Method and device for automatically testing mechanical properties of single particles of lithium battery material

Abstract

This application provides an automated testing method and apparatus for the mechanical properties of single-particle lithium battery materials, relating to the field of automatic control technology. The method includes: starting with user-inputted particle testing requirements, an automated global particle screening process is completed using a visual recognition module. After confirming that the number of qualified particles meets preset requirements, the physical coordinates of all particles to be tested are accurately located, forming a set of particle coordinates. Based on this coordinate set, the system plans the optimal path for the indenter to move, driving the indenter of the pressure testing module to precisely align itself above each target particle sequentially. Subsequently, an automatic focusing module determines the height of the particle's apex, and the indenter presses vertically downwards until the particle breaks, simultaneously recording core mechanical data such as the crushing force, crushing displacement, and load-displacement curve. This method achieves full automation from particle screening and positioning to testing, significantly improving testing efficiency and data accuracy, and meeting the rapid testing needs of massive samples.

Description

Technical Field

[0001] This application relates to the field of automatic control technology, and in particular to an automatic testing method and apparatus for the mechanical properties of single particles of lithium battery materials. Background Technology

[0002] In materials science fields such as lithium-ion battery cathode materials, ceramic microspheres, and pharmaceutical powders, the single-particle mechanical properties of powder materials (such as crushing strength, Young's modulus, and deformation characteristics) are key indicators for evaluating material processing performance and final product quality. For example, in the lithium battery rolling process, the compressive strength of the particles directly determines the compaction density of the electrode and the cycle life of the battery. Therefore, using single-particle mechanical property testing equipment to conduct precise compression tests on micron-sized particles has become an indispensable part of materials research and development and quality control.

[0003] Currently, the mechanical property testing of single particles mainly relies on semi-automated micro-compressors or nanoindenters. The typical operating procedure is as follows: the operator first disperses the powder to be tested on a support platform, visually inspects it under a microscope to locate well-dispersed, regularly shaped particles; then, the operator manually controls the displacement platform to move the target particle directly under the indenter, manually adjusts the focus to confirm the contact point, and finally controls the indenter to press down until the particle breaks. After completing one test, the operator needs to use the microscope again to locate the next particle and repeat the above alignment and testing steps.

[0004] However, the aforementioned existing technologies have obvious drawbacks: the entire testing process relies heavily on manual particle screening and alignment, resulting in extremely low overall testing efficiency. Furthermore, the subjectivity and operational errors of manual sample selection make it difficult to guarantee the accuracy and consistency of test data, making it difficult to meet the needs of rapid and accurate statistics for massive samples. Summary of the Invention

[0005] This application provides an automatic testing method and apparatus for the mechanical properties of single particles of lithium battery materials, which improves the accuracy, continuity and overall efficiency of automatic testing of the mechanical properties of single particles.

[0006] In a first aspect, this application provides an automatic testing method for the mechanical properties of single-particle lithium battery materials, applied to a single-particle mechanical property testing device. The device includes a vision recognition module, an automatic focusing module, and a pressure testing module. The pressure testing module includes an indenter. The method includes: based on user-inputted test particle requirements, determining whether all particles meet preset test requirements using the vision recognition module; if the test requirements are met, determining the coordinate set of the particles to be tested; planning a target movement path based on the coordinate set of the particles to be tested; controlling the pressure testing module to move sequentially above each particle to be tested according to the target movement path; for each target particle to be tested, focusing and positioning using the automatic focusing module to determine the height of the target particle's apex; based on the height of the target particle's apex, controlling the indenter to press down until the particle breaks, and recording mechanical property data, which includes at least the crushing force value, crush displacement, and load-displacement curve.

[0007] By adopting the above technical solution, relying on the collaborative cooperation of the visual recognition module, the automatic focusing module, and the pressure testing module, the system first completes the automated screening of all particles based on the user's testing requirements, replacing manual visual sampling and avoiding sampling deviations caused by human subjectivity from the source. Then, the system achieves automated movement of the indenter through path planning, and with the help of the automatic focusing module, it accurately locates the height of the particle apex, allowing the indenter's pressing action to be executed based on precise height data. No manual intervention is required for alignment, focusing, or other operations throughout the process. Each module completes the test and records multi-dimensional mechanical data according to the preset logic, which not only greatly improves the overall efficiency of single-particle mechanical performance testing, but also ensures the accuracy and consistency of test data, meeting the needs of rapid and accurate statistical analysis of massive samples.

[0008] In conjunction with some embodiments of the first aspect, in some embodiments, the step of determining whether the global particles meet the preset test requirements through the visual recognition module specifically includes: obtaining the test particle requirements, which at least include particle size; controlling the visual recognition module to perform a panoramic scan of the sample area on the support platform to obtain a global particle distribution image; identifying the contours of each particle in the global particle distribution image through a watershed algorithm; calculating the physical parameters of each particle, which at least include particle size; based on the physical parameters, selecting multiple target particles that meet the user requirements according to the test particle requirements; performing a secondary quality judgment on each target particle to obtain the number of qualified particles; if the number of qualified particles is greater than a preset threshold for the number of qualified particles, then it is determined that the global particles meet the test requirements.

[0009] By adopting the above technical solution, the core test particle requirements, including particle size, are first clearly defined, providing a clear and quantifiable standard for visual recognition screening. Then, a panoramic scan is used to obtain a global particle distribution image, achieving full coverage of particles in the sample area of ​​the test platform and avoiding local omissions in manual screening. Combined with the watershed algorithm, the particle outline is accurately identified, providing a basis for the accurate calculation of physical parameters such as particle size. The first round of screening is then completed based on the parameters. Finally, a second quality judgment is added, and a threshold for the number of qualified particles is set. This progressive screening logic ensures that all screened particles meet the user's preset requirements and that there is a sufficient number of effective test samples in the global particle count. This lays a reliable sample foundation for subsequent batch automated testing and enhances the statistical significance of the test results.

