Resistance test system

Abstract

The utility model discloses a resistance test system, comprising a light source used for emitting light to a cell to be tested; the grating is located between the imaging device and the battery piece to be detected; the grating is used for shielding part of light emitted by the light source; the grating comprises at least two gratings, and the patterns of the at least two gratings are complementary patterns; the imaging device is used for respectively acquiring at least two first gray value images of the battery piece to be detected under the condition that the at least two optical gratings shield part of light rays emitted by the light source; under the condition that the light emitted by the light source is not shielded, the imaging device is also used for acquiring a second gray value image of the battery piece to be detected; the control module is electrically connected with the imaging device and the light source, and the light source is located on one side of the imaging device. According to the utility model, the non-contact measurement of the resistance of any metalized pattern battery piece can be realized, the universality and compatibility are good, and the accuracy of the test result is improved.

Description

Technical Field

[0001] This utility model relates to the field of resistance testing technology, and in particular to a resistance testing system. Background Technology

[0002] In related technologies, to test the resistance of solar cells, it is usually necessary to form a circuit by contacting the solar cell with a probe. However, this testing method is prone to causing breakage when the probe presses down on the solar cell, the probe is a consumable and increases costs, the shadow cast by the probe can cause interference, and the solar cell pattern needs corresponding solder pads to form a good contact with the probe, which increases the cost of the solar cell. To solve the above problems, the resistance of the solar cell under test is currently measured by a non-contact method, but the non-contact measurement method will affect the accuracy of the measurement results. Utility Model Content

[0003] This invention provides a resistance testing system that enables non-contact measurement of the resistance of any metallized patterned battery cell. It has good versatility and compatibility, and can improve the accuracy of test results.

[0004] According to one aspect of the present invention, a resistance testing system is provided, comprising:

[0005] Light source, used to emit light onto the battery cell under test;

[0006] An imaging device and a grating are provided, with the grating located between the imaging device and the battery cell under test. The grating is used to block part of the light emitted by the light source. The grating includes at least two gratings, and the patterns of the at least two gratings are complementary. When at least two gratings block part of the light emitted by the light source, the imaging device is used to acquire at least two first grayscale images of the battery cell under test. When the light emitted by the light source is not blocked, the imaging device is also used to acquire a second grayscale image of the battery cell under test.

[0007] The control module is electrically connected to the imaging device and the light source, with the light source located on one side of the imaging device.

[0008] Based on the above embodiments, optionally, at least two first grayscale value images are complementary;

[0009] The resistance testing system also includes:

[0010] Drive unit;

[0011] With the positions of the light source and the cell under test fixed, the driving device is electrically connected to the control module and connected to at least two gratings, and the driving device is used to drive the at least two gratings to move; or, with the positions of the light source and the gratings fixed, the driving device is connected to the cell under test, and the driving device is used to drive the cell under test to move.

[0012] Based on the above embodiments, optionally, the driving device includes a grating driving device and a battery cell driving device;

[0013] The grating drive device includes a servo motor or a stepper motor;

[0014] The cell drive unit includes a conveyor belt.

[0015] Based on the above embodiments, optionally, the imaging device includes a first imaging device, a second imaging device, and a third imaging device; the light source includes a first light source, a second light source, and a third light source; the grating includes a first grating and a second grating, wherein the patterns of the first grating and the second grating are complementary patterns.

[0016] The control module is electrically connected to the first imaging device, the second imaging device, the third imaging device, the first light source, the second light source, and the third light source. The first light source is located on one side of the first imaging device, and the first imaging device is directly opposite the first grating. The second light source is located on one side of the second imaging device, and the second imaging device is directly opposite the second grating. The third light source is located on one side of the third imaging device, and the position directly opposite the third imaging device is not obstructed by the first grating or the second grating.

[0017] The driving device is used to drive the battery cell under test to move to the side of the first grating away from the first imaging device. When the first grating blocks part of the light emitted by the first light source, the first imaging device is used to acquire the first gray value of the battery cell under test.

[0018] The driving device is used to drive the battery cell under test to move to the side of the second grating away from the second imaging device. When the second grating blocks part of the light emitted by the second light source, the second imaging device is used to acquire the first gray value of the battery cell under test as a second image.

[0019] The driving device is used to drive the battery cell under test to move to the side facing the third imaging device. When the light emitted by the third light source is not blocked, the third imaging device is used to acquire the second grayscale image of the battery cell under test.

[0020] Based on the above embodiments, optionally, the grating includes a first grating and a second grating, wherein the patterns of the first grating and the second grating are complementary patterns;

[0021] The driving device is used to drive the first grating to move between the imaging device and the battery cell under test. When the first grating blocks part of the light emitted by the light source, the imaging device is used to acquire the first gray value of the battery cell under test as a first image.

[0022] The driving device is used to drive the second grating to move between the imaging device and the battery cell under test. When the second grating blocks part of the light emitted by the light source, the imaging device is used to acquire a second image of the first gray value of the battery cell under test.

