White vehicle body welding seam polishing system and method

Abstract

The invention provides a body-in-white welding seam polishing system and method. The system comprises a rack, a polishing device and a welding seam detection device, wherein the polishing device and the welding seam detection device are mounted on the rack; wherein the welding seam detection device is used for detecting a body reference surface of a target area of a body in white and a to-be-polished welding seam so as to obtain the position and height of the to-be-polished welding seam; the grinding amount of the weld joint is obtained based on the height of the to-be-ground weld joint and the target height; the grinding device comprises a mechanical arm and a grinding head, the grinding head is installed on the mechanical arm, and the grinding device is used for conducting primary grinding on the to-be-ground weld joint based on the position and the grinding amount of the to-be-ground weld joint; the weld joint detection device is further used for detecting the weld joint to be ground after the weld joint to be ground is ground for the first time till the weld joint to be ground reaches the target height. An existing manual grinding mode can be replaced, the grinding process is guided through welding seam measurement, the grinding result is detected through welding seam detection, errors in manual operation are reduced, and the quality and consistency of the welding seam surface are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile manufacturing, and in particular to a body-in-white weld grinding system and method. Background Art

[0002] Currently, brazing techniques, such as laser brazing and MIG welding, are widely used in body-in-white (BIW) manufacturing. Brazing utilizes a brazing filler metal with a lower melting point than the parent metal, allowing the liquid filler metal to fill gaps between the parent metals. Brazing creates a weld seam at the base metal joint. This raised weld seam can affect the smoothness of the part, necessitating polishing.

[0003] In vehicle manufacturing, to achieve a better seal and appearance at the body-in-white (BIW) taillight corners, MIG welding and polishing are required. Because the polished welds must meet the appearance and sealing requirements of the taillight corners, high polishing accuracy and quality are required. The current BIW taillight corner polishing process relies primarily on manual visual inspection and repair. This requires ensuring weld polishing quality and appearance, particularly avoiding over-polishing. However, manual polishing results in a poor working environment and a low automation rate.

[0004] Currently, there are weld grinding equipment on the market that uses grinding wheels or belts, but most of them are presented in the form of grinding workbenches or fixed workstations. They are only suitable for automatic grinding of simple flat or curved surfaces and have low requirements for grinding accuracy. Some grinding equipment does not have weld detection devices, or lacks measuring devices but cannot identify the weld thickness and thus determine the amount of weld grinding. The grinding environment of the car body in white is complex, especially the grinding of the taillight corner area. The weld structure in this area is complex, the surface shape is irregular, and high-precision grinding of three surfaces is required. The grinding area is small and the weld is short, so more precise control is required. The current market lacks effective taillight angle measurement, grinding and re-inspection solutions, and it is impossible to achieve automated grinding of taillight corners. Summary of the Invention

[0005] In view of this, an embodiment of the present invention provides a body-in-white weld grinding system and method to eliminate or improve one or more defects in the prior art.

[0006] In a first aspect, the present invention provides a body-in-white weld grinding system, the weld grinding system comprising: a frame and a grinding device and a weld detection device mounted on the frame; wherein the weld detection device is used to detect the body reference surface and the weld to be ground in the target area of ​​the body-in-white to obtain the position and height of the weld to be ground; and is also used to obtain the grinding amount of the weld based on the height of the weld to be ground and the target height; the grinding device comprises a robotic arm and a grinding head, the grinding head is mounted on the robotic arm, and the grinding device is used to perform an initial grinding of the weld to be ground based on the position and the grinding amount; the weld detection device is also used to detect the weld to be ground again after the initial grinding is completed until the weld to be ground obtains the target height.

[0007] In some embodiments, the weld detection device includes a contour sensor that can emit linear laser to obtain laser point cloud data of the target area; or, the weld detection device includes a visual sensor and a distance sensor for obtaining weld detection of the target area through visual recognition.

[0008] In some embodiments, the frame includes a connecting frame and a connecting rod, the grinding device is installed on the connecting frame, and the connecting frame is installed on the robotic arm through the connecting rod; the grinding device also includes a floating force-controlled grinding unit, the grinding head is installed on the connecting frame through the floating force-controlled grinding unit, and the grinding head also includes a grinding plate at its end.

[0009] In some embodiments, the weld grinding system also includes a dustproof device, which includes a dustproof cover shell, a dustproof cover cover and a cover opening and closing control structure. The weld detection device is installed in a closed box composed of the dustproof cover shell and the dustproof cover cover; the cover opening and closing control structure is used to control the dustproof cover cover to remain open when the weld detection device is detecting the target area of ​​the white body, and to remain closed when the grinding device is performing weld grinding; the dustproof device is installed on the connecting frame and is located on one side of the grinding device.

[0010] In some embodiments, the weld grinding system also includes a passive limiting device, which includes a limiting rod and a telescopic mechanism, wherein the end of the limiting rod exceeds the end of the grinding head or is flush with it; the passive limiting device is installed on the other side of the grinding head; the telescopic mechanism is used to adjust the limiting distance of the limiting rod, and when the end of the limiting rod contacts the surface of the white body, the grinding device is configured so that the grinding head stops rotating or the robotic arm controls the grinding head to move away from the white body.

[0011] In some embodiments, the weld grinding system further includes an active limiting unit, which is used to limit the movement trajectory of the robotic arm through the shortest distance from the grinding head to the surface of the body-in-white.

[0012] In some embodiments, the weld grinding system further includes a tool changing device, which is used to install at least one new grinding head or grinding sheet; the tool changing device is used to control the grinding head to move to a tool changing position by the robotic arm and automatically replace the new grinding head or grinding sheet when the grinding sheet of the grinding head is consumed to the point where it cannot complete the grinding work.

[0013] In some embodiments, the weld grinding system also includes a data storage module; the data storage module is used to store and record the vehicle number, weld inspection results and weld grinding results of each white body, and the weld grinding results include over-grinding; the data storage module is also used to record the consumption and inventory of the grinding head.