[0010] In conjunction with some embodiments of the first aspect, in some embodiments, the step of performing a secondary quality determination on each target particle specifically includes: obtaining the quality parameters in the physical parameters, the quality parameters including at least solidity and aspect ratio; determining the number of non-irregular particles in the target particles based on the quality parameters and a preset threshold for irregularly shaped particles; determining particles with no other particles within a set radius around each non-irregularly shaped particle as qualified particles; and counting the number of qualified particles.

[0011] By adopting the above technical solution, solidity and aspect ratio are selected as core quality parameters. These two parameters can intuitively reflect the morphological regularity and structural integrity of the particles, which are key indicators to ensure the accuracy of mechanical performance testing. Based on the determination of thresholds for irregularly shaped particles, non-irregularly shaped particles are screened out, thus avoiding test errors caused by particle irregularities in terms of morphology. Then, by setting a radius range, qualified particles without other particles around them are screened out to avoid interference from adjacent particles on the pressing action of the indenter during the test. The double screening constitutes the core logic of the secondary quality judgment, ensuring that the finally screened qualified particles all meet the test conditions of morphological regularity and independent dispersion. This eliminates the test deviation caused by the state of the particles themselves at the individual sample level, further improving the accuracy of the test data.

[0012] In conjunction with some embodiments of the first aspect, in some embodiments, the pressure testing module further includes an XYZ three-axis moving mechanism. The step of determining the set of coordinates of the particles to be tested specifically includes: constructing an XYZ three-dimensional motion coordinate system; obtaining multiple pixel center coordinates of each qualified particle in the global particle distribution image; converting each pixel center coordinate into the physical position coordinates of each qualified particle in the XYZ three-dimensional motion coordinate system based on preset visual calibration parameters; and summing up all the physical position coordinates to obtain the set of coordinates of the particles to be tested.

[0013] By adopting the above technical solution, an XYZ three-dimensional motion coordinate system is first constructed to provide a unified spatial positioning reference for the movement of the indenter. Then, the pixel center coordinates of the qualified particles are extracted, and the pixel coordinates are accurately converted to physical position coordinates based on preset visual calibration parameters. Finally, the coordinates of the particles to be tested are summarized. The construction of the XYZ three-dimensional motion coordinate system establishes a spatial correspondence between the movement of the indenter and the positioning of the particles, eliminating positioning deviations caused by inconsistencies in the coordinate system. The accurate conversion of the visual calibration parameters achieves a deviation-free mapping from image pixel coordinates to actual physical coordinates, making the physical position coordinates of each qualified particle more accurate. This provides reliable coordinate data support for the subsequent planning and precise alignment of the indenter's movement path, ensuring that the indenter can move accurately above the target particles.

[0014] In conjunction with some embodiments of the first aspect, in some embodiments, the step of planning the target movement path based on the set of coordinates of the particles to be tested specifically includes: obtaining the current position coordinates of the pressure head of the pressure testing module; mapping the current position coordinates to the XY plane coordinate system where the bearing platform is located to obtain the plane coordinates of the pressure head; using the plane coordinates of the pressure head as the starting point, using the shortest path planning algorithm to calculate the optimal movement order for traversing all coordinate points in the set of coordinates of the particles to be tested, and generating the target movement path.

[0015] By adopting the above technical solution, the current coordinates of the pressure head are mapped to the plane of the support platform, realizing the unification of the planar coordinates of the pressure head position and the particle coordinates, providing a consistent calculation benchmark for path planning. The application of the shortest path planning algorithm can calculate the optimal order of pressure head movement under the premise of traversing all particles to be tested, minimizing the invalid movement distance of the pressure head in the XY plane, making the movement of the pressure head more planned, effectively improving the overall efficiency of the pressure head aligning with each particle to be tested in sequence, and reducing the time loss during the testing process.

[0016] In conjunction with some embodiments of the first aspect, in some embodiments, the step of controlling the pressure testing module to move sequentially above each particle to be tested according to the target movement path specifically includes: sequentially extracting the target plane coordinates of each target particle to be tested in the target movement path; controlling the XYZ three-axis moving mechanism to drive the pressure head to rise along the Z-axis direction to a preset safe height; controlling the XYZ three-axis moving mechanism to drive the pressure head to move in the XY plane until the center of the pressure head coincides with the target plane coordinates.

[0017] By adopting the above technical solution, the safety height in the Z-axis direction is increased, which effectively avoids the risk of collision with the support platform and particles during the movement of the indenter in the XY plane, protecting the indenter and the particles under test from damage. Furthermore, the alignment standard in the XY plane is based on the coincidence of the center of the indenter with the target plane coordinates, which achieves precise center alignment between the indenter and the target particle. This ensures that the subsequent indenter presses down perpendicularly to the apex of the particle, avoiding deviations in the test force value caused by alignment misalignment. This makes the force application in the compression test more accurate and improves the accuracy of mechanical performance data acquisition.

[0018] In conjunction with some embodiments of the first aspect, in some embodiments, the single-particle mechanical property testing device further includes a self-cleaning module, which includes an alcohol storage bottle, a titration pump, an alcohol titration head, and a filter paper clamping block. The method further includes: after recording the mechanical property data, controlling the pressure head to move above the filter paper of the self-cleaning module; controlling the titration pump to add alcohol from the alcohol storage bottle to the filter paper via the alcohol titration head; controlling the pressure head to press down until it contacts the filter paper; and controlling the filter paper clamping block to reciprocate to remove residues from the end of the pressure head through relative friction between the filter paper and the pressure head.

