A mechanical arm cooperates with feeding and discharging system for detecting the air tightness of battery pack upper cover

Abstract

The present application relates to the technical field of automatic loading and unloading, and particularly relates to a mechanical arm cooperative loading and unloading system for battery pack upper cover air tightness detection, which comprises a mechanical arm, a base plate installed at the end of the mechanical arm, a vacuum chuck array arranged on the base plate, a non-contact displacement sensor, a visual guidance camera, a controller and a main control unit; each vacuum chuck unit in the vacuum chuck array is connected with the base plate through an independent telescopic driving mechanism and the telescopic stroke can be independently controlled; the visual guidance camera has a known calibration relationship with the mechanical arm reference coordinate system, is used for shooting to obtain the position and posture of the upper cover in the reference coordinate system, and detects the reference position of the tooling; the controller plans the length of each vacuum chuck unit to form a profiled adsorption surface conforming to the back surface of the upper cover according to the upper cover profile data, and adjusts the grabbing track and the placing track accordingly. The present application improves the problem that the flexible adaptive grabbing and the high-precision non-destructive placing are difficult to be considered in the prior art.

Description

Technical Field

[0001] This invention relates to the field of automated loading and unloading technology, specifically to a robotic arm-assisted loading and unloading system for detecting the airtightness of battery pack covers. Background Technology

[0002] As a key structural component of the power battery in new energy vehicles, the airtightness of the battery pack cover directly determines the safety performance and service life of the battery pack. In automated testing production lines, the loading and unloading process is the core step connecting workpiece transportation and airtightness testing. It requires placing the workpiece on the sealing surface of the airtightness testing fixture with sub-millimeter precision to ensure the accuracy of the airtightness test data.

[0003] For automated loading and unloading of thin-walled, large-planar workpieces, the conventional practice in this field is to use a robotic arm in conjunction with a specialized gripping fixture. The rigid fixture corresponds one-to-one with a specific workpiece model, and precise mechanical fitting ensures placement accuracy. This design approach of "ensuring accuracy with rigid fixtures" has long been considered a stable and reliable solution in the industry.

[0004] However, the battery pack cover has a thin-walled structure, and the surface shape and size vary significantly between different models. If the rigid tooling solution described above is used, each model change requires machine downtime to replace the dedicated tooling and readjustment, resulting in a long changeover cycle and failing to meet the needs of multi-variety, small-batch production. While a flexible, adaptive gripping solution, with its adjustable adsorption mechanism compatible with different surfaces, can achieve convenient changeover, the multi-degree-of-freedom adjustable nature of the flexible mechanism introduces additional kinematic chain errors, leading to decreased placement accuracy. The workpiece placement accuracy directly determines the quality of its fit with the sealing surface; poor fit will result in distorted airtightness test data.

[0005] In summary, in the scenario of automated loading and unloading of various thin-walled workpieces, there is a need for a loading and unloading system that can adapt to and be compatible with various types of curved surfaces, and can stably place the workpieces on the sealing surface with sub-millimeter precision. Existing solutions cannot meet these two requirements at the same time. Summary of the Invention

[0006] The purpose of this invention is to provide a robotic arm collaborative loading and unloading system for detecting the airtightness of battery pack covers, so as to improve the problems of long changeover cycles for rigid tooling and limited placement accuracy of flexible solutions in existing automated loading and unloading schemes.

[0007] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution: This invention provides a robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover, comprising: a robotic arm; a substrate mounted at the end of the robotic arm; a vacuum suction cup array disposed on the substrate, the vacuum suction cup array comprising multiple vacuum suction cup units, each of which is connected to the substrate via an independent telescopic drive mechanism, the telescopic stroke of each telescopic drive mechanism being independently controllable; a non-contact displacement sensor mounted on the substrate, used to scan the surface contour of the battery pack cover before gripping to obtain cover contour data; and a vision-guided camera fixedly disposed within the space where the robotic arm is located, having a known calibration relationship with the robotic arm's reference coordinate system, used to photograph the cover in a pre-positioned state before gripping to obtain the actual position and rotation angle of the cover in the robotic arm's reference coordinate system, and to photograph the airtightness detection fixture before placement to obtain the airtightness data. The airtightness testing fixture is positioned at a reference point in the robotic arm's reference coordinate system. A controller, electrically connected to the robotic arm, the non-contact displacement sensor, the vision-guided camera, and each of the telescopic drive mechanisms, plans the extension length of each vacuum suction cup unit based on the surface depth of the upper cover corresponding to the position of each vacuum suction cup unit in the upper cover contour data. This ensures that the suction cup surface of each vacuum suction cup unit forms a contoured adsorption surface that conforms to the curved back surface of the upper cover. The controller also adjusts the robotic arm's gripping trajectory based on the actual position and rotation angle of the upper cover, and adjusts the robotic arm's placement trajectory based on the reference point of the airtightness testing fixture. A main control unit, electrically connected to the robotic arm and the controller, receives a workpiece placement completion signal from the robotic arm and, upon receiving the signal, instructs the airtightness testing fixture to close and starts the airtightness testing instrument for testing.