[0014] In a second aspect, the present invention also provides a method for grinding a body-in-white weld, the implementation of which is based on the aforementioned weld grinding system, and the method includes: detecting the body reference surface and the weld to be ground in the target area of ​​the body-in-white by the weld detection device to obtain the position and height of the weld to be ground; obtaining the grinding amount of the weld based on the height of the weld to be ground and the target height; controlling the grinding device to perform initial grinding on the weld to be ground based on the position of the weld to be ground and the grinding amount; after the initial grinding of the weld to be ground is completed, using the weld detection device to detect the weld; if the actual height of the weld is still greater than the target height, controlling the grinding device to continue grinding it until the weld to be ground reaches the target height.

[0015] In some embodiments, the method further includes: during the grinding process of the grinding device, controlling the depth of the grinding head by a passive limiting device, and if the end of the limiting rod contacts the surface of the white body, controlling the grinding head to stop rotating or controlling the grinding head by the robotic arm to move away from the white body; and / or, during the grinding process of the grinding device, by detecting the shortest distance from the grinding head to the white body surface, the active limiting unit limits the movement trajectory of the robotic arm.

[0016] The body-in-white weld grinding system and method in the embodiment of the present invention replaces traditional manual grinding through the coordinated work of a robotic arm and a weld detection device, greatly improving grinding accuracy and production efficiency. Since the detection and grinding of welds in the present invention are automated, the amount of each round of grinding can be precisely controlled, avoiding inconsistent standards and quality fluctuations caused by differences in experience in manual grinding. Automated grinding not only increases grinding speed, but also significantly reduces human errors and the time required for repeated corrections, thereby effectively shortening the production cycle. By accurately calculating the amount of each grinding, the present invention can effectively control the consumption of consumables such as grinding discs, avoid excessive consumption, and maintain a consistent grinding effect over a long period of time.

[0017] Additional advantages, objects, and features of the present invention will be set forth in part in the following description and will become apparent to those skilled in the art upon examination of the following or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structures particularly pointed out in the description and drawings.

[0018] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are intended to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are merely for the purpose of illustrating the principles of the present invention. To facilitate the illustration and description of certain portions of the present invention, corresponding portions in the drawings may be exaggerated, that is, may be larger than other components in an exemplary device actually manufactured according to the present invention. In the drawings:

[0020] Figure 1 FIG. 1 is a partial structural diagram of a body-in-white weld grinding system according to an embodiment of the present invention.

[0021] Figure 2 This is a flowchart of a method for grinding a body-in-white weld seam in one embodiment of the present invention.

[0022] Figure numerals: 1. Floating force-controlled grinding unit; 2. Grinding head; 3. Grinding disc; 4. Quick-connect structure; 5. Contour sensor; 6. Dust cover housing; 7. Dust cover cover; 8. Limit rod; 9. Electric cylinder; 10. Linear motor; 11. Connecting frame; 12. Connecting rod. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0024] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show structures and / or processing steps closely related to the solutions according to the present invention, while other details that are not closely related to the present invention are omitted.

[0025] It should be emphasized that the term "include / comprises" when used herein refers to the existence of features, elements, steps or components, but does not exclude the existence or addition of one or more other features, elements, steps or components.

[0026] It should also be noted that, unless otherwise specified, the term "connection" herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0028] Existing technologies primarily rely on manual grinding of taillight corner welds, failing to automate weld grinding. Manual grinding is time-consuming, and visual inspection standards are difficult to standardize, making it difficult to control grinding disc consumption. Existing automated grinding equipment is unable to measure and inspect taillight corner welds on vehicle bodies in white (BIW), lacking effective implementation options. This makes it difficult to address complex structures, high precision, short weld lengths, and multi-surface grinding scenarios. Existing technologies are unable to calculate weld grinding volume, and it is difficult to identify grinding defects on complex surface structures after grinding.

[0029] To address or alleviate the various problems existing in the aforementioned prior art, the present invention provides a body-in-white weld seam grinding system and method to replace traditional manual grinding methods. This invention proposes a digital, intelligent, and automated grinding method that can improve production efficiency and the production environment. Through automated grinding, the production cycle can be effectively controlled, and the consumption of consumables such as grinding heads can be controlled. Furthermore, weld seam measurement can be used to guide the grinding process, and weld seam inspection can be used to verify the grinding results, generating historical data for data traceability.

[0030] In a first aspect, an embodiment of the present invention provides a body-in-white weld grinding system, such as Figure 1The weld grinding system includes a frame, a grinding device mounted on the frame, a weld detection device, and the like. The weld detection device is used to detect the body reference surface and the weld to be ground in the target area of ​​the body-in-white (BIW) to obtain the position and height of the weld to be ground; it is also used to determine the grinding amount of the weld based on the height of the weld to be ground and the target height. The grinding device includes a robotic arm and a grinding head 2, which is mounted on the robotic arm. The grinding device is used to perform an initial grinding of the weld to be ground based on its position and the grinding amount. The weld detection device is also used to perform further testing on the weld to be ground after the initial grinding is completed until the weld to be ground reaches the target height.

[0031] In the above embodiment, the weld inspection device detects the relative position of the weld seam to be ground in a target area of ​​the body-in-white (BIW) (BW) (such as the taillight corner) between the body reference surface and the weld to be ground. This determines the precise position and height of the weld seam. The difference between the detected weld seam height and the target height is used to calculate the required grinding distance, thereby accurately guiding the grinding device. A robotic arm is used to position and precisely control the motion trajectory of the grinding head 2, ensuring high-precision grinding within the complex taillight corner area. The grinding head 2 can be mounted on the robotic arm to perform the actual grinding task, precisely following the data provided by the weld inspection device.