[0019] By adopting the above technical solution, after recording the mechanical data, the pressure head is first moved above the filter paper of the self-cleaning module. Then, alcohol is added to the filter paper via a titration pump. After the pressure head contacts the filter paper, the reciprocating movement of the filter paper clamping block creates relative friction between the filter paper and the end of the pressure head, removing residues. The addition of alcohol dissolves and wets the particle residues at the end of the pressure head, reducing the adhesion between the residues and the pressure head. The relative friction caused by the reciprocating movement of the filter paper clamping block completely removes the dissolved residues through physical action. This self-cleaning process is completed automatically after each test, replacing the tedious manual cleaning operation. It ensures the cleanliness of the pressure head end, preventing the residue of the previous particle from affecting the testing accuracy of the next particle, and does not interrupt the testing process, further improving the continuity and efficiency of the overall test.

[0020] In a second aspect, this application provides a single-particle mechanical property testing device, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, and the memory is used to store computer program code, which includes computer instructions, and the one or more processors call the computer instructions to cause the single-particle mechanical property testing device to perform the method described in the first aspect and any possible implementation thereof.

[0021] Thirdly, this application provides a computer-readable storage medium including instructions that, when executed on a single-particle mechanical property testing device, cause the single-particle mechanical property testing device to perform the method described in the first aspect and any possible implementation thereof.

[0022] Fourthly, this application provides a computer program product, including a computer program that, when run on a single-particle mechanical property testing device, causes the single-particle mechanical property testing device to perform the method described in the first aspect and any possible implementation thereof.

[0023] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0024] 1. By employing a collaborative approach involving visual recognition, autofocus, and stress testing modules, combined with user testing requirements, the technology achieves automated global particle screening, coordinate positioning, path planning, and standardized compression testing and data recording. This effectively solves the technical problems of existing technologies where the entire testing process is highly dependent on manual labor, resulting in extremely low efficiency. Furthermore, the subjectivity and operational errors in manual sample selection lead to poor accuracy and consistency of test data, making it impossible to meet the needs of rapid and accurate statistical analysis of massive samples. Consequently, the technology achieves full automation of the testing process, significantly improved testing efficiency, more accurate and consistent test data collection, and can efficiently adapt to the needs of precise testing of massive samples.

[0025] 2. By employing a technical approach that uses solidity and aspect ratio as core quality parameters, combined with a threshold for judging irregularly shaped particles to screen for non-irregularly shaped particles, and verifies and selects qualified particles without interference from adjacent particles within a set radius range, this approach effectively solves the technical problems in existing technologies where manual sampling cannot accurately determine particle morphology suitability, is prone to selecting irregularly shaped particles, and causes test data distortion due to interference from adjacent particles. This achieves the technical effect of accurately removing irregularly shaped particles and effectively avoiding interference from adjacent particles, ensuring the validity of test samples from both morphological and spatial distribution dimensions, and improving the accuracy of subsequent compression testing operations.

[0026] 3. Due to the adoption of a self-cleaning module linkage, the technology of automatically removing residues from the end of the pressure head by applying alcohol to wet the head and rubbing the filter paper against the pressure head after each test effectively solves the technical problems in the existing technology where the residue of the previous particle at the end of the pressure head affects the test accuracy of the next particle, and manual cleaning is cumbersome and interrupts the test process. Thus, it realizes the automation of pressure head end cleaning, avoids residual samples interfering with test accuracy, and does not require interruption of the test process, thereby improving the overall test continuity and efficiency. Attached Figure Description

[0027] Figure 1This is a schematic diagram of the overall structure of the single-particle mechanical property testing device in the embodiments of this application;

[0028] Figure 2 This is a flowchart illustrating an automatic testing method for the mechanical properties of single lithium battery materials in an embodiment of this application.

[0029] Figure 3 This is a schematic diagram of the self-cleaning module structure in the single-particle mechanical property testing device in the embodiments of this application;

[0030] Figure 4 This is a schematic diagram of the physical structure of a single-particle mechanical property testing device in the embodiments of this application. Detailed Implementation

[0031] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0033] For ease of understanding, the single-particle mechanical property testing device provided in this embodiment is described below. Please refer to... Figure 1 , Figure 1 This is a schematic diagram of the overall structure of the single-particle mechanical property testing device in the embodiments of this application.

[0034] exist Figure 1 The single-particle mechanical property testing device includes a scanning platform, a vision recognition module, an autofocus module, and a pressure testing module; the pressure testing module includes an indenter.

[0035] The scanning platform is located in the middle of the device and is equipped with a light-transmitting observation window (such as a glass plate) to hold the particle sample to be tested. It can move with high precision in the horizontal plane (XY axis).

[0036] The visual recognition module can be set below the scanning platform, in the form of an inverted microscope. Its light path passes through the light-transmitting observation window of the scanning platform to perform a panoramic scan of the sample area from bottom to top, identify the particle outline and calculate physical parameters (such as particle size and shape), so as to realize the automated screening of the particles to be tested.

[0037] The autofocus module is linked to the optical system of the vision recognition module (shown as knob position) to control the raising and lowering of the objective lens focal plane and to identify the optimal image clarity for the target particles.

[0038] The pressure testing module is positioned directly above the scanning platform and includes a high-precision indenter and a Z-axis drive mechanism. This module drives the indenter to press vertically downwards, applying pressure to the target particles below to complete the compression test and acquire mechanical property data.

[0039] The visual recognition module, autofocus module, and pressure testing module are interconnected, and can automatically trigger the collaborative work of each module according to the testing process. The pressure testing module's indenter is connected to the XYZ three-axis moving mechanism to achieve precise movement and positioning of the indenter in three-dimensional space, ensuring that the indenter can be aligned with each particle to be tested in sequence to complete the test.

