Battery module full-size optical detection method and system

Abstract

The application provides a battery module full-size optical detection method and system in the technical field of battery module detection, and the method comprises the following steps: in step S10, standard size data of a standard battery module is acquired; in step S20, a servo transplanting mechanism is driven by PLC based on the standard size data to drive two 2D cameras and two 3D cameras to perform three-axis displacement, so as to calibrate the shooting point positions of the standard battery module, generate a shooting path based on each shooting point position, and record the shooting times to be completed when moving to each shooting point position; in step S30, a positioning clamping mechanism is controlled by PLC to clamp a battery module to be detected, and each 2D camera and 3D camera is moved to the corresponding shooting point position based on the shooting path and the shooting times to shoot 2D photos and 3D photos; in step S40, actual size data of the battery module to be detected is calculated based on each 2D photo and 3D photo; and in step S50, a detection report is generated based on the actual size data. The application has the advantages that the precision and efficiency of full-size detection of the battery module are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of battery module testing technology, and in particular to a full-size optical testing method and system for battery modules. Background Technology

[0002] In the new industrial cycle, battery modules (power batteries) have entered the era of large-scale manufacturing. The market's increasing demands for battery capacity and driving range are forcing companies to continuously explore new technologies and processes to reduce manufacturing costs, achieve efficient and stable production, and improve product quality.

[0003] After battery modules are manufactured, not only do their performance indicators need to be tested, but their dimensions also need to be inspected. Traditionally, the dimensions of battery modules are inspected using coordinate measuring machines or manually with vernier calipers. However, this method has the following drawbacks: low accuracy and slow speed of the equipment or methods; the need for manual recording of inspection data, leading to delays in processing; and it cannot meet the needs of large-scale automated production.

[0004] Therefore, how to provide a full-size optical inspection method and system for battery modules to improve the accuracy and efficiency of full-size inspection of battery modules has become an urgent technical problem to be solved. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for full-size optical inspection of battery modules, thereby improving the accuracy and efficiency of full-size inspection of battery modules.

[0006] In a first aspect, the present invention provides a full-size optical inspection method for battery modules, comprising the following steps:

[0007] Step S10: The vision software system acquires the standard size data of the standard battery module input by the touch screen;

[0008] Step S20: Based on the standard size data, the PLC drives the servo transplanting mechanism to perform three-axis displacement in conjunction with two 2D cameras and two 3D cameras to calibrate the shooting points of the standard battery module, generate a shooting path based on each shooting point, and record the number of shots required to move to each shooting point.

[0009] Step S30: The PLC controls the positioning and clamping mechanism to clamp the battery module under test. Based on the shooting path and the number of shots, each 2D camera and 3D camera is moved to the corresponding shooting point to take 2D and 3D photos.

[0010] Step S40: The vision software system calculates the actual size data of the battery module under test based on each of the 2D and 3D photos;

[0011] Step S50: The vision software system generates and stores an inspection report based on the actual size data.

[0012] Furthermore, in step S10, the standard size data includes at least the length, width, height, aperture, hole position, flatness, and end plate distance of the battery module.

[0013] Further, step S20 specifically includes:

[0014] The PLC controls the positioning and clamping mechanism to clamp the standard battery module. After initializing the servo transfer mechanism, it drives the servo transfer mechanism to perform three-axis displacement by linking two 2D cameras and two 3D cameras. This moves the two 3D cameras to the top and bottom of the standard battery module, respectively, and the shooting direction of each 2D camera and 3D camera is facing the standard battery module to calibrate the shooting point of the standard battery module.

[0015] Based on each shooting point, shooting paths for each 2D camera and 3D camera are generated, and the number of shots required for each 2D camera and 3D camera to move to each shooting point is recorded.