[0032] In the above embodiment, based on the preliminary inspection data of the weld, the grinding device first performs the initial grinding to remove irregularities on the weld surface and achieve a predetermined grinding amount. After the initial grinding is completed, the weld inspection device again detects the height and shape of the weld. If it is found that the grinding does not meet the target height, the system will automatically provide feedback to the grinding device for fine adjustment. Through continuous inspection and trimming, it is ensured that the height and shape of the weld gradually reach the target standard to prevent excessive or insufficient grinding. All key data of the grinding process, including the initial position, height, grinding amount and final result of the weld, are recorded to form historical data for easy traceability and quality control.

[0033] In the above embodiment, the present invention replaces traditional manual grinding through the coordinated work of an automated robotic arm and an intelligent weld detection device, thereby greatly improving grinding accuracy and production efficiency. Since the detection and grinding of welds are automated, the amount of each round of grinding can be accurately controlled, avoiding inconsistent standards and quality fluctuations caused by differences in experience in manual grinding. Automated grinding not only increases the grinding speed, but also significantly reduces human errors and the time for repeated corrections, thereby effectively shortening the production cycle. By accurately calculating the amount of each grinding, the consumption of consumables such as grinding discs 3 can be effectively controlled, avoiding excessive consumption, and maintaining a consistent grinding effect for a long time. In addition, the use of automated equipment for grinding operations can effectively reduce the safety risks and labor intensity brought about by manual operations, improve the working environment, reduce employees' exposure to harmful dust and noise, and improve the overall safety and comfort of the production workshop.

[0034] This system is adaptable to complex structural areas, such as taillight corner welds. Through precise robotic arm motion and control of the grinding head (2), it ensures high-precision grinding even in confined, irregularly shaped spaces. This automated weld grinding system is particularly well-suited for the automotive industry, particularly during the welding process of vehicle body-in-white (BIW) production, such as the welding of taillight corner welds. For complex weld structures, the system provides higher grinding accuracy and consistency, helping to improve the automation level and overall production efficiency of the production line.

[0035] The body-in-white weld grinding system provided by this invention utilizes digital and intelligent technologies to address many of the challenges associated with traditional manual grinding. Through automated weld inspection and grinding control, it not only improves production efficiency and product quality, but also enables precise control of consumables and historical data traceability, offering broad application prospects and market value.

[0036] In some embodiments, the weld inspection device includes a contour sensor 5 that emits a linear laser (e.g., a laser beam or line) to acquire laser point cloud data of a target area. The linear laser is irradiated onto the vehicle body surface in the target area. The laser light interacts with the surface and reflects back to the sensor. By precisely measuring the reflection time and angle of the laser light, the sensor acquires laser point cloud data of the surface. This point cloud data represents the spatial coordinates of each surface point, enabling the three-dimensional surface shape of the target area to be reconstructed, thereby identifying and assessing the height, position, and shape of the weld. By comparing the actual weld shape with the target shape (e.g., a standard or preset weld size), the required grinding amount can be accurately calculated.

[0037] In the above-mentioned embodiment, the laser point cloud data has a high spatial resolution, accurately reflecting the shape, size, and irregularities of the weld. For complex geometric shapes on vehicle body surfaces, laser point cloud technology can effectively process and acquire high-precision three-dimensional data, adapting to the diverse needs of weld grinding. Of course, after acquiring the three-dimensional data, the present invention can also simultaneously construct a three-dimensional view, or display a real-time grinding image or a three-dimensional simulation on a display.

[0038] In other embodiments, the weld detection device includes a visual sensor and a distance sensor, which are used to obtain weld detection of the target area through visual recognition. Using the visual sensor, the system can obtain image data of the target area and identify the shape and contour of the weld through image processing techniques (such as edge detection and image segmentation). This can effectively capture information such as the surface characteristics and morphological changes of the weld. The distance sensor provides precise distance data from the surface of the target area. By combining this with the image information from the visual sensor, the system can further obtain three-dimensional information such as the precise position, contour, and height of the weld. By combining the image data provided by the visual sensor with the distance data from the distance sensor, the spatial distribution of the weld can be comprehensively identified, the weld's condition can be further determined (whether there are defects or areas requiring grinding), and the specific grinding amount can be calculated.

[0039] In the above embodiment, the combination of vision and distance sensors can capture information about the target area from multiple dimensions, generating more comprehensive inspection data. The image processing capabilities of the vision sensor can help detect surface defects (such as cracks and pores) in the weld, while the distance sensor ensures accurate measurement of surface geometry and height. This solution can adapt to various weld shapes and structures and is particularly suitable for complex welding areas such as taillight corners and curved surfaces.

[0040] The two aforementioned embodiments utilize laser point cloud technology and vision / range sensor fusion to address weld detection, respectively, each with its own advantages and applicable scenarios. The contour sensor 5, based on laser point cloud technology, possesses high-precision three-dimensional spatial perception and is suitable for regular or relatively simple weld surfaces. The combined vision sensor and range sensor solution, through multi-dimensional information acquisition, is suitable for detecting welds with complex shapes and irregular surfaces. In practical applications, the appropriate solution can be selected based on the specific weld shape, size, and production requirements to achieve the optimal polishing effect. Of course, other sensors and detection methods can also be used to achieve weld detection.

[0041] As at least one feasible approach, the target height of the weld after grinding is determined based on the vehicle body design requirements. For example, the weld area is required to be flush with the vehicle body surface after grinding (with the vehicle body reference surface as the reference, the target height is zero) or maintain a certain predetermined gap. If the weld height is greater than the target height, it is necessary to calculate the amount of grinding to be removed. The calculation formula is: Grinding amount = weld height - target height (if the weld height is greater than the target height); the grinding area is usually calculated by measuring the actual area of ​​the weld area. Assuming that the weld shape is relatively complex, the 3D scanning data can be triangulated to obtain a three-dimensional mesh of the weld surface, and the area is calculated based on the mesh.