[0040] The method provided in this embodiment will be described in detail below with reference to the above-described device structure. Please refer to [link / reference]. Figure 1 This is a flowchart illustrating an automatic testing method for the mechanical properties of single particles of lithium battery materials in this application.

[0041] S101. Based on the test particle requirements input by the user, the visual recognition module determines whether the global particles meet the preset test requirements.

[0042] The visual recognition module is the core functional module in the testing device used to acquire particle images, identify particle outlines and physical parameters. It is a key component for the device to achieve automated particle screening. It is used to capture and analyze the particle distribution information on the support platform. For example, this module can use a high-definition industrial camera with an image acquisition card to achieve image acquisition and real-time analysis of the sample area on the support platform. The global particles refer to all lithium battery material single particles that are dispersed on the support platform and are within the visual recognition range of the testing device. It refers to the entire set of particles that may be screened as test objects in this test.

[0043] This step is executed at the initial stage of the automatic testing of the mechanical properties of single particles of lithium battery materials. The scenario is that the user has completed the dispersion of the powder sample to be tested on the support platform and input the specific test particle requirements into the testing device. This is the first core step in the automatic testing process, used to determine whether the overall particle count on the support platform meets the testing conditions, avoiding subsequent invalid testing operations. During execution, the device first receives the test particle requirements input by the user through the operating interface (such as particle size range, implicit requirements related to particle morphology, etc.), then activates the vision recognition module, controlling this module to perform a comprehensive, no-dead-angle image acquisition (i.e., panoramic scan) of the entire sample area on the support platform, capturing the distribution image of the entire particle count.

[0044] Next, the visual recognition module preprocesses the acquired global particle distribution image, and then uses an image recognition algorithm (such as the watershed algorithm mentioned later) to identify the outline of each particle in the image, and then calculates the physical parameters of each particle (including at least the particle size); after that, the device compares the physical parameters of each particle with the test particle requirements input by the user, and selects multiple target particles that initially meet the user's requirements.

[0045] Then, a second quality assessment is performed on these target particles: During the assessment process, the testing device first extracts the corresponding quality parameters from the physical parameters of each target particle calculated by S101, focusing on extracting the two core indicators of solidity and aspect ratio. Simultaneously, the extracted quality parameters are verified, and abnormal data (such as invalid data with solidity > 1 or aspect ratio < 1) is removed to ensure the accuracy of the quality parameters. Subsequently, the testing device calls a preset threshold for irregularly shaped particles, comparing the quality parameters (solidity and aspect ratio) of each target particle with the corresponding threshold one by one. It determines whether the solidity of each target particle is not lower than the preset solidity threshold and whether the aspect ratio is not higher than the preset aspect ratio threshold. If both conditions are met, the target particle is determined to be a non-irregularly shaped particle; if either condition is not met, it is determined to be an irregularly shaped particle. The number of all non-irregularly shaped particles is then counted to obtain the total number of non-irregularly shaped particles. Afterwards, the measurement... The testing device calculates the particle distribution within a set radius around each non-irregularly shaped particle based on the global particle distribution image acquired by the visual recognition module and the pixel coordinates of each non-irregularly shaped particle. By converting the image pixel distance to the actual physical distance (relying on the visual calibration parameters mentioned in S102), it determines whether there are other particles (including target particles and global particles not selected as target particles) within the set radius around each non-irregularly shaped particle. If there are no other particles within the set radius around a non-irregularly shaped particle, the non-irregularly shaped particle is determined to be a qualified particle. If other particles exist, the non-irregularly shaped particle is determined to be unqualified and removed from the qualified particle screening range. Finally, the testing device counts all particles determined to be qualified particles, obtains the number of qualified particles, and sends the number to the testing device control unit for subsequent comparison with the preset qualified number threshold, completing the overall determination of global particles in S101.

[0046] The device counts the specific number of qualified particles. Finally, it compares the number of qualified particles with a preset threshold. If the number of qualified particles is greater than the threshold, it determines that the total number of particles meets the preset test requirements and can proceed to the next test step. If it does not meet the requirements, it issues a prompt signal (such as an audible and visual alarm) to remind the user to redistribute the sample or adjust the test requirements.

[0047] The core effect of this step is to replace the manual particle selection process in existing technologies. By using a visual recognition module for automated identification and selection, the subjective errors of manual sampling are avoided. At the same time, the test suitability of all particles is determined in advance, avoiding invalid tests due to insufficient particle quantity or poor particle quality. This improves the efficiency of the early stage of testing and lays the foundation for the automation and accuracy of the entire testing process. It also solves the problems of cumbersome, inefficient, and error-prone preparation in the early stage of testing in existing technologies.

[0048] S102. If the test requirements are met, then determine the set of coordinates of the particles to be tested;

[0049] If the overall particle count meets the preset test requirements, it indicates that the testing device has confirmed that there are a sufficient number of qualified particles on the platform, and can officially enter the spatial positioning stage of the particles to be tested, providing precise positional support for the subsequent movement of the pressure head above each qualified particle.