[0016] Further, step S30 specifically includes:

[0017] The PLC-controlled positioning and clamping mechanism clamps the battery module under test. After initializing the servo transfer mechanism, based on the shooting path, the servo transfer mechanism moves each 2D camera and 3D camera to the first shooting point to take 2D and 3D photos. After determining that the shooting has been completed based on the number of shots, the servo transfer mechanism moves each 2D camera and 3D camera to the next shooting point until the shooting work at all shooting points is completed.

[0018] Further, step S40 specifically includes:

[0019] After preprocessing each of the 2D photos, the vision software system first performs coarse positioning through feature matching and affine transformation, then obtains the aperture and center coordinates by fitting a circle using a circle-finding tool, reconstructs the coordinate system based on the center coordinates, calculates the length and width of the battery module under test based on the aperture and center coordinates of the holes at both ends, and calculates the hole position degree based on the center coordinates.

[0020] The vision software system calculates the height of the battery module under test based on the height difference between the two 3D photos; selects N points from the 3D photo taken from below the battery module under test, and uses the least squares method to fit the plane to calculate the flatness of the bottom of the battery module under test, where N is a positive integer; and obtains the endplate distance based on the depth information carried by the 3D photo taken from below the battery module under test.

[0021] Secondly, the present invention provides a full-size optical inspection system for battery modules, comprising the following modules:

[0022] The standard size data acquisition module is used by the vision software system to acquire the standard size data of the standard battery module input by the touch screen.

[0023] The shooting point calibration module is used by the PLC to drive the servo transplanting mechanism to perform three-axis displacement based on the standard size data, thereby calibrating the shooting points of the standard battery module, generating a shooting path based on each shooting point, and recording the number of shots required to move to each shooting point.

[0024] The shooting module is used by PLC to control the positioning and clamping mechanism to clamp the battery module under test, and to move each 2D camera and 3D camera to the corresponding shooting point to take 2D and 3D photos based on the shooting path and the number of shooting times.

[0025] The size data calculation module is used by the vision software system to calculate the actual size data of the battery module under test based on the 2D and 3D photos.

[0026] The inspection report generation and storage module is used by the vision software system to generate and store inspection reports based on the actual size data.

[0027] Furthermore, in the standard size data acquisition module, the standard size data includes at least the length, width, height, aperture, hole position, flatness, and end plate distance of the battery module.

[0028] Furthermore, the shooting point calibration module is specifically used for:

[0029] The PLC controls the positioning and clamping mechanism to clamp the standard battery module. After initializing the servo transfer mechanism, it drives the servo transfer mechanism to perform three-axis displacement by linking two 2D cameras and two 3D cameras. This moves the two 3D cameras to the top and bottom of the standard battery module, respectively, and the shooting direction of each 2D camera and 3D camera is facing the standard battery module to calibrate the shooting point of the standard battery module.

[0030] Based on each shooting point, shooting paths for each 2D camera and 3D camera are generated, and the number of shots required for each 2D camera and 3D camera to move to each shooting point is recorded.

[0031] Furthermore, the shooting module is specifically used for:

[0032] The PLC-controlled positioning and clamping mechanism clamps the battery module under test. After initializing the servo transfer mechanism, based on the shooting path, the servo transfer mechanism moves each 2D camera and 3D camera to the first shooting point to take 2D and 3D photos. After determining that the shooting has been completed based on the number of shots, the servo transfer mechanism moves each 2D camera and 3D camera to the next shooting point until the shooting work at all shooting points is completed.

[0033] Furthermore, the size data calculation module is specifically used for:

[0034] After preprocessing each of the 2D photos, the vision software system first performs coarse positioning through feature matching and affine transformation, then obtains the aperture and center coordinates by fitting a circle using a circle-finding tool, reconstructs the coordinate system based on the center coordinates, calculates the length and width of the battery module under test based on the aperture and center coordinates of the holes at both ends, and calculates the hole position degree based on the center coordinates.