[0008] According to one embodiment of the present invention, each vacuum suction cup unit in the vacuum suction cup array is independently equipped with a vacuum valve and a vacuum detection module. After the contour adsorption surface is formed, each vacuum suction cup unit independently adjusts the vacuum suction force according to its contact state with the upper cover surface. The vacuum detection module is used to determine the contact state between the workpiece and the sealing surface of the airtightness detection fixture at various points based on the vacuum degree change characteristics generated by each vacuum suction cup unit during the placement process due to the workpiece contacting the sealing surface.

[0009] According to one embodiment of the present invention, the non-contact displacement sensor is a laser triangular displacement sensor, which is installed on the side of the substrate and located outside all the vacuum suction cup units. The robotic arm drives the substrate to carry the laser triangular displacement sensor to perform X and Y direction translational scanning along the surface of the upper cover. The controller calculates the target extension stroke of each vacuum suction cup unit one by one according to the full-area contour data collected by the scan.

[0010] According to one embodiment of the present invention, the telescopic drive mechanism is a miniature electric push rod. The controller calculates the contact pressure by monitoring the real-time operating current of the miniature electric push rod. When the contact pressure reaches a preset value during the placement process, the robotic arm switches to force control mode to maintain a constant downward pressure until the workpiece is firmly seated, forming a dual closed-loop control of displacement monitoring and current pressure feedback.

[0011] According to one embodiment of the present invention, a positioning detection sensor is further provided on the substrate. The positioning detection sensor is electrically connected to the main control unit and is used to confirm that the workpiece has been released. After receiving the workpiece placement completion signal and the workpiece detachment signal from the positioning detection sensor, the main control unit commands the airtightness detection fixture to close.

[0012] According to one embodiment of the present invention, the vision-guided camera takes a first picture before the robotic arm grasps the cover to obtain correction data, and takes a second picture when the robotic arm carrying the cover moves above the airtightness testing station to obtain the reference position of the airtightness testing fixture, thereby realizing secondary vision positioning.

[0013] According to one embodiment of the present invention, the accuracy threshold of the secondary visual positioning is set to ±0.2mm, the calibration error of the visual guidance camera is controlled within ±0.05mm, and the machining and installation tolerance of the positioning pin of the airtightness testing fixture is controlled within ±0.03mm.

[0014] According to one embodiment of the present invention, the main control unit binds the material code of the upper cover with the status signal and timestamp generated during the gripping and detection process of the robotic arm to generate a unique detection record, and synchronously stores it in the local database and the factory MES system.

[0015] According to one embodiment of the present invention, the robotic arm is a six-axis robotic arm, the vacuum suction cup array adopts a 3×6 matrix with a total of 18 groups of vacuum suction cup units, which are evenly arranged with a spacing of 40mm, and the stroke of the micro electric push rod is 0-20mm and the thrust is 5-15N.

[0016] According to one embodiment of the present invention, a signal interlock logic is established between the main control unit and the controller. The signal interlock logic includes at least one of the following interlock conditions: the main control unit allows the robotic arm to perform a grasping action only after the vision-guided camera completes material code reading and the first positioning correction signal is qualified, the contour scanning data acquisition is completed, and the contour adjustment parameters of each vacuum suction cup unit are loaded; the robotic arm is allowed to transfer the workpiece to the airtightness detection station only when the grasping vacuum degree is stable and meets the standard and there is no abnormal adsorption signal; the robotic arm is allowed to perform a pressing and placing action only when the secondary positioning deviation of the vision-guided camera is within the accuracy threshold and the tooling reference is in place signal is valid; and the workpiece placement is determined to be completed and the workpiece placement completion signal is sent only when the displacement stroke is in place, the bonding pressure is qualified, the vacuum release of each vacuum suction cup unit is completed, and the workpiece detachment signal is valid.