[0050] The process of locating the coordinates of the particles under test is initiated as follows: First, a unified XYZ three-dimensional motion coordinate system is constructed. This coordinate system matches the displacement platform and indenter movement trajectory of the testing device. A fixed reference point on the support platform is used as the origin, with the X and Y axes parallel to the platform plane and the Z axis perpendicular to it. This coordinate system is used to uniformly describe the spatial position of the indenter and the particles under test. Next, the visual recognition module extracts the pixel center coordinates of all compliant particles in the global particle distribution image. These pixel center coordinates are two-dimensional coordinates, representing only the position of the compliant particles within the image plane and not their actual spatial position. Then, the testing device calls preset visual calibration parameters, which are determined in advance through calibration experiments, to establish the image pixel coordinates. The precise mapping between the actual physical location coordinates eliminates positioning errors caused by factors such as image distortion and camera installation deviation. Based on this visual calibration parameter, the testing device converts the two-dimensional pixel center coordinates of each qualified particle into the corresponding three-dimensional physical location coordinates in the XYZ three-dimensional motion coordinate system. These three-dimensional physical location coordinates can accurately represent the X and Y positions of the qualified particles on the bearing platform plane, as well as the initial height reference value of the particles in the Z-axis direction. Finally, the testing device summarizes and sorts the three-dimensional physical location coordinates of all qualified particles to form an ordered coordinate list. This coordinate list is the set of coordinates of the particles to be tested, and the coordinate set is stored in the control unit of the testing device for subsequent path planning steps in S103.

[0051] The core effect of this step is to achieve precise spatial positioning of the qualified particles, providing reliable positional data support for the subsequent automated movement and precise alignment of the indenter. This effectively solves the technical problems of large positioning errors, cumbersome operation, and low efficiency when manually controlling the displacement platform to position particles in existing technologies. By establishing a unified XYZ three-dimensional motion coordinate system and a precise coordinate transformation mechanism, the accuracy of the coordinates of each particle under test is ensured, avoiding indenter alignment errors caused by coordinate deviations. This further improves the accuracy of the testing process and promotes the testing process towards full automation.

[0052] S103. Plan the target movement path based on the set of coordinates of the particles to be measured;

[0053] This step is performed when the testing device has obtained the precise spatial coordinates of all the particles to be tested. An optimal movement path needs to be planned to ensure that the pressure head can move efficiently and sequentially to the top of each particle to be tested, reducing unnecessary movement time and improving the overall testing efficiency.

[0054] During execution, the control unit of the testing device first obtains the current three-dimensional spatial coordinates of the pressure head from the position detection unit of the pressure testing module. If it is the initial stage of the test, the pressure head is usually in the preset initial safe position (i.e., the fixed safe height above the support platform). Subsequently, the testing device maps the current three-dimensional spatial coordinates of the pressure head to the XY plane coordinate system where the support platform is located to obtain the plane coordinates of the pressure head. That is, the height in the Z-axis direction is ignored, and only the plane position of the pressure head in the X and Y directions is retained. This is because when the pressure head moves above the particles, the Z-axis direction needs to be adjusted to the safe height separately. The core of path planning is to optimize the movement trajectory in the XY plane and reduce the movement distance.

[0055] Next, the testing device uses the plane coordinates of the indenter as the starting point of the path and calls the preset shortest path planning algorithm (a greedy algorithm, genetic algorithm, etc. can be flexibly selected according to the number of particles to be tested). The XY plane coordinates of all qualified particles in the set of particle coordinates to be tested are used as target points. The optimal movement order for traversing all target points is calculated. The core criterion for the optimal movement order is that the total movement distance of the indenter in the XY plane is the shortest and the movement time is the least, avoiding repeated back-and-forth movements. Finally, based on the calculated optimal movement order and the initial Z-axis height reference value of each qualified particle, the testing device generates a complete target movement path, determines the safe Z-axis height of the indenter when moving between each target point (ensuring that the indenter does not collide with the support platform or other particles during the movement), and sends the target movement path to the control unit of the pressure testing module for subsequent execution in S104.

[0056] The core effect of this step is to minimize the ineffective movement distance and time of the indenter during the movement process through optimal path planning, which greatly improves the efficiency of the indenter aligning with each particle to be tested sequentially. This effectively solves the technical problems of disordered paths, excessive back-and-forth movement, and low efficiency when the indenter is manually controlled to move. At the same time, the automated implementation of path planning completely replaces the manual operation of the displacement platform to plan the movement path, further promoting the full automation of the testing process and providing efficiency assurance for the rapid testing of massive amounts of single lithium battery materials.

[0057] S104. Control the pressure testing module to move sequentially above each particle to be tested according to the target moving path;

[0058] This step is the core step to achieve precise alignment between the indenter and the particle to be tested. The execution scenario is that the testing device has obtained the optimal indenter movement path, and it is necessary to control the pressure testing module to drive the indenter to move sequentially to directly above each particle to be tested along this path, in order to prepare for subsequent focusing positioning and compression testing.

[0059] During execution, the control unit of the testing device first extracts the target plane coordinates (i.e., the position coordinates of the particle in the XY plane) and the Z-axis safety height requirement for each target particle from the target movement path. Then, it controls the XYZ three-axis moving mechanism in the pressure testing module to drive the pressure head to move upward along the Z-axis until the pressure head reaches the preset safety height. This safety height is preset to be higher than the maximum height of all the particles to be tested, and ensures that the pressure head will not collide with the support platform or other particles when moving in the XY plane, avoiding damage to the pressure head or displacement of the particles, and ensuring the safety of the testing device and the sample. After the pressure head stabilizes at the safety height, the control unit controls the XYZ three-axis moving mechanism to drive the pressure head to move at a constant speed in the XY plane according to the trajectory planned in the target movement path. During the movement, the position detection unit collects the plane coordinates of the pressure head center in real time and compares them with the target plane coordinates of the current target particle to be tested in real time for precise calibration.

[0060] When the plane coordinates of the center of the indenter completely coincide with the plane coordinates of the target, the XYZ three-axis moving mechanism stops moving in the XY plane. At this time, the indenter is exactly above the target particle to be tested. Then, following the same process, the target plane coordinates of the next target particle to be tested are extracted in sequence, and the steps of "Z-axis lifting → XY plane movement → precise alignment" are repeated until the indenter moves in sequence to be directly above all the particles to be tested, completing the alignment preparation work for all the particles to be tested.