[0023] The driving device drives the first grating and the second grating to move between the imaging device and the battery cell under test, so that the first grating and the second grating are not obstructed. When the light emitted by the light source is not blocked, the imaging device is used to acquire the second grayscale image of the battery cell under test.

[0024] Based on the above embodiments, optionally, the driving device is used to drive the first grating and the second grating to move along a first direction, or the driving device is used to drive the first grating and the second grating to move along a second direction;

[0025] The first direction and the second direction intersect each other.

[0026] Based on the above embodiments, optionally, the resistance testing system further includes:

[0027] A rotating device, on which at least two gratings are located; a driving device is used to drive the movement of at least two gratings via the rotating device.

[0028] Based on the above embodiments, optionally, the grating includes a first grating, a second grating, and a third grating, wherein the patterns of the first grating, the second grating, and the third grating are complementary patterns;

[0029] The driving device is used to drive the first grating to move between the imaging device and the battery cell under test through the rotating device. When the first grating blocks part of the light emitted by the light source, the imaging device is used to acquire the first gray value of the battery cell under test as a first image.

[0030] The driving device is used to drive the second grating to move between the imaging device and the battery cell under test through the rotating device. When the second grating blocks part of the light emitted by the light source, the imaging device is used to acquire the first gray value of the battery cell under test as a second image.

[0031] The driving device is used to drive the third grating to move between the imaging device and the battery cell under test through the rotating device. When the third grating blocks part of the light emitted by the light source, the imaging device is used to acquire the first gray value third image of the battery cell under test.

[0032] The driving device drives the first grating, the second grating, and the third grating to move between the imaging device and the battery cell under test without the first grating, the second grating, and the third grating obstructing the light emitted by the light source. The imaging device is used to acquire the second grayscale image of the battery cell under test when the light emitted by the light source is not blocked.

[0033] Optionally, based on the above embodiments, the light source may include a laser light source;

[0034] The resistance testing system also includes a laser homogenization device, which is used to homogenize the light emitted by the laser source.

[0035] Based on the above embodiments, optionally, the imaging device is a camera; the camera includes a grayscale camera or a charge-coupled device camera.

[0036] The resistance testing system provided by this embodiment of the utility model includes: a light source for emitting light onto a battery cell under test; an imaging device and a grating, the grating being located between the imaging device and the battery cell under test; the grating being used to block part of the light emitted by the light source; the grating including at least two gratings, the patterns of the at least two gratings being complementary patterns; when at least two gratings block part of the light emitted by the light source, the imaging device is used to acquire at least two first grayscale value images of the battery cell under test respectively; when the light emitted by the light source is not blocked, the imaging device is also used to acquire a second grayscale value image of the battery cell under test; a control module electrically connected to the imaging device and the light source, the light source being located on one side of the imaging device; the control module is used to determine the resistance of the battery cell under test based on the second grayscale value image and the at least two first grayscale value images. This utility model embodiment uses complementary gratings to block the light source respectively. Multiple complementary gratings can be arbitrarily designed according to the main grating pattern and / or fine grating line pattern of the battery cell under test. This can solve the problem that the motion accuracy of a single grating cannot accurately match the battery cell under test. It also avoids large errors in image data caused by a single grating pattern. It realizes non-contact measurement of the resistance of battery cells with arbitrary metallized patterns, has good versatility and compatibility, and improves the accuracy of test results.

[0037] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure of a resistance testing system provided in an embodiment of this utility model.

[0040] Figure 2 This is a schematic diagram of a complementary grating provided in an embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of another complementary grating provided in this embodiment of the present invention.

[0042] Figure 4 This is a schematic diagram of another resistance testing system provided in this embodiment of the present invention.

[0043] Figure 5 This is a schematic diagram of another resistance testing system provided in this embodiment of the present invention.

[0044] Figure 6 This is a schematic diagram of another resistance testing system provided in this embodiment of the present invention. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0046] It should be noted that the terms "first," "second," etc., used in this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] Currently, the resistance testing method for solar cells uses a single-pattern motion grating. This grating is used to repeatedly move and obscure areas to obtain a complete composite image of the solar cell. However, using a single-pattern motion grating presents several problems. First, because the servo motor's movement direction is unidirectional, only a simple, repetitive motion grating structure can be used to obtain a complete composite image. This limits the design space for the grating's cutout and obscuring areas, making it impossible to design a reasonable grating based on the main grid or fine grid line pattern of the solar cell, thus affecting the accuracy of the test results. Second, the motion grating is usually driven by a servo motor, and the servo motor's movement precision limits the completeness of the composite image, leading to significant data errors and affecting the stability of the test results.