[0042] Specifically, the sensor emits a linear laser and obtains the reflected laser point cloud data. Assume that the scanning plane of the sensor is X-Z and the direction of the laser beam is parallel to the Y-axis. For each time t, the sensor obtains point cloud data , where each point Represents a spatial coordinate obtained by laser scanning. is the lateral coordinate corresponding to the scanning position; is the scanning position of the laser (the direction of movement of the sensor), It is the vertical coordinate calculated by the corresponding height, that is, the intensity of the laser reflection, which is generally the distance from the sensor. In order to extract effective information, the original point cloud data needs to be preprocessed, which may include denoising and coordinate transformation. Next, it is necessary to extract the taillight corner surface from the point cloud data and determine the height of the weld. Assume that the taillight corner surface can be represented by a three-dimensional surface fitting. For example, the least squares method can be used to perform surface fitting on the point cloud data to fit the surface model of the taillight corner. On the taillight corner surface, the weld area usually appears as an area with large height changes, and the height of the weld area can be determined by setting a threshold. Based on the height difference of the weld, the amount of grinding of the weld can be calculated. The grinding amount usually refers to the volume of weld material removed. In order to simplify the calculation, it can be approximately considered that the grinding amount is proportional to the height difference of the weld.

[0043] The system in this invention uses weld measurement technology to obtain the actual weld condition in real time and intelligently adjusts the grinding process based on the measurement results. Weld parameters such as thickness, shape, and position all affect the grinding process, and this system effectively guides the grinding operation using measurement data, achieving higher-precision processing. After grinding is completed, the system verifies the grinding results in real time using weld inspection technologies (such as laser scanning and visual inspection) to ensure that the weld surface meets quality standards. If the inspection results deviate, the system automatically adjusts or prompts for manual intervention to ensure the quality of the final product.

[0044] In some embodiments, polishing the taillight corner welds on the body-in-white (BIW) requires polishing at least three surfaces: the weld surface, the body base surface, and the weld transition surface. The weld surface is the surface formed during the welding process and is the surface directly in contact with the weld at the taillight corner. Weld residue, excess solder, protrusions, or pores may be present on the weld surface. This surface polishing requires leveling the weld surface, removing excess solder and burrs, and achieving a smooth, uniform surface to avoid affecting the taillight assembly and body appearance. This surface requires high flatness accuracy, with a surface roughness controllable within Ra0.8-1.6μm to ensure the subsequent painting effect. The body base surface is the body surface in contact with the weld at the taillight corner. During grinding, it is necessary to ensure a smooth transition between the weld and the body's reference surface to avoid unevenness that could affect subsequent assembly. The reference surface must be flat and perpendicular to the other body surfaces, and the weld transition area should be free of noticeable protrusions or depressions to avoid affecting the positioning of the taillights. The flatness and verticality of this surface should be within a reasonable tolerance, for example, within ±0.2mm, to ensure the installation accuracy of the taillight assembly. The weld transition surface is the transition area between the weld area and the surrounding body surface. Grinding this area requires ensuring a natural and smooth transition between the weld joint and the body surface without protrusions. This area requires fine grinding to ensure there are no noticeable step-like changes, and the transition area should be natural and smooth to avoid localized strength loss due to excessive grinding. The transition surface should ensure a smooth transition without protrusions, consistent with the surrounding body surface, and the grinding depth should be controlled within a reasonable range.

[0045] In some embodiments, as Figure 1 As shown, the frame includes a connecting frame 11 and a connecting rod 12. The grinding device is installed on the connecting frame 11, and the connecting frame 11 is installed on the robotic arm through the connecting rod 12. The connecting frame 11 serves as a supporting structure for the grinding device, and the connecting frame 11 plays a bearing role. The main parts of the grinding device (such as the grinding head 2) are installed on the connecting frame 11. The connecting frame 11 enables the grinding device to be connected to other mechanical parts and provides the necessary stability. The connecting rod 12 is used to connect the connecting frame 11 to the robotic arm, plays a fixing role, and ensures the stability of the connection between the grinding device and the robotic arm, thereby ensuring that the grinding device can be accurately positioned and moved during the grinding process. The connecting rod 12 can adopt the connection structure and method of the conventional actuator of the robotic arm in the prior art.

[0046] In some embodiments, as Figure 1As shown, the polishing device also includes a floating force-controlled polishing unit 1, through which the polishing head 2 is mounted on the connecting frame 11. The polishing head 2 also includes a polishing plate 3 at its end. The polishing head 2 is the core component of the polishing device and includes a rotating or vibrating polishing plate 3 that contacts the surface being polished to perform removal, polishing, or trimming operations. The polishing head 2 is mounted on the connecting frame 11 via the floating force-controlled polishing unit 1. The polishing plate 3 is located at the end of the polishing head 2, directly contacting the surface of the body-in-white being polished.

[0047] In the above embodiment, the floating force-controlled grinding unit 1 provides control over the grinding head 2, allowing it to freely adjust within a preset pressure and floating range according to different operating conditions or requirements. This design effectively accommodates varying surface shapes and weld depths, achieving a uniform grinding effect and reducing the risk of damage to the body-in-white surface. The addition of the floating force-controlled grinding unit 1 allows for more precise and flexible operation of the grinding device, enabling it to handle the varying heights and contours of the body-in-white surface, ensuring even pressure distribution during the grinding process and avoiding over-grinding or damage to the body-in-white surface.

[0048] In the above embodiment, the grinding pad 3 is located at the end of the grinding head 2 and is the part that directly contacts the surface being ground. The material and shape of the grinding pad 3 are typically customized based on the surface type being ground (e.g., metal, coating, weld, etc.) and the grinding goal (e.g., removal, polishing, flattening, etc.). The size, hardness, and roughness of the grinding pad 3 will affect the grinding effect.