[0061] The core effect of this step is to achieve automated and precise alignment between the indenter and the particle to be tested, replacing the cumbersome operation of manually controlling the displacement platform for alignment in existing technologies. This avoids the operational errors of manual alignment and ensures that the indenter is always precisely positioned above the particle, providing a guarantee for the accuracy of subsequent indenter pressing tests. At the same time, by setting a safe height along the Z-axis, the risk of collision during the movement of the indenter is effectively avoided, protecting the testing device and the particle to be tested. This solves the technical problems of low efficiency, large errors, and easy collision damage to equipment in existing technologies, further improving the automation level and safety of the testing process.

[0062] S105. For each target particle to be tested, the automatic focusing module is used to focus and position it to determine the height of the target particle's vertex.

[0063] This step is performed when the indenter is directly above the target particle. The height of the particle's apex needs to be precisely determined to provide an accurate reference for the starting position and pressing distance of the indenter, ensuring that pressure is applied precisely from the particle's apex. During execution, for each target particle, the testing device first activates the autofocus module, controlling it to align with the current particle and initiating the autofocus process. The autofocus module's focus adjustment unit gradually adjusts the camera's focus, while the image sharpness detection unit repeatedly acquires images of the target particle and performs sharpness analysis on each acquired image (e.g., calculating image contrast and sharpness) to find the focus position with the highest image sharpness. This focus position is where the camera is precisely aligned with the particle's apex, as the apex is the closest to the camera and the clearest image. Once the clearest focus position is found, the autofocus module stops focusing and, through linkage with the XYZ three-dimensional motion coordinate system, reads the coordinate value of the particle's apex in the Z-axis direction. This coordinate value is the height of the target particle's apex.

[0064] Subsequently, the testing device sends the vertex height of the target particle to the control unit of the pressure testing module, which stores it as the core test parameter of the current target particle to guide the specific actions of the pressure head in subsequent pressing. Then, for the next target particle, the above process is repeated, that is, after the pressure head moves directly above the particle, the automatic focusing module is activated to focus and position, and determine its vertex height, until the vertex height of all target particles is determined and stored.

[0065] The effect of this step is to accurately determine the height of the apex of each target particle to be tested, avoiding the operational errors of manually adjusting the focus to determine the contact zero point in existing technologies. This ensures that pressure is applied precisely from the particle apex when the indenter is pressed down, avoiding test force errors caused by contact zero point deviation. At the same time, the automated operation of the autofocus module replaces the tedious manual focusing steps, improving the efficiency and accuracy of focusing and positioning. It solves the technical problems of low efficiency, large errors, and difficulty in accurately determining the position of the particle apex in existing technologies, laying the foundation for the accurate acquisition of subsequent mechanical property data.

[0066] S106. Based on the height of the target particle apex, control the pressure head to press down until the particle is broken, and record the mechanical performance data. The recorded mechanical performance data shall include at least the crushing force value, crushing displacement, and load displacement curve.

[0067] This step is performed when the indenter is precisely positioned above the target particle to be tested, and the height of the particle's apex has been determined. The compression test can then be initiated, mechanical property data can be collected, and the test of a single particle can be completed.

[0068] During execution, for each target particle to be tested, the control unit of the testing device first calls the target particle vertex height determined in S105, and controls the XYZ three-axis moving mechanism in the pressure testing module to drive the pressure head to move slowly downward along the Z-axis. The moving speed is preset to be uniform to ensure uniform pressure application and avoid test data distortion due to excessive pressure application. During the movement of the pressure head, the force sensor and displacement sensor of the pressure testing module detect the contact state between the pressure head and the particle in real time. When the lower end face of the pressure head just touches the particle vertex (i.e., the Z-axis coordinate of the pressure head is consistent with the height of the target particle vertex), it is regarded as the contact zero point. At this time, the force sensor and displacement sensor start to synchronously record the load (pressure value) applied by the pressure head and the downward displacement of the pressure head.

[0069] Afterwards, the pressure head continues to press down at a constant speed, continuously applying pressure to the particle. During the pressing process, force and displacement sensors collect and record the load value and corresponding pressing displacement at every instant, forming real-time load-displacement data. Until the force sensor detects a sudden and significant drop in the load value, indicating that the target particle has broken and its structure has been damaged, the testing device immediately controls the XYZ three-axis moving mechanism to stop the pressure head from pressing down, completing the mechanical property test of the target particle. After the test, the testing device organizes the collected load and displacement data, extracts the core mechanical property data, including at least the crushing force value, crushing displacement, and load-displacement curve, and correlates these data with the coordinate information of the target particle, test time, and other parameters, storing them in the testing device's database for subsequent querying, analysis, and statistics. Then, for the next target particle, the above process is repeated, i.e., determining its vertex height → controlling the pressure head to press down → collecting and recording mechanical property data, until all target particles have completed mechanical property testing and data recording.

[0070] The core effect of this step is to automate and standardize the mechanical property testing of individual particles, replacing the manual control of the indenter and manual data recording in existing technologies. This avoids errors caused by manual operation and ensures that the testing conditions (indentation speed, contact zero point) for each particle are consistent, making the collected crushing force, crush displacement, load-displacement curves, and other data more accurate and consistent. At the same time, by collecting load and displacement data in real time throughout the entire testing process, the mechanical property characteristics of the particles can be comprehensively and intuitively reflected. This solves the technical problems of incomplete data collection, large errors, and poor consistency in existing manual testing technologies, providing reliable data support for the accurate evaluation of the mechanical properties of single particles of lithium battery materials. It further improves the fully automated testing design and enhances the accuracy and efficiency of the test.