[0048] To address the aforementioned problems, this invention provides a resistance testing system. Figure 1 This is a schematic diagram of the structure of a resistance testing system provided in an embodiment of this utility model, for reference. Figure 1 The resistance testing system includes:

[0049] Light source 20, used to emit light to the battery cell 10 under test;

[0050] An imaging device 30 and a grating 40 are provided, with the grating 40 located between the imaging device 30 and the battery cell 10 under test. The grating 40 is used to block part of the light emitted by the light source 20. The grating 40 includes at least two gratings 40, and the patterns of the at least two gratings 40 are complementary. When at least two gratings 40 block part of the light emitted by the light source 20, the imaging device 30 is used to acquire at least two first grayscale images of the battery cell 10 under test. When the light emitted by the light source 20 is not blocked, the imaging device 30 is also used to acquire a second grayscale image of the battery cell 10 under test.

[0051] The control module 50 is electrically connected to the imaging device 30 and the light source 20, with the light source 20 located on one side of the imaging device 30.

[0052] The tested solar cell 10 may include a solar cell. The light source 20 may be a laser light source or an LED light source, and can be any one of a point light source, line light source, or area light source. The light source 20 is located to one side of the imaging device 30, and not between the imaging device 30 and the tested solar cell 10, to avoid the light source 20 obstructing the imaging device 30. The imaging device 30 may be a grayscale camera, for example, a charge-coupled device (CCD) camera. The grating 40 includes at least two gratings 40, which may be moving gratings or fixed gratings. The materials of the gratings 40 include, but are not limited to, high-transparency glass, plastic, metal, alloy, wood, etc.

[0053] The grating 40 includes at least two gratings 40, the patterns of the at least two gratings 40 are complementary, and the combined patterns of the at least two gratings 40 can completely cover the entire solar cell 10 under test. For example, Figure 2 This is a schematic diagram of a complementary grating provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of another complementary grating provided in an embodiment of the present invention, with reference to... Figure 2 and Figure 3 The patterns of the first grating 41 and the second grating 42 are complementary patterns. The first grating 41 and the second grating 42 are complementary gratings, that is, the cutout area of ​​the first grating 41 is complementary to the cutout area of ​​the second grating 42, and the occlusion area of ​​the first grating 41 is complementary to the occlusion area of ​​the second grating 42. Figure 2 The center is a striped grating. Figure 2 The black baffle 03 in the image can be made of metal. Figure 3 The center is a square-shaped grating. Figure 3 The transparent area 01 is made of high-transparency acrylic sheet, and the black shielding area 02 is made of black tape. The number of gratings 40 can be set according to the test requirements, but at least two gratings 40 must have complementary patterns. That is, if the grating 40 includes a first grating 41 and a second grating 42, then the patterns of the first grating 41 and the second grating 42 are complementary patterns; if the grating 40 includes a first grating 41, a second grating 42, and a third grating, then the patterns of the first grating 41, the second grating 42, and the third grating are complementary patterns. This utility model does not impose a specific limit on the number of gratings.

[0054] The first grayscale image is the grayscale image of the battery cell 10 under test acquired by the imaging device 30 when the grating 40 blocks part of the light emitted by the light source 20. The second grayscale image is the grayscale image of the battery cell 10 under test acquired by the imaging device 30 when the light emitted by the light source 20 is not blocked.

[0055] Specifically, the control module 50 is used to determine the resistance of the battery cell 10 under test based on the second grayscale image and at least two first grayscale images. For example, by controlling the movement of at least two gratings 40, the control module 50 can acquire first grayscale images under different occlusion conditions and a second grayscale image without occlusion. The control module 50 can superimpose the grayscale values ​​of the at least two first grayscale images under different occlusion conditions according to their corresponding pixels to form a composite image; then, the control module 50 calculates the grayscale values ​​of the composite image and the second grayscale image without occlusion to obtain grayscale data. A known stable current is applied to the battery cell under test. The current magnitude should be selected according to the specifications of the battery cell and the measurement requirements, generally within the operating current range of the battery cell. The grayscale data can be converted into actual temperature values ​​based on the calibration data of the thermal imager. Different thermal imagers have different conversion formulas or calibration curves, which can usually be obtained through the instrument's instruction manual or related software. Observe the thermal image to find areas with higher temperatures on the battery cell under test; these areas usually correspond to parts with higher resistance. Since heat is generated when current flows through a resistor, according to Joule's law Q = I... 2Rt (where Q is heat, I is current, R is resistance, and t is time) represents the resistance. The higher the resistance, the more heat is generated, and the higher the temperature. Analyzing the temperature distribution of hotspot areas allows us to calculate the average or highest temperature of the area to represent the degree of heat generation. Simultaneously, the area of ​​the hotspot area is measured to facilitate subsequent resistance estimation. A heat conduction model is established based on the material properties, geometry, and heat dissipation conditions of the solar cell. This model describes the relationship between the heat generated when current passes through the solar cell under test, its resistance, and temperature. For example, the finite element method can be used to build the model, dividing the solar cell under test into multiple small units and calculating the heat generation and transfer in each unit. Based on the established thermal model and the measured temperature data, the resistance of the solar cell is estimated through inversion calculation. Specifically, the known current, temperature, and other relevant parameters are substituted into the thermal model equations, and the resistance value is solved until a resistance value meeting the accuracy requirements is obtained. This allows for non-contact resistance testing of the solar cell under test, eliminating the need for probes that could cause breakage, eliminating probe shadow interference, avoiding probe consumption, and eliminating the need for corresponding solder pads for the probes, thus reducing costs. Light emitted from the light source 20 illuminates the battery cell 10 under test, causing it to absorb the light and emit light. The imaging device 30 can acquire a grayscale image of the battery cell 10. At least two gratings 40 block the light source 20, and the imaging device 30 obtains at least two first grayscale images. By blocking the light source 20 with at least two complementary gratings 40, multiple complementary gratings 40 can be arbitrarily designed according to the main grating pattern and / or fine grating line pattern of the battery cell 10 under test. This solves the problem that the motion precision of a single grating cannot accurately match the battery cell under test, avoids large errors in image data caused by a single grating pattern, and enables non-contact measurement of the resistance of battery cells with arbitrary metallized patterns. It has good versatility and compatibility, thereby improving the accuracy of the test results.