[0049] In the above-described embodiment, the robotic arm not only achieves wide-range movement and high-precision positioning, but also can control the motion trajectory of the grinding device according to a program, ensuring that the grinding head 2 effectively grinds at different positions and angles. The grinding device in this embodiment of the present invention is connected to the robotic arm via a connecting frame 11 and a connecting rod 12, and is precisely controlled using a floating force-controlled grinding unit 1, enabling fine grinding of welds or other surface areas. The floating force-controlled system is particularly suitable for high-precision grinding operations in automated production environments, can adapt to complex surface shapes, ensure uniform pressure during the grinding process, and improve grinding quality and efficiency.

[0050] In some embodiments, as Figure 1As shown, the weld grinding system also includes a dustproof device, which includes a dustproof cover shell 6, a dustproof cover cover 7, and a cover opening and closing control structure. The weld detection device is installed in a closed box composed of the dustproof cover shell 6 and the dustproof cover cover 7. The weld grinding system in this embodiment of the present invention solves the problem of dust contamination during weld detection and grinding by introducing a dustproof device. Optionally, the dustproof device is installed on the connecting frame 11, located on one side of the grinding device. The purpose of this design is to ensure that the dustproof device can effectively protect the weld detection device and does not interfere with the operation of the grinding device. The dustproof cover shell 6 is connected to the connecting frame 11 by a fixing device, maintaining stability and safety, and ensuring that it will not shift due to vibration or external force during operation. The dustproof cover shell 6 is the basic structure of the entire dustproof device, mainly performing the shell protection and sealing functions, preventing dust or metal particles generated during the weld grinding process from entering the weld detection device, thereby ensuring the normal operation of the equipment. The dust cover plate 7 is located on the dust cover shell 6, and its opening and closing states are adjusted by the opening and closing control structure. Its main function is to prevent dust or metal dust from entering sensitive components according to the different requirements of weld grinding and weld detection.

[0051] In the above embodiment, the cover plate opening and closing control structure is used to control the dust cover plate 7 to remain open when the weld inspection device is inspecting the target area of ​​the body-in-white, allowing the weld inspection device to obtain clear visual or laser point cloud data and accurately perform inspections. It remains closed when the grinding device is grinding welds to prevent metal dust or impurities generated during the grinding process from contaminating the inspection equipment, thereby ensuring that the inspection device is not interfered with by the external environment. The dust cover device automatically switches between weld inspection and grinding operations through the coordinated operation of the dust cover housing 6, the cover plate, and the cover plate opening and closing control structure, ensuring optimal operating environments for both phases, thereby improving the overall efficiency and stability of the system. This design not only improves the level of automation but also ensures a long system life and stable weld grinding quality. Optionally, the cover plate opening and closing control structure can be pneumatic, hydraulic, or electric. For example, the dust cover plate 7 is pneumatically controlled, opening and closing via push-pull translation or hinged flipping.

[0052] In some embodiments, the weld grinding system further includes a passive limiting device, such as Figure 1 As shown, the passive limiter includes a limiter rod 8 and a telescopic mechanism. The end of the limiter rod 8 extends beyond or is flush with the end of the grinding head 2. Its main function is to provide a physical limit to prevent the grinding head 2 from moving excessively when contacting the corresponding area of ​​the body-in-white surface. The passive limiter is installed on the other side of the grinding head 2. Figure 1In the illustrated embodiment, the dustproof device is located on the left side of the grinding device, and the passive limiting device is located on the right side of the grinding device, but is not limited thereto. The passive limiting device can be arbitrarily positioned according to actual needs.

[0053] In the above embodiment, the telescopic mechanism is used to adjust the limiting distance of the limiting rod 8 so that it can flexibly adjust the contact point with the body-in-white surface as needed. When the end of the limiting rod 8 contacts the body-in-white surface, or moves backward for a safety margin, the grinding device is configured so that the grinding head 2 stops rotating or the grinding head 2 is controlled by the robotic arm to move in a direction away from the body-in-white. When contacting the surface, the limiting rod 8 plays a limiting role, preventing the grinding head 2 from continuing to contact the body-in-white surface in depth, thereby avoiding damage to the body-in-white or excessive grinding. The telescopic mechanism can accurately adjust the length of the limiting rod 8 so as to provide appropriate limiting effects in different weld areas or different grinding requirements to prevent the grinding head 2 from causing damage to the body-in-white. The advantage of this design is that the limiting device is passively controlled, that is, the limiting rod 8 will automatically contact the surface and limit it without excessive external intervention, providing a more automated and stable operation process.

[0054] As at least one achievable method, Figure 1 As shown, the telescopic mechanism includes an electric cylinder 9 and a linear motor 10, that is, the setting and adjustment of the limit distance of the telescopic mechanism are achieved by electronic control; but it is not limited to this, and this function can also be achieved by using a pneumatic, hydraulic or mechanical linear motion mechanism. The introduction of a passive limit device reduces manual intervention and improves the level of automation. The operator does not need to intervene too much in each grinding operation, but only needs to set the appropriate limit distance, and the system will automatically adjust it. The passive limit device is particularly suitable for grinding the welds of the body-in-white, because the surface of the body-in-white may have different weld shapes and depths. By flexibly adjusting the limit rod 8, the grinding device can perform appropriate grinding treatment for different weld conditions without causing excessive grinding or damage to the workpiece.

[0055] In some embodiments, the weld grinding system also includes an active limiter unit, which is used to limit the movement trajectory of the robotic arm based on the shortest distance between the grinding head 2 and the body-in-white surface. During the grinding process, the system dynamically adjusts the movement of the robotic arm based on real-time distance data feedback, ensuring that the grinding head 2 performs its task within the appropriate distance range. As at least one implementation method, the active limiter unit can be integrated with a distance sensor or laser rangefinder to monitor the shortest distance between the grinding head 2 and the body-in-white in real time. Based on this distance information, the system determines whether to adjust the robotic arm's movement path to prevent the grinding head 2 from getting too close to the body-in-white, causing damage or excessive grinding. Because the system can obtain real-time distance data between the grinding head 2 and the body surface, it can dynamically adjust the robotic arm's trajectory based on different grinding conditions (such as weld depth, body curvature, etc.), ensuring the efficiency and accuracy of the grinding process.

