: The method further comprises: Obtaining third compensation data of the first battery cell; the third compensation data includes at least one of the following compensations: thermal expansion compensation, vibration compensation, and belt slip compensation; The acquiring target compensation data according to the first compensation data and the second compensation data includes: Target compensation data is acquired according to the first compensation data, the second compensation data, and the third compensation data.

9. The method for preparing a photovoltaic module according to claim 8, wherein: The acquiring target compensation data according to the first compensation data, the second compensation data, and the third compensation data includes: Acquire fourth compensation data according to the second compensation data and the third compensation data; determining a third weight of the first compensation data and a fourth weight of the fourth compensation data according to an exponential decay weight; wherein the third weight is proportional to the exponential decay weight, and the fourth weight is inversely proportional to the exponential decay weight; The target compensation data is acquired according to the first compensation data, the fourth compensation data, the third weight, and the fourth weight.

10. A photovoltaic module, characterized in that: The photovoltaic module is prepared by the method for preparing a photovoltaic module according to any one of claims 1 to 9.

Images