[0056] The resistance testing system provided by this embodiment of the present invention includes: a light source 20, which emits light to a battery cell 10 under test; an imaging device 30 and a grating 40, the grating 40 being located between the imaging device 30 and the battery cell 10 under test; the grating 40 being used to block part of the light emitted by the light source 20; the grating 40 includes at least two gratings 40, the patterns of the at least two gratings 40 being complementary patterns; when at least two gratings 40 block part of the light emitted by the light source 20, the imaging device 30 is used to acquire at least two first grayscale value images of the battery cell 10 under test respectively; when the light emitted by the light source 20 is not blocked, the imaging device 30 is also used to acquire a second grayscale value image of the battery cell 10 under test; and a control module 50, which is electrically connected to the imaging device 30 and the light source 20, the light source 20 being located on one side of the imaging device 30; the control module 50 is used to determine the resistance of the battery cell 10 under test based on the second grayscale value image and the at least two first grayscale value images. This utility model embodiment uses complementary gratings 40 to block the light source 20 respectively. Multiple complementary gratings 40 can be arbitrarily designed according to the main grating pattern and / or fine grating line pattern of the battery cell 10 under test. This can solve the problem that the motion accuracy of a single grating cannot accurately match the battery cell under test, and avoid large errors in image data caused by a single pattern of grating 40. It realizes non-contact measurement of the resistance of battery cells with arbitrary metallized patterns, and has good versatility and compatibility, thereby improving the accuracy of test results.

[0057] Based on the above embodiments, optionally, at least two first grayscale images are complementary.

[0058] Among them, the patterns of at least two gratings 40 are complementary patterns. By blocking part of the light emitted by the light source 20 through at least two gratings, the imaging device 30 acquires at least two first grayscale value images that are complementary images.

[0059] Optionally, the resistance testing system further includes: a driving device; when the positions of the light source and the cell under test are fixed, the driving device is electrically connected to the control module, the driving device is connected to at least two gratings, and the driving device is used to drive the movement of at least two gratings; or, when the positions of the light source and the gratings are fixed, the driving device is connected to the cell under test, and the driving device is used to drive the movement of the cell under test.

[0060] The driving device can be used to drive the grating or the battery cell under test to move. For example, the driving device may include a motor or a transmission mechanism. The grating can be electrically connected to the motor, and the battery cell under test can be fixedly connected to the transmission mechanism. The motor drives the grating to move, and the transmission mechanism drives the battery cell under test to move. The driving device drives the grating or the battery cell under test. The driving method is simple and easy to implement.

[0061] Based on the above embodiments, optionally, the driving device includes a grating driving device and a battery cell driving device; the grating driving device includes a servo motor or a stepper motor; the battery cell driving device includes a conveyor belt.

[0062] The grating drive unit is used to move the grating. The cell drive unit is used to move the cell. Servo motors or stepper motors offer high stability and efficiency; the conveyor belt also includes a motor, which drives the conveyor belt's movement. The conveyor belt has a lower cost and can be configured according to requirements.

[0063] Optional, Figure 4 This is a schematic diagram of another resistance testing system provided in this embodiment of the present invention, for reference. Figure 4 The imaging device includes a first imaging device 31, a second imaging device 32 and a third imaging device 33; the light source includes a first light source 21, a second light source 22 and a third light source 23; the grating includes a first grating 41 and a second grating 42, the patterns of the first grating 41 and the second grating 42 are complementary patterns.

[0064] The control module 50 is electrically connected to the first imaging device 31, the second imaging device 32, the third imaging device 33, the first light source 21, the second light source 22, and the third light source 23. The first light source 21 is located on one side of the first imaging device 31, and the first imaging device 31 is directly opposite the first grating 41. The second light source 22 is located on one side of the second imaging device 32, and the second imaging device 32 is directly opposite the second grating 42. The third light source 23 is located on one side of the third imaging device 33, and the position directly opposite the third imaging device 33 is not obstructed by the first grating 41 or the second grating 42.