[0035] The vision software system calculates the height of the battery module under test based on the height difference between the two 3D photos; selects N points from the 3D photo taken from below the battery module under test, and uses the least squares method to fit the plane to calculate the flatness of the bottom of the battery module under test, where N is a positive integer; and obtains the endplate distance based on the depth information carried by the 3D photo taken from below the battery module under test.

[0036] The advantages of this invention are:

[0037] The shooting points of 2D and 3D cameras are calibrated based on a standard battery module. Shooting paths are generated based on each shooting point, and the number of shots required to reach each shooting point is recorded. Then, based on the shooting paths and the number of shots, each 2D and 3D camera is moved to the corresponding shooting point to capture 2D and 3D photos of the battery module under test. Based on each 2D and 3D photo, the dimensional data of the battery module under test, including actual length, width, height, aperture, hole position, flatness, and end plate distance, are calculated. Based on the actual dimensional data, an inspection report is automatically generated and stored. In other words, non-contact, full-size automatic inspection of the battery module is performed using 2D and 3D cameras, and the inspection report is automatically generated and stored without manual operation, recording, or calculation. Moreover, the inspection accuracy of optical inspection based on 2D and 3D cameras is much higher than that of coordinate measuring machines and vernier calipers, ultimately greatly improving the accuracy and efficiency of full-size inspection of battery modules. Attached Figure Description

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] Figure 1 This is a flowchart of a full-size optical inspection method for battery modules according to the present invention.

[0040] Figure 2 This is a schematic diagram of the structure of a full-size optical inspection system for a battery module according to the present invention. Detailed Implementation

[0041] The technical solution in this application embodiment has the following general idea: non-contact full-size automatic inspection of the battery module is performed based on 2D and 3D cameras, and inspection reports are automatically generated and stored. The inspection accuracy of optical inspection based on 2D and 3D cameras is much higher than that of coordinate measuring machines and vernier calipers, thereby improving the accuracy and efficiency of full-size inspection of the battery module.

[0042] Please refer to Figures 1 to 2 As shown, a preferred embodiment of the full-size optical inspection method for battery modules of the present invention includes the following steps:

[0043] Step S10: The vision software system acquires the standard size data of the standard battery module input by the user through the touch screen;

[0044] Step S20: Based on the standard size data, the PLC drives the servo transplanting mechanism to perform three-axis displacement in conjunction with two 2D cameras and two 3D cameras (3D profilometers) to calibrate the shooting points of the standard battery module. A shooting path is generated based on each shooting point, and the number of shots required to move to each shooting point is recorded. The number of shots is used to verify whether the 2D or 3D camera has completed the shooting work at the corresponding shooting point. For example, if there are shooting points 1, 2, and 3, and each of the three shooting points requires one photo to be taken, but after moving to shooting point 3, it is found that only two photos have been taken, then it can be determined that shooting point 3 has not yet completed the shooting work.

[0045] Step S30: The PLC controls the positioning and clamping mechanism to clamp the battery module under test. Based on the shooting path and the number of shots, each 2D camera and 3D camera is moved to the corresponding shooting point to take 2D and 3D photos.

[0046] Step S40: The vision software system calculates the actual size data of the battery module under test based on each of the 2D and 3D photos;

[0047] Step S50: The vision software system generates and stores an inspection report based on the actual size data; the inspection report includes at least the inspection time, actual size data, standard size data, the difference between the actual size data and the standard size data, and the inspection result; the inspection result is either qualified or unqualified.

[0048] The detection report is hashed to obtain a hash value, and both the detection report and the hash value are encrypted and stored using a preset key. By hashing the detection report, the integrity of the report can be quickly verified, and whether the report has been tampered with can be quickly checked using the hash value. Encryption with the key prevents the report from being intercepted in plaintext, thus greatly ensuring the security of the detection report.

[0049] In step S10, the standard dimension data includes at least the length, width, height, aperture, hole position, flatness, and end plate distance (the height difference between the end plate and the bottom of the battery module).