[0017] Compared with the prior art, the present invention has the following advantages: This invention unifies the spatial position of the workpiece at the gripping end and the tooling reference position at the placement end under the same robotic arm reference coordinate system for calculation, enabling flexible adaptive gripping and sub-millimeter-level high-precision placement to be achieved collaboratively within the same system. Through the independent extension and retraction drive of each vacuum suction cup unit, the suction cup surface forms a contour-following adsorption surface that conforms to the curved back surface of the workpiece, achieving adaptive compatibility and non-destructive gripping of various workpiece types. Through two-shot positioning by a vision-guided camera under the unified reference coordinate system, a closed-loop visual guidance is formed from the gripping end to the placement end, achieving sub-millimeter-level precise placement of the workpiece. This improves upon the difficulty of simultaneously achieving flexible adaptive gripping and high-precision non-destructive placement in existing solutions, enhancing the accuracy of airtightness testing data and the changeover efficiency of loading and unloading processes. Attached Figure Description

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of an overall system for a robotic arm-assisted loading and unloading system for detecting the airtightness of a battery pack cover, provided as an embodiment of this application.

[0020] Figure 2 A schematic diagram of a system that equips a vacuum suction cup unit with a vacuum valve and a vacuum detection module.

[0021] Figure 3This is a system diagram showing how the main control unit synchronously stores the acquired robotic arm-related signal data to the local database and the factory's MES system.

[0022] The reference numerals in the figure are as follows: 100. Robotic arm; 110. Base plate; 120. Vacuum suction cup array; 121. Vacuum suction cup unit; 122. Telescopic drive mechanism; 130. Non-contact displacement sensor; 140. Vision guidance camera; 150. Controller; 160. Main control unit; 170. Vacuum valve; 180. Vacuum detection module; 190. Position detection sensor; 200. Air tightness testing fixture; 210. Air tightness tester; 220. Local database; 230. Factory MES system; 300. Battery pack cover. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] like Figure 1 As shown in the figure, this specific embodiment provides a robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover, including: 100 robotic arms; The substrate 110 is mounted at the end of the robotic arm 100; A vacuum suction cup array 120 is disposed on a substrate 110. The vacuum suction cup array 120 includes multiple vacuum suction cup units 121. Each vacuum suction cup unit 121 is connected to the substrate 110 through an independent telescopic drive mechanism 122, and the telescopic stroke of each telescopic drive mechanism 122 can be independently controlled. The independent telescopic extension and retraction of each suction cup unit allows the suction cup surface to be discretely and adaptively adjusted according to the actual curved surface shape of the workpiece. Thus, when gripping the top cover 300 of different models of thin-walled battery packs, it can form an adsorption surface that fits against the curved surface of the back of the workpiece, while avoiding localized force concentration and workpiece deformation caused by uniform rigid contact. It should be noted that the suction cup surface of each suction cup unit is itself an elastic material, which can undergo a certain degree of elastic deformation under the vacuum adsorption negative pressure to adapt to the local curved surface. Therefore, "fitting" here refers to the effective sealing contact formed between the suction cup surface and the workpiece surface under vacuum adsorption, rather than a complete seal in an absolute geometric sense.

[0025] A non-contact displacement sensor 130, mounted on a substrate 110, is used to scan the surface contour of the battery pack cover 300 before gripping to obtain cover contour data. The non-contact displacement sensor 130 has the characteristic of acquiring surface geometric information without contacting the workpiece, which can avoid scratches or deformations caused by contact measurements to thin-walled workpieces.

[0026] A vision-guided camera 140 is fixedly installed within the space where the robotic arm 100 is located. It has a known calibration relationship with the robotic arm 100's reference coordinate system. It is used to photograph the top cover in its pre-positioned state before grasping to obtain the actual position and rotation angle of the top cover in the robotic arm 100's reference coordinate system, and to photograph the airtightness testing fixture 200 before placement to obtain the reference position of the airtightness testing fixture 200 in the robotic arm 100's reference coordinate system. This camera can unify the image coordinates to the robotic arm 100's reference coordinate system through hand-eye calibration. All subsequent visual positioning results are calculated within this coordinate system, thus ensuring the accuracy of coordinate transfer throughout the entire process from grasping to placement.