[0065] The driving device 60 is used to drive the battery cell 10 under test to move to the side of the first grating 41 away from the first imaging device 31. When the first grating 41 blocks part of the light emitted by the first light source 21, the first imaging device 31 is used to acquire the first gray value first image of the battery cell 10 under test.

[0066] The driving device 60 is used to drive the battery cell 10 under test to move to the side of the second grating 42 away from the second imaging device 32. When the second grating 42 blocks part of the light emitted by the second light source 22, the second imaging device 32 is used to acquire the first gray value second image of the battery cell 10 under test.

[0067] The driving device 60 is used to drive the battery cell 10 under test to move to the side directly opposite the third imaging device 33. When the light emitted by the third light source 23 is not blocked, the third imaging device 33 is used to acquire the second grayscale image of the battery cell 10 under test.

[0068] The drive unit 60 can be a conveyor belt, which moves the battery cell 10 under test. Figure 4 In this system, there is one control module 50, three light sources, three imaging devices, and two gratings. The first light source 21, the second light source 22, and the third light source 23 are the same. The first imaging device 31, the second imaging device 32, and the third imaging device 33 are the same. The relative positions of the first light source 21 and the first imaging device 31, the second light source 22 and the second imaging device 32, and the third light source 23 and the third imaging device 33 are all the same. The positions of the light sources, imaging devices, and gratings are fixed. The light source is located on one side of the imaging device and is tilted to emit light towards the battery cell 10 under test, which avoids the light source blocking the imaging device. The battery cell 10 emits light under illumination, and the emitted light is captured by the imaging device to form a grayscale image.

[0069] The first imaging device 31 is positioned opposite the first grating 41, meaning the first imaging device 31 is located in the normal direction of the first grating 41. The driving device 60 transports the battery cell 10 to be tested to the side of the first grating 41 away from the first imaging device 31, so that both the first grating 41 and the first imaging device 31 are located in the normal direction of the battery cell 10. When the first grating 41 blocks part of the light emitted by the first light source 21, the first imaging device 31 acquires a first image of the first grayscale value of the battery cell 10. The second imaging device 32 is positioned opposite the second grating 42, meaning the second imaging device 32 is located in the normal direction of the second grating 42. The driving device 60 transports the battery cell 10 to the side of the second grating 42 away from the second imaging device 32, so that both the second grating 42 and the second imaging device 32 are located in the normal direction of the battery cell 10. When the second grating 42 blocks part of the light emitted by the second light source 22, the second imaging device 32 acquires a second image of the first grayscale value of the battery cell 10. The driving device 60 transports the battery cell 10 under test to the side directly opposite the second imaging device 32, so that the third imaging device 33 is located in the normal direction of the battery cell 10 under test. When the light emitted by the third light source 23 is unobstructed, the third imaging device 33 acquires a second grayscale image of the battery cell 10 under test. The control module 50 can superimpose the first grayscale image and the second grayscale image according to their corresponding pixels to form a composite image; then, the control module 50 calculates the resistance of the battery cell under test by combining the composite image and the grayscale values ​​of the unobstructed second grayscale image.

[0070] This embodiment of the invention uses a conveyor belt to move the battery cell under test. Compared to the movement time of a grating, this method is shorter, reducing the time required for grating movement and increasing production capacity per unit time. It also reduces positional errors caused by the servo motor driving the grating, thus minimizing the impact on the accuracy of the composite image. While meeting the grating pattern design requirements, it eliminates the need for a servo motor to drive the grating, avoiding the composite image error caused by the servo motor's positioning accuracy. Specifically, it prevents the illumination areas of the first image and the second image with the first grayscale value from being incompletely complementary, thus failing to cover the entire battery cell under test. This embodiment only requires the battery cell under test to move along the conveyor belt to the designated position, improving the accuracy of the composite image, significantly increasing the testing speed, and saving on servo motor costs.

[0071] Based on the above embodiments, optionally, refer to Figure 1 The grating 40 includes a first grating 41 and a second grating 42, the patterns of the first grating 41 and the second grating 42 being complementary patterns. The driving device is used to drive the first grating 41 to move between the imaging device 30 and the battery cell 10 under test. When the first grating 41 blocks part of the light emitted by the light source 20, the imaging device 30 is used to acquire a first image of the first grayscale value of the battery cell 10 under test.

[0072] The driving device is used to drive the second grating 42 to move between the imaging device 30 and the battery cell 10 under test. When the second grating 42 blocks part of the light emitted by the light source 20, the imaging device 30 is used to acquire the first gray value of the second image of the battery cell 10 under test.

[0073] The driving device drives the first grating 41 and the second grating 42 to move between the imaging device 30 and the battery cell 10 under test, so that the first grating 41 and the second grating 42 are not obstructed. When the light emitted by the light source 20 is not obstructed, the imaging device 30 is used to acquire the second grayscale image of the battery cell 10 under test.