[0050] Step S20 specifically involves:

[0051] The PLC controls the positioning and clamping mechanism to clamp the standard battery module. After initializing the servo transfer mechanism, it drives the servo transfer mechanism to link two 2D cameras and two 3D cameras to perform three-axis displacement. The 2D cameras are calibrated at nine points, so that the two 3D cameras are moved to the top and bottom of the standard battery module respectively, and the shooting direction of each 2D camera and 3D camera is facing the standard battery module to calibrate the shooting point of the standard battery module.

[0052] Based on the aforementioned shooting locations, shooting paths for each 2D and 3D camera are generated, and the number of shots required for each 2D and 3D camera to move to each shooting location is recorded. In specific implementations, shooting locations can be calibrated based on different battery module models, and corresponding shooting paths and shooting counts can be generated.

[0053] The servo transplanting mechanism is driven by a servo driver, and the PLC converts the servo control of the servo transplanting mechanism into axis control to achieve three-axis linkage of the installed 2D and 3D cameras.

[0054] Step S30 specifically involves:

[0055] The PLC-controlled positioning and clamping mechanism clamps the battery module under test. After initializing the servo transfer mechanism, based on the shooting path, the servo transfer mechanism moves each 2D camera and 3D camera to the first shooting point to take 2D and 3D photos. After determining that the shooting has been completed based on the number of shots, the servo transfer mechanism moves each 2D camera and 3D camera to the next shooting point until the shooting work at all shooting points is completed.

[0056] Step S40 specifically involves:

[0057] After preprocessing each of the 2D photos, the vision software system first performs coarse positioning through feature matching and affine transformation, then obtains the aperture and center coordinates by fitting a circle using a circle-finding tool, reconstructs the coordinate system based on the center coordinates, calculates the length and width of the battery module under test based on the aperture and center coordinates of the holes at both ends, and calculates the hole position degree based on the center coordinates.

[0058] The vision software system calculates the height of the battery module under test based on the height difference between the two 3D photos; selects N points from the 3D photo taken from below the battery module under test, and uses the least squares method to fit the plane to calculate the flatness of the bottom of the battery module under test, where N is a positive integer; and obtains the endplate distance based on the depth information carried by the 3D photo taken from below the battery module under test.

[0059] A preferred embodiment of the full-size optical inspection system for battery modules of the present invention includes the following modules:

[0060] The standard size data acquisition module is used by the vision software system to acquire the standard size data of the standard battery module input by the user through the touch screen.

[0061] The shooting point calibration module is used by the PLC to drive the servo transplanting mechanism to perform three-axis displacement based on the standard size data, linking two 2D cameras and two 3D cameras (3D profilometers) to calibrate the shooting points of the standard battery module. It generates shooting paths based on each shooting point and records the number of shots required to reach each shooting point. The number of shots is used to verify whether the 2D or 3D camera has completed the shooting work at the corresponding shooting point. For example, if there are shooting points 1, 2, and 3, and each of these three points requires one photo to be taken sequentially, but only two photos are taken after moving to shooting point 3, it can be determined that shooting point 3 has not yet completed the shooting work.

[0062] The shooting module is used by PLC to control the positioning and clamping mechanism to clamp the battery module under test, and to move each 2D camera and 3D camera to the corresponding shooting point to take 2D and 3D photos based on the shooting path and the number of shooting times.

[0063] The size data calculation module is used by the vision software system to calculate the actual size data of the battery module under test based on the 2D and 3D photos.

[0064] The inspection report generation and storage module is used by the vision software system to generate and store an inspection report based on the actual size data; the inspection report includes at least the inspection time, actual size data, standard size data, the difference between the actual size data and the standard size data, and the inspection result; the inspection result is either qualified or unqualified.

[0065] The detection report is hashed to obtain a hash value, and both the detection report and the hash value are encrypted and stored using a preset key. By hashing the detection report, the integrity of the report can be quickly verified, and whether the report has been tampered with can be quickly checked using the hash value. Encryption with the key prevents the report from being intercepted in plaintext, thus greatly ensuring the security of the detection report.