[0071] In the above embodiment, by employing the coordinated linkage of the visual recognition module, the automatic focusing module, and the pressure testing module, and through fully automated technologies such as automated global particle screening, compliant particle positioning, indenter movement path planning, precise alignment of the indenter and particles, accurate determination of particle vertex height, standardized compression testing, and automatic recording of mechanical performance data, the entire testing process is automated. This achieves orderly collaboration among the modules and eliminates the need for manual intervention throughout the entire testing process. It effectively solves the problems of high dependence on manual operation and low testing efficiency in the existing technology for testing the mechanical properties of single lithium battery materials, thereby realizing the full automation and standardization of the mechanical performance testing of single lithium battery materials. This significantly improves testing efficiency and the accuracy and consistency of test data, effectively avoids various interference factors and operational errors in the testing process, and can efficiently adapt to the needs of rapid and accurate testing of massive amounts of single lithium battery materials.

[0072] In some embodiments, automated cleaning of the indenter is also required to prevent residual sample from interfering with subsequent tests. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a schematic diagram of the self-cleaning module structure in the single-particle mechanical property testing device in the embodiments of this application.

[0073] exist Figure 3 The single-particle mechanical property testing device also includes a self-cleaning module, which comprises an alcohol storage bottle, a titration pump, an alcohol titration head, and a filter paper clamping block. This self-cleaning module can be positioned within a preset area to allow the pressure testing module's indenter to quickly align with the filter paper after completing a single-particle mechanical property test without requiring long-distance movement. The alcohol storage bottle stores cleaning alcohol, providing a stable cleaning medium for the self-cleaning process. The titration pump precisely controls the drip rate and amount of alcohol, ensuring uniform wetting of the filter paper to enhance the cleaning effect. The alcohol titration head accurately drips the alcohol output from the titration pump onto the filter paper, avoiding alcohol splashing that could lead to waste or contamination. The filter paper clamping block secures the filter paper and, through reciprocating motion, generates relative friction between the filter paper and the indenter end, physically removing residues adhering to the indenter. The titration pump and filter paper clamping block are connected to the control unit of the single particle mechanical property testing device. The control unit automatically controls the start of the self-cleaning module and the coordinated action of each component according to the trigger signal of the test process, so as to realize the full automation of the cleaning process.

[0074] Specifically, after the mechanical property test of a single target particle is completed and the mechanical property data is recorded, the indenter has finished compressing the current particle. Its end may have particle debris or residue attached to it. If not cleaned, this will directly affect the accuracy of the test data for the next particle. Therefore, before starting the test of the next target particle, in order to ensure testing accuracy and avoid cross-contamination, a self-cleaning process can be initiated:

[0075] The control unit of the single-particle mechanical property testing device controls the XYZ three-axis moving mechanism of the pressure testing module, driving the pressure head to move from the current testing position to directly above the filter paper of the self-cleaning module. During the movement, the pressure head is maintained at a preset safe height to avoid collision with other components. Subsequently, the control unit sends a command to the titration pump, which pumps the alcohol in the bottle at a preset rate. The alcohol is precisely dripped onto the filter paper through the alcohol titration head until the filter paper is evenly wetted. After the filter paper is wetted by alcohol, the control unit controls the pressure head to slowly press down along the Z-axis until the end of the pressure head makes stable contact with the surface of the filter paper. The contact pressure can be preset to ensure effective transmission of friction without damaging the pressure head or the filter paper. Finally, the control unit drives the filter paper clamping block to reciprocate at a preset frequency and stroke, causing continuous relative friction between the filter paper and the end of the pressure head. The residue at the end of the pressure head is removed through the dissolving effect of the alcohol and the physical friction of the filter paper. The cleaning time can be preset to a set duration to ensure that the residue is completely removed. After cleaning, the control unit controls the pressure head to rise to a safe height, waiting to enter the testing process for the next target particle.

[0076] The core effect of this step is the full automation of indenter cleaning, replacing the tedious manual cleaning operations of existing technologies and avoiding data distortion caused by untimely or incomplete manual cleaning. Through the synergistic effect of alcohol wetting and friction cleaning, fine particle residues at the tip of the indenter can be efficiently removed, ensuring the independence of each particle test and the accuracy of the data. At the same time, the self-cleaning process is seamlessly connected with the testing process, and cleaning can be completed without interrupting the test, further improving the continuity and efficiency of the overall test.

[0077] The single-particle mechanical property testing device in the embodiments of this invention is described below from the perspective of hardware processing. Please refer to [link / reference needed]. Figure 4 This is a schematic diagram of the physical structure of a single-particle mechanical property testing device in the embodiments of this application.

[0078] It should be noted that, Figure 4 The structure of the single-particle mechanical property testing device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0079] like Figure 4As shown, the single-particle mechanical property testing device includes a Central Processing Unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in Read-Only Memory (ROM) 402 or a program loaded from storage section 408 into Random Access Memory (RAM) 403, such as performing the methods described in the above embodiments. The RAM 403 also stores various programs and data required for system operation. The CPU 401, ROM 402, and RAM 403 are interconnected via a bus 404. An Input / Output (I / O) interface 405 is also connected to the bus 404.

[0080] The following components are connected to I / O interface 405: input section 406 including audio input devices, push-button switches, etc.; output section 407 including a liquid crystal display (LCD) and audio output devices, indicator lights, etc.; storage section 408 including a hard disk, etc.; and communication section 409 including a network interface card such as a LAN (Local Area Network) card, modem, etc. Communication section 409 performs communication processing via a network such as the Internet. Drive 410 is also connected to I / O interface 405 as needed. Removable media 411, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 410 as needed so that computer programs read from them can be installed into storage section 408 as needed.

[0081] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing computer programs for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 409, and / or installed from removable medium 411. When the computer program is executed by central processing unit (CPU) 401, it performs the various functions defined in the present invention.