[0074] Among them, the drive unit is Figure 1 Not shown, the driving device can be a servo motor or a stepper motor, and the driving device drives the first grating 41 and the second grating 42 to move along a first direction. Figure 1 In this configuration, there is one control module 50, one light source, one imaging device, and two gratings. The positions of the light source 20, the imaging device 30, and the battery cell 10 under test are fixed. The grating 40 is a moving grating. The light source 20 is located on one side of the imaging device 30. The light source 20 is tilted to emit light towards the battery cell 10 under test, which can prevent the light source 20 from blocking the imaging device 30. The battery cell 10 under test emits light under the illumination of the light, and the emitted light is captured by the imaging device 30 to form a grayscale image.

[0075] refer to Figure 1In the left-hand diagram, the driving device controls the first grating 41 to move between the imaging device 30 and the battery cell 10 under test, so that both the imaging device 30 and the first grating 41 are located in the normal direction of the battery cell 10 under test. The first grating 41 can block part of the light emitted by the light source 20, and the imaging device 30 can acquire the first grayscale value of the battery cell 10 under the light source partially blocked by the first grating 41, forming a first image. (Reference) Figure 1 In the intermediate image, the driving device controls the second grating 42 to move between the imaging device and the battery cell 10 under test, so that both the imaging device 30 and the second grating 42 are located in the normal direction of the battery cell 10 under test. The second grating 42 can block part of the light emitted by the light source 20, and the imaging device 30 can acquire a second image of the first grayscale value of the battery cell 10 under the light source blocked by the second grating 42. (Reference) Figure 1 In the right-hand diagram, the driving device controls the first grating 41 and the second grating 42 to move between the imaging device 30 and the battery cell 10 under test, ensuring that the first grating 41 and the second grating 42 are not obstructed. With the light emitted from the light source 20 unobstructed, the imaging device 30 acquires a second grayscale image of the battery cell 10 under test. The control module 50 can superimpose the first grayscale image and the second grayscale image according to their corresponding pixels to form a composite image; then, the control module 50 calculates the resistance of the battery cell under test by combining the composite image and the grayscale values ​​of the unobstructed second grayscale image.

[0076] This invention utilizes a first and second grating with complementary patterns for testing, applicable to contactless testing of solar cells. The system employs the first and second gratings as moving gratings, which can be arbitrarily designed according to the grating pattern requirements of the cell under test (10). This solves the problem of inaccurate matching of movement precision to the cell under test when using a single grating. It is suitable for resistance testing of cells with complex metallized patterns, such as those without a main grid (OBB) or those with a main grid around the outer ring. Using a first and second grating with complementary patterns avoids the accuracy error problem caused by a single grating moving with a servo motor; it also improves the accuracy of test results. Furthermore, due to the complementary grating design, the movement direction and mode of the grating 40 can be switched according to test requirements, improving compatibility with the entire test line.

[0077] Based on the above embodiments, optionally, refer to Figure 1 The driving device is used to drive the first grating 41 and the second grating 42 to move along the first direction, or, Figure 5 This is a schematic diagram of another resistance testing system provided in this embodiment of the present invention, for reference. Figure 5The driving device is used to drive the first grating 41 and the second grating 42 to move along the second direction; wherein the first direction and the second direction are perpendicular to each other.

[0078] in, Figure 5 and Figure 1 The only difference is the direction of the grating driven by the drive unit; other settings are the same. Figure 1 They are all the same and have the same beneficial effects. Figure 1 The driving device in the middle is used to drive the first grating 41 and the second grating 42 to move along the first direction. Figure 5 The driving device is used to drive the first grating 41 and the second grating 42 to move along a second direction. For example, the first direction can be perpendicular to the second direction. The first direction can be the width direction of the battery cell 10 under test, and the second direction can be the length direction of the battery cell 10 under test. This minimizes the moving distance of the grating 40, reduces the time required for the grating 40 to move, and increases the production capacity per unit time. Alternatively, the first direction can intersect with the second direction. The first and second directions can be along the diagonal direction of the battery cell under test, or any tilted direction.

[0079] Based on the above embodiments, optionally, Figure 6 This is a schematic diagram of another resistance testing system provided in this embodiment of the present invention, for reference. Figure 6 The resistance testing system also includes: a rotating device 70, on which at least two gratings 40 are located; and a driving device for driving the at least two gratings 40 to move via the rotating device 70.

[0080] At least two gratings can also be moved by rotation, including clockwise or counterclockwise rotation, which facilitates the driving device to drive the at least two gratings 40 to move through the rotating device 70.

[0081] Based on the above embodiments, optionally, refer to Figure 6 The grating 40 includes a first grating 41, a second grating 42, and a third grating 43. The patterns of the first grating 41, the second grating 42, and the third grating 43 are complementary patterns.