[0027] The controller 150 is electrically connected to the robotic arm 100, the non-contact displacement sensor 130, the vision guidance camera 140, and each telescopic drive mechanism 122. The controller 150 plans the extension length of each vacuum suction cup unit 121 based on the surface depth of the upper cover corresponding to each suction cup unit in the upper cover contour data, so that the suction cup surface of each vacuum suction cup unit 121 forms a contoured adsorption surface that conforms to the curved surface of the upper cover's back. It also adjusts the gripping trajectory of the robotic arm 100 according to the actual position and rotation angle of the upper cover, and adjusts the placement trajectory of the robotic arm 100 according to the reference position of the airtightness testing fixture 200. As the decision-making core of the system, the controller 150 converts the discrete depth data obtained from scanning into target stroke values ​​for each suction cup unit. Multiple points together form a contoured surface that conforms to the curved surface of the workpiece, realizing a data closed loop from "perception" to "execution".

[0028] The main control unit 160, electrically connected to the robotic arm 100 and the controller 150, receives the workpiece placement completion signal sent by the robotic arm 100. Upon receiving the workpiece placement completion signal, it instructs the airtightness testing fixture 200 to close and starts the airtightness tester 210 for testing. The main control unit 160 acts as a signal bridge between the loading / unloading process and the airtightness testing process. It communicates with the PLC of the airtightness testing fixture 200 via hardwiring or an industrial bus to ensure that airtightness testing is only allowed to start after the workpiece has been correctly placed and the robotic arm 100 has retreated from the clearance area.

[0029] In the automated loading and unloading scenario for airtightness testing of battery pack covers (300mm), the workpiece is a thin-walled, large-planar structure with significant differences in surface curvature between different models. Furthermore, the workpiece must be placed on the sealing surface of the airtightness testing fixture (200) with sub-millimeter precision. Existing robotic arm loading and unloading solutions (100mm) offer options where rigid fixtures ensure placement accuracy but lack compatibility with multiple product types, while flexible solutions are compatible with multiple product types but have limited accuracy. It is difficult to simultaneously satisfy both requirements.

[0030] When the system is in operation, the battery pack cover 300 is first transported to the preparatory position. The vision-guided camera 140 takes an initial picture of the cover, and calculates the actual position and rotation angle of the cover in the reference coordinate system of the robotic arm 100 through image processing. The controller 150 adjusts the gripping trajectory of the robotic arm 100 based on this correction data. Subsequently, the robotic arm 100 drive base plate 110, carrying a non-contact displacement sensor 130, performs a traversal scan along the surface of the cover in the X and Y directions to obtain the full-area contour data of the back of the cover. The controller 150 plans the extension length of each telescopic drive mechanism 122 according to the depth of the cover surface at the corresponding position of each vacuum suction cup unit 121, so that the suction cup surfaces of each suction cup unit together form a contoured adsorption surface that fits against the curved surface of the back of the cover, and then performs vacuum adsorption gripping. After grasping, the robotic arm 100 carries the top cover to the airtightness testing station. The vision-guided camera 140 takes a second picture of the airtightness testing fixture 200 to obtain the reference position of the airtightness testing fixture 200 in the reference coordinate system of the robotic arm 100. Based on this, the controller 150 adjusts the placement trajectory to accurately place the top cover inside the airtightness testing fixture 200. During placement, the robotic arm 100 switches to force control mode, maintaining a constant downward pressure until the workpiece is firmly seated, and then the vacuum suction cup is released. After the positioning detection sensor 190 confirms that the workpiece has been removed, the robotic arm 100 sends a workpiece placement completion signal to the main control unit 160. The main control unit 160 then instructs the airtightness testing fixture 200 to close and starts the airtightness tester 210 for testing.

[0031] like Figure 2As shown, in the workpiece contour data acquired by the non-contact displacement sensor 130, the depth value of the corresponding position of each suction cup unit is used as the target stroke of the telescopic drive mechanism 122 of that unit. The controller 150 controls the independent operation of each telescopic drive mechanism 122, and the multi-point discrete suction cup surfaces together form a contoured adsorption surface that fits against the curved surface of the workpiece. During adsorption, since the workpiece is a non-uniform curved surface, the contact state of each suction cup unit is different. The vacuum valve 170 and vacuum detection module 180 independently configured for each suction cup unit can monitor their respective vacuum levels in real time. After the contoured adsorption surface is formed, each vacuum valve 170 independently adjusts the vacuum suction force of the corresponding suction cup unit according to its contact state with the upper cover surface—the suction force is appropriately reduced where the contact is tight and appropriately increased where the contact is shallow, thereby achieving large-area distributed uniform adsorption on the entire non-uniform curved surface, effectively avoiding adsorption deformation of thin-walled workpieces caused by localized concentration of suction force.