[0082] It should be noted that specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0083] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. Each block in a flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those shown in the drawings.

[0084] Specifically, the single-particle mechanical property testing device of this embodiment includes a processor and a memory. The memory stores a computer program. When the computer program is executed by the processor, it implements the automatic testing method for the single-particle mechanical properties of lithium battery materials provided in the above embodiment.

[0085] In another aspect, the present invention also provides a computer-readable storage medium, which may be included in the single-particle mechanical property testing device described in the above embodiments; or it may exist independently and not assembled into the single-particle mechanical property testing device. The storage medium carries one or more computer programs, which, when executed by a processor of the single-particle mechanical property testing device, cause the single-particle mechanical property testing device to implement the automatic testing method for the single-particle mechanical properties of lithium battery materials provided in the above embodiments.

[0086] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0087] As used in the above embodiments, depending on the context, the term "when..." can be interpreted as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if (the stated condition or event) is interpreted as meaning "if determining...", "in response to determining...", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0088] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. An automatic testing method for the mechanical properties of single particles of lithium battery materials, characterized in that, An apparatus for testing the mechanical properties of single particles, the apparatus comprising a vision recognition module, an autofocus module, and a pressure testing module; the pressure testing module comprising an indenter; the method comprising: Based on the test particle requirements input by the user, the visual recognition module determines whether the global particles meet the preset test requirements. If the test requirements are met, then the set of coordinates of the particles to be tested is determined; Plan the target movement path based on the set of coordinates of the particles to be measured; The pressure testing module is controlled to move sequentially above each particle to be tested according to the target movement path; For each target particle to be tested, the automatic focusing module is used for focusing and positioning to determine the height of the target particle's vertex. Based on the height of the target particle apex, the pressure head is controlled to press down until the particle is broken, and mechanical performance data is recorded. The recorded mechanical performance data includes at least the crushing force value, crushing displacement, and load displacement curve. The step of determining whether the global particles meet the preset test requirements through the visual recognition module specifically includes: The test particle requirements are obtained, and the test particle requirements include at least the particle size; The visual recognition module is controlled to perform a panoramic scan of the sample area on the support stage to obtain a global particle distribution image. The contours of each particle in the global particle distribution image are identified using a watershed algorithm. Calculate the physical parameters of each particle, including at least the particle size; Based on the physical parameters, multiple target particles that meet the user's requirements are selected according to the test particle requirements; A secondary quality assessment is performed on each of the target particles to obtain the number of qualified particles. If the number of qualified particles is greater than the preset qualified number threshold, then the total number of particles is determined to have met the test requirements.

2. The method according to claim 1, characterized in that, The step of performing a secondary quality determination on each of the target particles specifically includes: Obtain the mass parameters from the physical parameters, wherein the mass parameters include at least solidity and aspect ratio; Based on the quality parameters, a threshold is determined according to the preset irregular particles to determine the number of non-irregular particles in the target particles; Particles that have no other particles within a set radius around each of the aforementioned non-irregular particles are identified as qualified particles. The number of qualified particles was counted.

3. The method according to claim 1, characterized in that, The pressure testing module also includes an XYZ three-axis movement mechanism, and the step of determining the coordinate set of the particles to be tested specifically includes: Construct an XYZ three-dimensional motion coordinate system; Obtain the center coordinates of multiple pixels for each qualified particle in the global particle distribution image; Based on preset visual calibration parameters, the center coordinates of each pixel are converted into the physical position coordinates of each qualified particle in the XYZ three-dimensional motion coordinate system. By summing up all the physical location coordinates, we obtain the set of coordinates of the particle to be measured.

4. The method according to claim 1, characterized in that, The step of planning the target movement path based on the set of particle coordinates to be measured specifically includes: Obtain the current position coordinates of the pressure head of the pressure testing module; Map the current position coordinates to the XY plane coordinate system where the bearing platform is located to obtain the pressure head plane coordinates; Starting from the coordinates of the pressure head plane, the shortest path planning algorithm is used to calculate the optimal movement order for traversing all coordinate points in the set of coordinates of the particles to be tested, and the target movement path is generated.

5. The method according to claim 1, characterized in that, The step of controlling the pressure testing module to move sequentially above each particle to be tested according to the target movement path specifically includes: The target plane coordinates of each target particle in the target movement path are extracted sequentially. The XYZ three-axis moving mechanism is controlled to drive the pressure head to rise along the Z-axis to a preset safe height; The XYZ three-axis moving mechanism is controlled to drive the pressure head to move in the XY plane until the center of the pressure head coincides with the target plane coordinates.

6. The method according to claim 1, characterized in that, The single-particle mechanical property testing device further includes a self-cleaning module, which comprises an alcohol storage bottle, a titration pump, an alcohol titration head, and a filter paper clamping block. The method further includes: After recording the mechanical performance data, the pressure head is controlled to move above the filter paper of the self-cleaning module; The titration pump is controlled to add alcohol from the alcohol placement bottle onto the filter paper via the alcohol titration head; Control the pressure head to press down until it contacts the filter paper; The filter paper clamping block is controlled to reciprocate, so as to remove the residue at the end of the pressure head through the relative friction between the filter paper and the pressure head.

7. A single-particle mechanical property testing device, characterized in that, The single-particle mechanical property testing device includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to cause the single-particle mechanical property testing device to perform the method as described in any one of claims 1-6.

8. A computer-readable storage medium comprising instructions, characterized in that, When the instruction is executed on the single-particle mechanical property testing device, the single-particle mechanical property testing device performs the method as described in any one of claims 1-6.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is run on the single-particle mechanical property testing device, the single-particle mechanical property testing device performs the method as described in any one of claims 1-6.

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