[0056] The active limiter in this embodiment of the present invention precisely limits the movement trajectory of the robotic arm by monitoring the minimum distance between the grinding head 2 and the body-in-white surface in real time, ensuring safety, accuracy, and efficiency during the grinding process. By automatically adjusting the distance between the grinding head 2 and the body surface, excessive grinding or mechanical collisions are avoided, enhancing the intelligence and stability of the automated grinding system. It is suitable for body-in-white weld grinding and other industrial applications requiring high-precision control. On large-scale body-in-white production lines, the active limiter can provide consistent grinding quality while improving production efficiency and adapting to the weld grinding needs of different batches or products.

[0057] In some embodiments, the weld grinding system further includes a tool changer, which is configured to be equipped with at least one new grinding head 2 or grinding disc 3. When the grinding disc 3 of the grinding head 2 is worn out and can no longer complete the grinding task, the robot arm controls the grinding head 2 to move to a tool change position and automatically replace it with a new grinding head 2 or grinding disc 3. Each grinding head 2 is bonded to a grinding disc 3, which gradually wears out during the grinding process. When the grinding disc 3 is worn out and can no longer complete the task, the system triggers a tool change via a pre-set control program.

[0058] As at least one possible implementation, the device includes a fixture with a specific structure. The fixture is used to hold a new grinding head 2 or grinding disc 3 and to separate and connect it to the floating force-controlled grinding unit 1 through axial pressure. A robotic arm is responsible for moving the grinding head 2 to the tool-changing position. The robot uses a motion trajectory to guide the grinding head 2 to the tool-changing position. When the grinding head 2 enters the fixture in the tool-changing mechanism, the fixture applies axial pressure, forcing the grinding head 2 to separate from the floating force-controlled grinding unit 1. At this point, the old grinding head 2 is no longer connected to the grinding unit. The robot trajectory continues to move to the position of the new grinding head 2. The new grinding head 2 gradually enters the fixture, and the fixture also applies axial pressure to help the new grinding head 2 smoothly dock with the floating force-controlled grinding unit 1, completing the replacement of the grinding head 2. The replaced grinding head 2 and used grinding disc 3 are handled by a human operator, who removes the grinding disc 3, installs a new one, and then returns the grinding head 2 to the tool-changing area, awaiting its next use. The connection between the grinding head 2 and the grinding disc 3 is designed to be removable (e.g., adhesively bonded) for easy periodic replacement. The grinding head 2 can be connected to the floating force-controlled grinding unit 1 via a quick-connect mechanism 4 or an electromagnetic connection mechanism. Quick-connect mechanism 4 includes, but is not limited to, keyways, threads, and snap-fit ​​connections. This connection structure can employ conventional methods used in CNC machine tools or industrial robots.

[0059] In the above embodiment, through the cooperation of the robotic arm and the tool changing device, the replacement of the grinding head 2 and the grinding sheet 3 is fully automated, which reduces manual intervention and improves production efficiency. The tool changing device can significantly reduce downtime. After the grinding head 2 and the grinding sheet 3 are consumed, there is no need to wait for manual replacement, ensuring the continuous operation of the production line. The automatic tool changing operation reduces the workload of the operator and can avoid production delays caused by untimely manual replacement. Since the grinding head 2 is always maintained in a suitable working state, excessive consumption is avoided, and the service life of the grinding device can be effectively extended. The tool changing process is precisely controlled by the robotic arm, which avoids errors in human operation and ensures the continuity and consistency of the grinding process.

[0060] In other embodiments, the automatic replacement target is not the entire grinding head 2, but rather the grinding disc 3. This method has the advantage of replacing only the worn grinding disc 3, saving the cost and time of replacing the entire grinding head 2 and maximizing the lifespan of the grinding head 2. The grinding disc 3 can be connected to the grinding head 2 via a snap, magnet, or latch. The automated system, controlled by precise robotic arms, automatically removes the worn grinding disc 3 and installs a new one when the grinding disc 3 becomes worn. This approach reduces the complexity of the tool change process, allowing quick resumption of work by simply replacing the grinding disc 3.

[0061] In some embodiments, the weld grinding system further includes a data storage module. Optionally, the data storage module is used to store and record the vehicle number of each BIW, weld inspection results, and weld grinding results. The data storage module is also used to record the consumption and inventory of the grinding head 2. This data storage module not only helps track and manage key information during the weld grinding process, but also optimizes production processes, improving efficiency and quality control.

[0062] Each body-in-white (BIW) typically has a unique vehicle number (such as a vehicle serial number or identification code). During the grinding process, the data storage module records the weld inspection and grinding results associated with each BIW, ensuring traceability to the specific vehicle. This allows for quick retrieval and location of all data associated with that vehicle number during quality tracking or when issues arise. This ensures that each BIW weld is properly inspected and polished to meet quality standards. Weld grinding results record the actual grinding status of each weld, including grinding time, grinding depth, grinding tools used, and their efficiency. This data helps ensure that weld grinding meets standard requirements, avoiding quality issues caused by insufficient or non-standard grinding. It also helps optimize production line workflows, analyze grinding process efficiency, and identify potential bottlenecks. Recording grinding head consumption and inventory levels is a key management function, ensuring an adequate supply of grinding heads throughout the production process and enabling timely replacement.