[0032] During placement, the thin-walled workpiece, under its own weight and the downward pressure of the robotic arm 100, fully adheres to the surfaces of each suction cup. When a certain area on the lower surface of the workpiece contacts the sealing surface of the airtightness testing fixture 200, the upward supporting reaction force applied by the sealing surface causes that area of ​​the workpiece to undergo a slight upward elastic deflection. This deflection is transmitted to the adsorption area of ​​the corresponding suction cup unit, resulting in a local increase in the sealing gap between the suction cup and the workpiece surface, a decrease in sealing performance, and a subsequent decrease in the vacuum level of that unit. This decreasing trend differs significantly from the stable vacuum level when the workpiece is suspended, and can be distinguished by the descent rate or threshold. Based on this, the vacuum detection module 180 of each suction cup unit determines the contact state between different parts of the workpiece and the sealing surface of the airtightness testing fixture 200, achieving distributed sensing of placement quality.

[0033] This system resolves the physical contradiction between flexible adaptive gripping and high-precision non-destructive placement within a single system by unifying the visual guidance reference and coordinating the contour-guided telescopic suction cup array: the visual guidance camera 140 unifies the workpiece coordinates at the gripping end and the tooling coordinates at the placement end into the reference coordinate system of the robotic arm 100, eliminating the accumulation of errors in the coordinate transfer chain; the contour-guided telescopic suction cup array fits the workpiece surface through multi-point discrete telescopic fitting, achieving compatibility with multiple product types, and avoiding localized stress deformation of thin-walled workpieces through large-area uniform adsorption, eliminating the need to change tooling when changing types, and the placement accuracy can be stably controlled within ±0.2mm.

[0034] Based on the aforementioned solution that has already achieved non-contact scanning functionality, this embodiment designs the non-contact displacement sensor 130 as follows: The non-contact displacement sensor 130 is a laser triangular displacement sensor, mounted on the side of the substrate 110 and located outside all vacuum suction cup units 121. The robotic arm 100 drives the substrate 110 to carry the laser triangular displacement sensor and perform X and Y-axis translational scanning along the surface of the upper cover. The controller 150 calculates the target extension stroke of each vacuum suction cup unit 121 based on the full-area contour data collected by the scan. This sensor is installed on the periphery of the suction cup array and does not occupy the suction cup mounting position. The scanning path is determined by the movement trajectory of the robotic arm 100, which can completely cover the workpiece adsorption area. There is no need to integrate displacement sensing elements inside each suction cup unit; full-point contour acquisition can be achieved by relying on a single sensor for full-area scanning.

[0035] Building upon the aforementioned effects, this design replaces the array-type built-in sensing scheme with a mechanical traversal scanning of a single external sensor, simplifying the mechanical structure and electrical wiring of the vacuum chuck unit 121 while ensuring the integrity and consistency of the contour data.

[0036] Based on the previous solution that has achieved multi-variety adaptive contour grasping, in order to accurately determine the workpiece's settling status on the inspection fixture and avoid overpressure damage, this embodiment designs the telescopic drive mechanism 122 and the placement control method as follows: The telescopic drive mechanism 122 is a miniature electric actuator. The controller 150 calculates the contact pressure by monitoring the real-time operating current of the miniature electric actuator. During placement, when the contact pressure reaches a preset value, the robotic arm 100 switches to force control mode, maintaining a constant downward pressure until the workpiece is firmly seated, forming a dual closed-loop control of displacement monitoring and current-pressure feedback. The miniature electric actuator is driven by a DC motor, and the motor current is directly proportional to the output torque. The actuator's thrust can be indirectly measured through the real-time operating current, eliminating the need for an additional pressure sensor to identify the workpiece's contact and clamping state. The force control mode of the robotic arm 100 supports wide-range pressure adjustment. Conventional thin-walled workpieces can be held with a constant downward pressure to ensure complete contact between the workpiece and the sealing surface. The criteria for "firmly seated" are: the downward pressure reaches a preset constant value and is maintained continuously, while the vacuum detection module 180 of each suction cup unit monitors the vacuum changes during placement, indicating that all parts of the workpiece have contacted the sealing surface.