[0082] The driving device is used to drive the first grating 41 to move between the imaging device 30 and the battery cell 10 under test through the rotating device 70. When the first grating 41 blocks part of the light emitted by the light source 20, the imaging device 30 is used to acquire the first gray value first image of the battery cell 10 under test.

[0083] The driving device is used to drive the second grating 42 to move between the imaging device 30 and the battery cell 10 under test via the rotating device 70. When the second grating 42 blocks part of the light emitted by the light source 20, the imaging device 30 is used to acquire a second image of the first gray value of the battery cell 10 under test.

[0084] The driving device is used to drive the third grating 43 to move between the imaging device 30 and the battery cell 10 under test through the rotating device 70. When the third grating 43 blocks part of the light emitted by the light source 20, the imaging device 30 is used to acquire the first gray value third image of the battery cell 10 under test.

[0085] The driving device drives the first grating 41, the second grating 42, and the third grating 43 to move between the imaging device 30 and the battery cell 0 under test without the first grating 41, the second grating 42, and the third grating 43 obstructing the light emitted by the light source 20. When the light emitted by the light source 20 is not obstructed, the imaging device 30 is used to acquire the second grayscale image of the battery cell under test.

[0086] Among them, the drive unit is Figure 1 Not shown in the image. Figure 6 In this configuration, there is one control module 50, one light source, one imaging device, and two gratings. The positions of the light source 20, the imaging device 30, and the battery cell 10 under test are fixed. The grating 40 is a moving grating. The light source 20 is located to one side of the imaging device 30 and is tilted to emit light towards the battery cell 10 under test, which avoids the light source 20 blocking the imaging device 30. The battery cell 10 emits light under the illumination of the light, and the emitted light is captured by the imaging device 30 to form a grayscale image. The drive device controls the rotation device 70 to move the grating 40 in a clockwise direction.

[0087] refer to Figure 6 In the first figure, the driving device controls the rotating device 70 to rotate the first grating 41 between the imaging device 30 and the battery cell 10 under test, so that the imaging device 30 and the first grating 41 are both located in the normal direction of the battery cell 10 under test. The first grating 41 can block part of the light emitted by the light source 20, and the imaging device 30 can acquire the first gray value of the battery cell 10 under the light source blocked by the first grating 41.

[0088] refer to Figure 6 In the second figure, the driving device controls the rotating device 70 to move the second grating 42 between the imaging device 30 and the battery cell 10 under test, so that both the imaging device 30 and the second grating 42 are located in the normal direction of the battery cell 10 under test. The second grating 42 can block part of the light emitted by the light source, and the imaging device 30 can acquire the first gray value of the second image of the battery cell 10 under the light source blocked by the second grating 42.

[0089] refer to Figure 6 In the third figure, the driving device controls the rotating device 70 to move the third grating 43 between the imaging device 30 and the battery cell 10 under test, so that both the imaging device 30 and the third grating 43 are located in the normal direction of the battery cell 10 under test. The third grating 43 can block part of the light emitted by the light source 20, and the imaging device 30 can acquire the first gray value third image of the battery cell 10 under the light source 20 blocked by the third grating 43.

[0090] refer to Figure 6 In the last diagram, a portion of the rotating device 70 is not obstructed by the gratings. The control device drives the rotating device 70 to move the first grating 41, the second grating 42, and the third grating 43 to a position between the imaging device 30 and the battery cell 10 under test, where the first grating 41, the second grating 42, and the third grating 43 are no longer obstructed. With the light emitted from the light source 20 unobstructed, the imaging device 30 acquires a second grayscale image of the battery cell 10 under test. The control module 50 can superimpose the first grayscale image, the second grayscale image, and the third grayscale image according to their corresponding pixels to form a composite image. Then, the control module 50 calculates the resistance of the battery cell under test by combining the composite image and the grayscale values ​​of the unobstructed second grayscale image.

[0091] Based on the above embodiments, optionally, the light source includes a laser light source; the resistance testing system further includes a laser homogenization device, which is used to homogenize the light emitted by the laser light source.

[0092] The laser homogenizer can be located downstream of the laser source in the optical path, or it can be placed adjacent to the laser source; the specific location can be set according to requirements. The function of the laser homogenizer is to homogenize the intensity distribution of the laser source to meet the laser beam quality requirements of various applications.

[0093] Based on the above embodiments, optionally, the imaging device is a camera; the camera includes a grayscale camera or a charge-coupled device camera.

[0094] The imaging device is a camera; the camera includes a grayscale camera or a charge-coupled device camera. The imaging device is used to acquire grayscale images of the light source under different occlusion conditions, so as to facilitate the subsequent resistance calculation of the battery cell under test.

[0095] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0096] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A resistance testing system, characterized in that, include: A light source, used to emit light onto the battery cell under test; An imaging device and a grating are provided, the grating being located between the imaging device and the battery cell under test; the grating is used to block part of the light emitted by the light source; the grating includes at least two gratings, the patterns of the at least two gratings being complementary; when the at least two gratings block part of the light emitted by the light source, the imaging device is used to acquire at least two first grayscale images of the battery cell under test; when the light emitted by the light source is not blocked, the imaging device is also used to acquire a second grayscale image of the battery cell under test. A control module is electrically connected to the imaging device and the light source, with the light source located on one side of the imaging device.