[0063] In the above embodiment, the data storage module serves more than just a recording tool; it also interfaces with other system components (such as the weld inspection device and grinding device) in real time to dynamically update relevant data. This real-time feedback allows the weld grinding system to automatically adjust grinding parameters (such as grinding pressure and speed) to ensure optimal results. It also proactively detects potential problems. For example, upon detecting a weld defect, the system can promptly issue an alarm and pause grinding. This accumulated data can be used not only to optimize the grinding process for individual products but also to support overall production line optimization. As data accumulates, the data storage module can also support data analysis. The system can generate predictions based on historical data, such as the replacement cycle for the grinding head 2, inventory requirements, and equipment maintenance cycles. When combined with a visual interface, the data storage module provides production personnel with real-time operational feedback and statistical data. Through charts and reports, production personnel can quickly understand key indicators during the grinding process, such as grinding head 2 consumption, grinding progress for each vehicle, and weld quality, facilitating subsequent quality traceability, process improvement, and production analysis.

[0064] In a second aspect, the present invention also provides a body-in-white weld grinding method, which is implemented based on the aforementioned weld grinding system. The implementation of this weld grinding method relies on a systematic process, combining a weld detection device, a grinding device, and target height management to ensure that the height of each weld meets the predetermined standard. This method ensures the accuracy and efficiency of weld grinding through real-time detection and adjustment. Figure 2 As shown, the method includes:

[0065] S10. The weld detection device detects the body reference surface and the weld to be polished in the target area of ​​the body-in-white (BIW) to determine the position and height of the weld to be polished. In this step, the weld detection device may utilize a laser profile sensor 5, a 3D scanner, or other measuring tool. The body reference surface is the designed surface or flat area of ​​the body used for comparison with the weld position. The weld area to be polished is identified, including its position and height information. For example, laser scanning or other techniques are used to obtain point cloud data of the body surface and extract the weld location. The height of the weld area (the height difference from the reference surface) can be determined using height data or a surface fitting algorithm.

[0066] S20: Determine the grinding amount of the weld based on the height of the weld to be ground and the target height. In this step, a calculation based on the height difference is used to determine the specific height difference to be ground. The actual grinding amount (e.g., the volume of material removed) can be estimated by using modeling of some grinding devices, combined with the shape and efficiency of the grinding tool.

[0067] S30: Based on the location of the weld to be ground and the grinding amount, control the grinding device to perform an initial grinding of the weld to be ground. In this step, the grinding device's path is planned based on the weld's location to ensure that the device accurately reaches the weld area. The grinding depth is controlled based on the previously calculated height difference.

[0068] S40. After the initial grinding of the weld to be polished is completed, the weld is inspected using the weld inspection device. If the actual height of the weld is still greater than the target height, the grinding device is controlled to continue grinding until the weld reaches the target height. In this step, if the height difference still exists, the grinding device is controlled to continue grinding until the target height is reached. This process may be repeated multiple times until the weld height reaches the preset target.

[0069] In the above-described embodiment, precise detection and real-time feedback ensure that the weld height reaches the desired target, avoiding over- or under-grinding. Combined with automated grinding equipment and sensor detection, this significantly improves production efficiency and reduces human error. Real-time detection and adjustment during the grinding process ensure accurate grinding results and adaptability to varying weld shapes and height requirements. This method is suitable for weld finishing in automotive manufacturing, particularly body-in-white production lines, improving weld quality and consistency while optimizing production efficiency.

[0070] In some embodiments, the method further includes: during the grinding process of the grinding device, the depth of the grinding head 2 is controlled by the passive limit device, and if the end of the limit rod 8 contacts the surface of the body-in-white, the grinding head 2 is controlled to stop rotating or the grinding head 2 is controlled by the robotic arm to move in a direction away from the body-in-white. In this embodiment, the passive limit device triggers a control signal through physical contact, so that the grinding head 2 can automatically adjust its action (stop or move) according to the contact situation; through the design of the passive limit device, the working depth of the grinding head 2 is automatically controlled to avoid excessively deep or shallow grinding caused by human errors. This method is to trigger a control signal through physical contact of the passive limit device, so that the grinding head 2 can automatically adjust its action (stop or move) according to the contact situation, without the need for complex sensors or height detection systems, and directly achieve control of the depth of the grinding head 2 through passive limiting.

[0071] In some embodiments, the method further includes: during the grinding process of the grinding device, by detecting the shortest distance between the grinding head 2 and the surface of the white body, the active limiting unit limits the movement trajectory of the robotic arm. In this embodiment, the range of motion of the robotic arm is limited by the control of the active limiting unit, thereby preventing the grinding head 2 from getting too close to the body surface and reducing accidental damage to the body. This method can accurately control the distance during the grinding process through real-time detection and adjustment, avoiding close contact or uneven grinding; preventing the robotic arm from getting too close to the body, reducing the risk of damage caused by improper operation; and can adapt to the surface shapes of different body parts, ensuring stable grinding even on complex surfaces.

[0072] In the above embodiment, the passive limiter directly controls the depth of the grinding head 2 through physical contact, reducing damage caused by over-grinding or misoperation. The active limiter precisely controls the movement trajectory of the robotic arm by real-time monitoring of the distance between the grinding head 2 and the vehicle body surface, thereby optimizing the accuracy and safety of the grinding process. The combined use of the passive and active limiters provides redundant protection and increases reliability. If one system malfunctions or fails, the other can continue to operate, ensuring the safe progress of the grinding process. For example, if the active limiter fails due to a sensor malfunction, the passive limiter can still provide mechanical contact to prevent the grinding head 2 from entering too deeply. By combining these two systems based on different principles, the reliability and fault tolerance of the overall system are significantly improved. In actual applications, the vehicle body surface may undergo subtle variations due to differences in shape, material, or coating. Relying on a single approach (e.g., passive limiters or active limiters alone) may not be sufficient to address all complex situations. Passive limiters provide effective depth control with fast response and a simple environment, while active limiters continuously acquire data, adapt to changes, and adjust working strategies in real time. Used in combination, the system maintains efficient sanding results under varying working conditions and surface shapes, providing both basic protection and precise control.