[0037] Building upon the aforementioned effects, this design replaces the independent pressure sensor with current detection, reducing the number of sensing elements while ensuring the accuracy of the fit determination. At the same time, dual closed-loop control ensures that the placement process is shock-free and the workpiece is properly seated without damage.

[0038] To reliably confirm the completion status of workpiece placement and ensure safe interlocking between the loading / unloading process and the inspection process, this embodiment designs the sensor configuration on the substrate 110 and the signal logic of the main control unit 160 as follows: A positioning detection sensor 190 is also provided on the substrate 110. The positioning detection sensor 190 is electrically connected to the main control unit 160 and is used to confirm that the workpiece has been released. After receiving the workpiece placement completion signal and the workpiece detachment signal from the positioning detection sensor 190, the main control unit 160 commands the airtightness detection fixture 200 to close. The positioning detection sensor 190 can be a photoelectric sensor or an inductive proximity switch, and is mounted on the substrate 110 to sense whether the workpiece has completely detached from the suction cup surface. The dual-signal confirmation mechanism of the main control unit 160 ensures that the airtightness detection fixture 200 is only allowed to close after the workpiece has been completely released and the robotic arm 100 has retreated to the clearance area.

[0039] Building upon the aforementioned effects, this design further enhances the safety and reliability of the loading and unloading process through a dual-signal handshake between the position detection sensor 190 and the main control unit 160.

[0040] To achieve high-precision guidance in grasping and placing positions, the working timing of the visual guidance camera 140 in this embodiment is designed as follows: The vision-guided camera 140 takes a first shot before the robotic arm 100 grasps the top cover to obtain correction data. A second shot is taken when the robotic arm 100, carrying the top cover, moves above the airtightness testing station to obtain the reference position of the airtightness testing fixture 200, achieving secondary visual positioning. The first shot addresses the question of "where is the workpiece," obtaining the actual position and orientation of the workpiece relative to the robotic arm 100's reference coordinate system, used to correct the grasping trajectory. The second shot addresses the question of "where to place it," obtaining the reference position of the airtightness testing fixture 200, used to correct the placement trajectory. Both positioning operations are calculated within the same robotic arm 100 reference coordinate system, ensuring consistency in coordinate transfer from grasping to placement.

[0041] Building upon the aforementioned effects, this design achieves spatial positioning of the grasping and placing ends using the same visual guidance camera within 140 minutes, realizing a closed-loop visual guidance throughout the entire process, with placement accuracy stably controlled within ±0.2mm.

[0042] To ensure the accuracy of secondary vision positioning from a baseline perspective, the tolerances of the vision system and tooling in this embodiment are designed as follows: The accuracy threshold for secondary visual positioning is set at ±0.2mm, the calibration error of the visual guidance camera 140 is controlled within ±0.05mm, and the machining and installation tolerance of the positioning pins of the airtightness testing fixture 200 is controlled within ±0.03mm. The calibration accuracy of the vision system and the machining accuracy of the fixture are the two benchmarks for positioning accuracy, and they must be matched to achieve sub-millimeter-level overall placement accuracy. Both the visual calibration error and the fixture tolerance are controlled to levels far below the placement accuracy threshold, ensuring sufficient engineering margin for the final placement accuracy through error distribution.

[0043] Based on the aforementioned effects, this design controls error propagation from two benchmark sources: the vision system and the mechanical tooling, providing an engineering guarantee for the accuracy threshold of secondary vision positioning.

[0044] like Figure 3 As shown, to achieve end-to-end traceability of production data, the data processing function of the main control unit 160 is designed as follows in this embodiment: The main control unit 160 binds the material code of the upper cover with the status signals and timestamps generated during the gripping, placing, and inspection process of the robotic arm 100, generating a unique inspection record, which is simultaneously stored in the local database 220 and the factory MES system 230. The material code can be synchronously decoded and obtained by the vision-guided camera 140 during the first shot, eliminating the need for manual scanning and input. The incoming positioning data, full-area contour scanning data, contour adjustment parameters of each suction cup, placement and bonding pressure data, airtightness test results, and timestamps of each process for each workpiece are all archived one-to-one with the material code, realizing full-process data binding from workpiece loading to inspection unloading.

[0045] Building upon the aforementioned effects, this design unifies the physical actions of the loading and unloading process with the detection data flow, eliminating the risk of material mixing caused by mismatch between material codes and detection data in traditional manual loading and unloading.