[0066] In the standard size data acquisition module, the standard size data includes at least the length, width, height, hole diameter, hole position, flatness, and end plate distance (the height difference between the end plate and the bottom of the battery module).

[0067] The shooting point calibration module is specifically used for:

[0068] The PLC controls the positioning and clamping mechanism to clamp the standard battery module. After initializing the servo transfer mechanism, it drives the servo transfer mechanism to link two 2D cameras and two 3D cameras to perform three-axis displacement. The 2D cameras are calibrated at nine points, so that the two 3D cameras are moved to the top and bottom of the standard battery module respectively, and the shooting direction of each 2D camera and 3D camera is facing the standard battery module to calibrate the shooting point of the standard battery module.

[0069] Based on the aforementioned shooting locations, shooting paths for each 2D and 3D camera are generated, and the number of shots required for each 2D and 3D camera to move to each shooting location is recorded. In specific implementations, shooting locations can be calibrated based on different battery module models, and corresponding shooting paths and shooting counts can be generated.

[0070] The servo transplanting mechanism is driven by a servo driver, and the PLC converts the servo control of the servo transplanting mechanism into axis control to achieve three-axis linkage of the installed 2D and 3D cameras.

[0071] The shooting module is specifically used for:

[0072] The PLC-controlled positioning and clamping mechanism clamps the battery module under test. After initializing the servo transfer mechanism, based on the shooting path, the servo transfer mechanism moves each 2D camera and 3D camera to the first shooting point to take 2D and 3D photos. After determining that the shooting has been completed based on the number of shots, the servo transfer mechanism moves each 2D camera and 3D camera to the next shooting point until the shooting work at all shooting points is completed.

[0073] The dimension data calculation module is specifically used for:

[0074] After preprocessing each of the 2D photos, the vision software system first performs coarse positioning through feature matching and affine transformation, then obtains the aperture and center coordinates by fitting a circle using a circle-finding tool, reconstructs the coordinate system based on the center coordinates, calculates the length and width of the battery module under test based on the aperture and center coordinates of the holes at both ends, and calculates the hole position degree based on the center coordinates.

[0075] The vision software system calculates the height of the battery module under test based on the height difference between the two 3D photos; selects N points from the 3D photo taken from below the battery module under test, and uses the least squares method to fit the plane to calculate the flatness of the bottom of the battery module under test, where N is a positive integer; and obtains the endplate distance based on the depth information carried by the 3D photo taken from below the battery module under test.

[0076] In summary, the advantages of this invention are as follows:

[0077] The shooting points of 2D and 3D cameras are calibrated based on a standard battery module. Shooting paths are generated based on each shooting point, and the number of shots required to reach each shooting point is recorded. Then, based on the shooting paths and the number of shots, each 2D and 3D camera is moved to the corresponding shooting point to capture 2D and 3D photos of the battery module under test. Based on each 2D and 3D photo, the dimensional data of the battery module under test, including actual length, width, height, aperture, hole position, flatness, and end plate distance, are calculated. Based on the actual dimensional data, an inspection report is automatically generated and stored. In other words, non-contact, full-size automatic inspection of the battery module is performed using 2D and 3D cameras, and the inspection report is automatically generated and stored without manual operation, recording, or calculation. Moreover, the inspection accuracy of optical inspection based on 2D and 3D cameras is much higher than that of coordinate measuring machines and vernier calipers, ultimately greatly improving the accuracy and efficiency of full-size inspection of battery modules.