2. The resistance testing system according to claim 1, characterized in that, The at least two first grayscale value images are complementary; The resistance testing system also includes: a driving device; With the positions of the light source and the battery cell under test fixed, the driving device is electrically connected to the control module and connected to the at least two gratings, and the driving device is used to drive the at least two gratings to move; or, with the positions of the light source and the gratings fixed, the driving device is connected to the battery cell under test, and the driving device is used to drive the battery cell under test to move.

3. The resistance testing system according to claim 2, characterized in that, The driving device includes a grating driving device and a battery cell driving device; The grating driving device includes a servo motor or a stepper motor; The battery cell drive device includes a conveyor belt.

4. The resistance testing system according to claim 2, characterized in that, The imaging device includes a first imaging device, a second imaging device, and a third imaging device; the light source includes a first light source, a second light source, and a third light source; the grating includes a first grating and a second grating, wherein the patterns of the first grating and the second grating are complementary patterns. The control module is electrically connected to the first imaging device, the second imaging device, the third imaging device, the first light source, the second light source, and the third light source. The first light source is located on one side of the first imaging device, and the first imaging device is directly opposite the first grating. The second light source is located on one side of the second imaging device, and the second imaging device is directly opposite the second grating. The third light source is located on one side of the third imaging device, and the position directly opposite the third imaging device is not obstructed by the first grating or the second grating. The driving device is used to drive the battery cell under test to move to the side of the first grating away from the first imaging device. When the first grating blocks part of the light emitted by the first light source, the first imaging device is used to acquire the first gray value first image of the battery cell under test. The driving device is used to drive the battery cell under test to move to the side of the second grating away from the second imaging device. When the second grating blocks part of the light emitted by the second light source, the second imaging device is used to acquire the first grayscale value of the battery cell under test. The driving device is used to drive the battery cell under test to move to the side facing the third imaging device. When the light emitted by the third light source is not blocked, the third imaging device is used to acquire a second grayscale image of the battery cell under test.

5. The resistance testing system according to claim 2, characterized in that, The grating includes a first grating and a second grating, wherein the patterns of the first grating and the second grating are complementary patterns; The driving device is used to drive the first grating to move between the imaging device and the battery cell under test. When the first grating blocks part of the light emitted by the light source, the imaging device is used to acquire the first grayscale value of the battery cell under test. The driving device is used to drive the second grating to move between the imaging device and the battery cell under test. When the second grating blocks part of the light emitted by the light source, the imaging device is used to acquire a second image of the first grayscale value of the battery cell under test. The driving device drives the first grating and the second grating to move between the imaging device and the battery cell under test without the first grating and the second grating obstructing them. When the light emitted by the light source is not obstructed, the imaging device is used to acquire a second grayscale image of the battery cell under test.

6. The resistance testing system according to claim 5, characterized in that, The driving device is used to drive the first grating and the second grating to move along a first direction, or the driving device is used to drive the first grating and the second grating to move along a second direction; The first direction and the second direction intersect each other.

7. The resistance testing system according to claim 5, characterized in that, Also includes: A rotating device, wherein the at least two gratings are located on the rotating device; The driving device is used to drive the at least two gratings to move via the rotating device.

8. The resistance testing system according to claim 7, characterized in that, The grating includes a first grating, a second grating, and a third grating, wherein the patterns of the first grating, the second grating, and the third grating are complementary patterns. The driving device is used to drive the first grating to move between the imaging device and the battery cell under test through the rotating device. When the first grating blocks part of the light emitted by the light source, the imaging device is used to acquire the first grayscale value of the battery cell under test. The driving device is used to drive the second grating to move between the imaging device and the battery cell under test through the rotating device. When the second grating blocks part of the light emitted by the light source, the imaging device is used to acquire a second image of the first grayscale value of the battery cell under test. The driving device is used to drive the third grating to move between the imaging device and the battery cell under test through the rotating device. When the third grating blocks part of the light emitted by the light source, the imaging device is used to acquire a third image of the first grayscale value of the battery cell under test. The driving device drives the first grating, the second grating, and the third grating to move between the imaging device and the battery cell under test without the first grating, the second grating, and the third grating obstructing the light emitted by the light source. When the light emitted by the light source is not obstructed, the imaging device is used to acquire a second grayscale image of the battery cell under test.

9. The resistance testing system according to claim 1, characterized in that, The light source includes a laser light source; The resistance testing system further includes a laser homogenization device, which is used to homogenize the light emitted by the laser source.

10. The resistance testing system according to claim 1, characterized in that, The imaging device is a camera; the camera includes a grayscale camera or a charge-coupled device (CCD) camera.

Images