[0046] To achieve the quantitative implementation of specific engineering parameters, the specifications of the robotic arm 100 and the suction cup array are designed as follows in this embodiment: The robotic arm 100 is a six-axis robotic arm. The vacuum suction cup array 120 uses a 3×6 matrix of 18 vacuum suction cup units 121, evenly spaced at 40mm intervals. The miniature electric actuator has a stroke of 0–20mm and a thrust of 5–15N. The six-axis robotic arm 100 has sufficient spatial freedom to complete complex transfer trajectories from the preparatory position to the inspection station. The configuration of 18 suction cup units in a 3×6 matrix can completely cover the adsorption area of ​​a conventional battery pack cover 300, and the 40mm spacing strikes a balance between adsorption force and coverage density. The adjustable stroke of 0–20mm adapts to the surface differences between different models of covers, and the thrust range of 5–15N provides sufficient adsorption pre-tightening force without deforming thin-walled workpieces.

[0047] Based on the aforementioned effects, this design provides specific parameter basis for the standardized implementation of the system, while retaining the flexibility to adjust each parameter within its range.

[0048] To ensure the uniqueness and security of equipment operation and testing processes, this embodiment designs the signal interaction logic between the main control unit 160 and the controller 150 as follows: A signal interlock logic is established between the main control unit 160 and the controller 150, which includes at least one of the following interlock conditions: Only after the vision-guided camera 140 has completed reading the material code and the first positioning correction signal is qualified, the contour scanning data acquisition is completed, and the contour adjustment parameters of each vacuum suction cup unit 121 have been loaded, will the main control unit 160 allow the robotic arm 100 to perform the grasping action. The robotic arm 100 is only allowed to transfer the workpiece to the airtightness testing station when the vacuum level is stable and meets the standard and there are no abnormal adsorption signals. The robotic arm 100 is only allowed to perform the pressing and placing action when the secondary positioning deviation of the vision guidance camera 140 is within the accuracy threshold and the tooling reference is in place signal is valid. The workpiece placement is determined to be complete and a workpiece placement completion signal is sent only when the displacement stroke is in place, the bonding pressure is up to standard, the vacuum release of each vacuum suction cup unit 121 is completed, and the workpiece detachment signal is valid.

[0049] This signal interlock logic breaks down the loading and unloading process into several strictly ordered steps, with each step requiring the completion signal of the previous step as a necessary condition for activation. When any interlock condition is not met, the robotic arm 100 maintains its current state and waits for exception handling.

[0050] Building upon the aforementioned effects, this design upgrades the loading and unloading process into a fully automated and controlled process through a signal interlock mechanism, ensuring the consistency and repeatability of airtightness testing.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. 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. All such modifications or substitutions should be covered within the protection scope of this application, and should not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A robotic arm-assisted loading and unloading system for detecting the airtightness of battery pack covers, characterized in that, include: Robotic arm (100); A substrate (110) is mounted at the end of the robotic arm (100); A vacuum suction cup array (120) is disposed on the substrate (110). The vacuum suction cup array (120) includes multiple vacuum suction cup units (121). Each vacuum suction cup unit (121) is connected to the substrate (110) through an independent telescopic drive mechanism (122). The telescopic stroke of each telescopic drive mechanism (122) can be controlled independently. A non-contact displacement sensor (130) is mounted on the substrate (110) for scanning the surface contour of the battery pack cover (300) before gripping to obtain cover contour data. A visual guidance camera (140) is fixedly installed in the space where the robotic arm (100) is located. It has a known calibration relationship with the reference coordinate system of the robotic arm (100). It is used to take pictures of the upper cover in the preparatory position before grasping to obtain the actual position and rotation angle of the upper cover in the reference coordinate system of the robotic arm (100), and to take pictures of the air tightness testing fixture (200) before placement to obtain the reference position of the air tightness testing fixture (200) in the reference coordinate system of the robotic arm (100). The controller (150) is electrically connected to the robotic arm (100), the non-contact displacement sensor (130), the visual guidance camera (140), and each of the telescopic drive mechanisms (122). The controller (150) plans the extension length of each vacuum suction cup unit (121) according to the depth of the surface of the upper cover corresponding to the position of each vacuum suction cup unit (121) in the upper cover contour data, so that the suction cup surface of each vacuum suction cup unit (121) forms a contoured adsorption surface that fits against the curved surface of the back of the upper cover. The controller (150) adjusts the gripping trajectory of the robotic arm (100) according to the actual position and rotation angle of the upper cover, and adjusts the placement trajectory of the robotic arm (100) according to the reference position of the airtightness testing fixture (200). The main control unit (160) is electrically connected to the robotic arm (100) and the controller (150), and is used to receive the workpiece placement completion signal sent by the robotic arm (100), and after receiving the workpiece placement completion signal, instruct the airtightness testing fixture (200) to close and start the airtightness tester (210) to perform the test.