[0078] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A full-size optical inspection method for battery modules, characterized in that: Includes the following steps: Step S10: The vision software system acquires the standard dimension data of the standard battery module input by the touch screen; the standard dimension data includes at least the length, width, height, aperture, hole position, flatness, and end plate distance of the battery module. Step S20: The PLC controls the positioning and clamping mechanism to clamp the standard battery module. After initializing the servo transfer mechanism, the servo transfer mechanism is driven to move two 2D cameras and two 3D cameras in three-axis displacement, so that the two 3D cameras move to the top and bottom of the standard battery module respectively, and the shooting direction of each 2D camera and 3D camera is facing the standard battery module, so as to calibrate the shooting point of the standard battery module. Based on each of the aforementioned shooting locations, shooting paths for each 2D camera and 3D camera are generated, and the number of shots required for each 2D camera and 3D camera to move to each of the aforementioned shooting locations is recorded. Step S30: The PLC controls the positioning and clamping mechanism to clamp the battery module under test. After initializing the servo transfer mechanism, based on the shooting path, the servo transfer mechanism moves each 2D camera and 3D camera to the first shooting point to take 2D and 3D photos. After determining that the shooting has been completed based on the number of shots, the servo transfer mechanism moves each 2D camera and 3D camera to the next shooting point until the shooting work of all shooting points is completed. Step S40: After the vision software system preprocesses each of the 2D photos, it first performs coarse positioning through feature matching and affine transformation, then uses a circle-finding tool to fit a circle to obtain the aperture and center coordinates, reconstructs the coordinate system based on the center coordinates, calculates the length and width of the battery module under test based on the aperture and center coordinates of the holes at both ends, and calculates the hole position degree based on the center coordinates. The vision software system calculates the height of the battery module under test based on the height difference between the two 3D photos. N points are selected from the 3D photo taken from below the battery module under test, and the flatness of the bottom of the battery module under test is calculated by fitting the plane using the least squares method, where N is a positive integer. The endplate distance is obtained based on the depth information carried by the 3D photo taken from below the battery module under test; Step S50: The vision software system generates and stores an inspection report based on the actual size data.

2. A full-size optical inspection system for battery modules, characterized in that: Includes the following modules: A standard size data acquisition module is used by the vision software system to acquire standard size data of the standard battery module input by the touch screen; the standard size data includes at least the length, width, height, aperture, aperture position, flatness, and end plate distance of the battery module; The shooting point calibration module is used by the PLC to control the positioning and clamping mechanism to clamp the standard battery module. After initializing the servo transfer mechanism, it drives the servo transfer mechanism to link two 2D cameras and two 3D cameras to perform three-axis displacement, so that the two 3D cameras move to the top and bottom of the standard battery module respectively, and the shooting direction of each 2D camera and 3D camera is facing the standard battery module, so as to calibrate the shooting point of the standard battery module. Based on each of the aforementioned shooting locations, shooting paths for each 2D camera and 3D camera are generated, and the number of shots required for each 2D camera and 3D camera to move to each of the aforementioned shooting locations is recorded. The shooting module is used by PLC to control the positioning and clamping mechanism to clamp the battery module under test. After initializing the servo transfer mechanism, based on the shooting path, the servo transfer mechanism moves each 2D camera and 3D camera to the first shooting point to take 2D and 3D photos. After determining that the shooting has been completed based on the number of shootings, the servo transfer mechanism moves each 2D camera and 3D camera to the next shooting point until the shooting work of all shooting points is completed. The size data calculation module is used by the vision software system to preprocess each of the 2D photos, firstly to perform coarse positioning through feature matching and affine transformation, then to obtain the aperture and center coordinates by fitting a circle using a circle-finding tool, reconstruct the coordinate system based on the center coordinates, calculate the length and width of the battery module under test based on the aperture and center coordinates of the holes at both ends, and calculate the hole position degree based on the center coordinates. The vision software system calculates the height of the battery module under test based on the height difference between the two 3D photos. N points are selected from the 3D photo taken from below the battery module under test, and the flatness of the bottom of the battery module under test is calculated by fitting the plane using the least squares method, where N is a positive integer. The endplate distance is obtained based on the depth information carried by the 3D photo taken from below the battery module under test; The inspection report generation and storage module is used by the vision software system to generate and store inspection reports based on actual size data.

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