2. The robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, Each vacuum suction cup unit (121) in the vacuum suction cup array (120) is independently equipped with a vacuum valve (170) and a vacuum detection module (180). After the contour adsorption surface is formed, each vacuum suction cup unit (121) independently adjusts the vacuum suction force according to its contact state with the upper cover surface. The vacuum detection module (180) is used to determine the contact state between the workpiece and the sealing surface of the airtightness testing fixture (200) at various points based on the vacuum degree change characteristics generated by each vacuum suction cup unit (121) during the placement process due to the workpiece contacting the sealing surface.

3. The robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, The non-contact displacement sensor (130) is a laser triangular displacement sensor, which is installed on the side of the substrate (110) and located outside all the vacuum suction cup units (121). The robotic arm (100) drives the substrate (110) to carry the laser triangular displacement sensor to perform X and Y direction translational scanning along the surface of the upper cover. The controller (150) calculates the target extension stroke of each vacuum suction cup unit (121) according to the full-area contour data collected by the scan.

4. The robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, The telescopic drive mechanism (122) is a miniature electric push rod. The controller (150) calculates the contact pressure by monitoring the real-time working current of the miniature electric push rod. When the contact pressure reaches the preset value during the placement process, the robotic arm (100) switches to force control mode to maintain a constant downward pressure until the workpiece is firmly seated, forming a dual closed-loop control of displacement monitoring and current pressure feedback.

5. A robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, The substrate (110) is also provided with a positioning detection sensor (190), which is electrically connected to the main control unit (160) and is used to confirm that the workpiece has been released. After receiving the workpiece placement completion signal and the workpiece detachment signal from the positioning detection sensor (190), the main control unit (160) commands the airtightness detection fixture (200) to close.

6. A robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, The vision guidance camera (140) takes a first shot before the robotic arm (100) grabs the cover to obtain correction data, and takes a second shot when the robotic arm (100) carries the cover to the airtightness testing station to obtain the reference position of the airtightness testing fixture (200), thus realizing secondary vision positioning.

7. A robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 6, characterized in that, The accuracy threshold of the secondary visual positioning is set to ±0.2mm, the calibration error of the visual guidance camera (140) is controlled within ±0.05mm, and the machining and installation tolerance of the positioning pin of the airtightness testing fixture (200) is controlled within ±0.03mm.

8. A robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, The main control unit (160) binds the material code of the cover to the status signal and timestamp generated by the robotic arm (100) during the gripping, release and detection process, generates a unique detection record, and synchronously stores it in the local database (220) and the factory MES system (230).

9. A robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 4, characterized in that, The robotic arm (100) is a six-axis robotic arm. The vacuum suction cup array (120) adopts a 3×6 matrix with a total of 18 groups of vacuum suction cup units (121), which are evenly arranged with a spacing of 40mm. The stroke of the micro electric push rod is 0-20mm and the thrust is 5-15N.

10. A robotic arm collaborative loading and unloading system for detecting the airtightness of a battery pack cover according to claim 1, characterized in that, A signal interlock logic is established between the main control unit (160) and the controller (150), and the signal interlock logic includes at least one of the following interlock conditions: The main control unit (160) only allows the robotic arm (100) to perform the grasping action after the visual guidance camera (140) completes the material code reading and the first positioning correction signal is qualified, the contour scanning data acquisition is completed, and the contour adjustment parameters of each vacuum suction cup unit (121) are loaded. The robotic arm (100) is only allowed to transfer the workpiece to the airtightness testing station when the vacuum level is stable and meets the standard and there is no abnormal adsorption signal. The robotic arm (100) is allowed to perform the pressing and placing action only when the secondary positioning deviation of the visual guidance camera (140) is within the accuracy threshold and the tooling reference is in place signal is valid; The workpiece placement is determined to be complete and the workpiece placement completion signal is sent only when the displacement stroke is in place, the bonding pressure is up to standard, the vacuum release of each vacuum suction cup unit (121) is completed, and the workpiece detachment signal is valid.

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