[0073] The weld grinding system and method in the embodiments of the present invention can be applied to complex environments and achieve high-precision, high-quality weld grinding. It is not only applicable to the corner welds of the taillights of the white body, but also to any welds in the white body of the automobile that can be reached by the grinding device. Whether it is a small space or a weld position that is difficult to reach manually, the present invention can provide an effective grinding solution.

[0074] The weld grinding system and method in the embodiments of the present invention can operate stably in a variety of complex environments and adapt to different production conditions and working conditions, such as welds of different shapes and materials produced after car body welding. The present invention ensures high precision and high quality of the weld grinding process through advanced grinding technology and intelligent control, and can effectively remove excess materials produced during the welding process, such as welding spatter and residual weld marks, to ensure that the weld surface is smooth and meets quality standards. The present invention can quickly and efficiently complete the weld grinding task, reduce manual intervention, improve the degree of automation of the production line, realize online grinding of the production line, and thus improve overall production efficiency. The present invention combines modern numerical control technology and robotics technology, and can automatically adjust the grinding parameters to adapt to the grinding requirements of different welds, ensuring that each grinding can achieve the best effect. The weld grinding system and method in the embodiments of the present invention not only excel in high precision and high quality, but also have strong adaptability and efficiency, and can meet the diverse needs for weld grinding in the modern automobile manufacturing process.

[0075] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When executed by a processor, the computer program implements the steps of the aforementioned weld grinding method. The computer-readable storage medium can be a tangible storage medium, such as a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, floppy disk, hard disk, removable storage disk, CD-ROM, or any other form of storage medium known in the art.

[0076] It should be understood by those skilled in the art that the various exemplary components, systems, and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether to implement the system in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via a data signal carried in a carrier wave.

[0077] It should be understood that the present invention is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted. In the above embodiments, several specific steps are described and illustrated as examples. However, the method of the present invention is not limited to the specific steps described and illustrated. Those skilled in the art may make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present invention.

[0078] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or replace features of other embodiments.

[0079] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations to the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A body-in-white weld grinding system, characterized in that: The weld grinding system comprises: a frame, a grinding device and a weld detection device installed on the frame; The weld detection device is used to detect the body reference surface and the weld to be polished in the target area of ​​the body in white to obtain the position and height of the weld to be polished; and is also used to obtain the polishing amount of the weld based on the height of the weld to be polished and the target height; The grinding device comprises a mechanical arm and a grinding head (2), wherein the grinding head (2) is mounted on the mechanical arm, and the grinding device is used to perform initial grinding on the weld to be ground based on the position of the weld to be ground and the grinding amount; The weld detection device is also used to detect the weld to be polished after the initial polishing is completed, until the weld to be polished reaches a target height.

2. The body-in-white weld grinding system according to claim 1, characterized in that: The weld detection device comprises a contour sensor (5), wherein the contour sensor (5) is capable of emitting linear laser light to obtain laser point cloud data of a target area; or, The weld detection device includes a visual sensor and a distance sensor, which are used to obtain weld detection of a target area by visual recognition.

3. The body-in-white weld grinding system according to claim 1, characterized in that: The frame comprises a connecting frame (11) and a connecting rod (12); the polishing device is mounted on the connecting frame (11); and the connecting frame (11) is mounted on the mechanical arm via the connecting rod (12); The grinding device further comprises a floating force-controlled grinding unit (1), the grinding head (2) is mounted on the connecting frame (11) via the floating force-controlled grinding unit (1), and the grinding head (2) further comprises a grinding sheet (3) located at the end thereof.

4. The body-in-white weld grinding system according to claim 3, characterized in that: The weld grinding system further comprises a dustproof device, the dustproof device comprising a dust cover shell (6), a dust cover cover plate (7) and a cover plate opening and closing control structure, and the weld detection device is installed in a closed box body composed of the dust cover shell (6) and the dust cover cover plate (7); The cover opening and closing control structure is used to control the dust cover (7) to remain in an open state when the weld detection device is detecting the target area of ​​the body-in-white, and to remain closed when the grinding device is grinding the weld; The dustproof device is mounted on the connecting frame (11) and is located on one side of the grinding device.

5. The body-in-white weld grinding system according to claim 3, characterized in that: The weld grinding system further comprises a passive limiting device, the passive limiting device comprising a limiting rod (8) and a telescopic mechanism, the end of the limiting rod (8) exceeds the end of the grinding head (2) or is flush with the end of the grinding head (2); the passive limiting device is installed on the other side of the grinding head (2); The telescopic mechanism is used to adjust the limiting distance of the limiting rod (8); when the end of the limiting rod (8) contacts the surface of the body-in-white, the grinding device is configured so that the grinding head (2) stops rotating or the mechanical arm controls the grinding head (2) to move in a direction away from the body-in-white.

6. The body-in-white weld grinding system according to claim 5, characterized in that: The weld grinding system further comprises an active limiting unit, which is used to limit the movement trajectory of the robot arm through the shortest distance from the grinding head (2) to the surface of the body-in-white.

7. The body-in-white weld grinding system according to claim 5, characterized in that: The weld grinding system further comprises a tool changing device, wherein the tool changing device is used to install at least a new grinding head (2) or a grinding sheet (3); The tool changing device is used to control the grinding head (2) to move to a tool changing position by the mechanical arm when the grinding sheet (3) of the grinding head (2) is consumed to the point where the grinding work cannot be completed, and automatically replace the grinding head (2) or grinding sheet (3) with a new one.

8. The body-in-white weld grinding system according to claim 5, characterized in that: The weld grinding system also includes a data storage module; The data storage module is used to store and record the vehicle number, weld inspection results and weld grinding results of each body-in-white, wherein the weld grinding results include over-grinding; The data storage module is also used to record the consumption and inventory of the grinding head (2).

9. A method for grinding a body-in-white weld, characterized in that: The method is implemented based on the weld grinding system according to any one of claims 1 to 8, and the method comprises: Detecting the body reference surface and the weld to be polished in the target area of ​​the body-in-white by the weld detection device to obtain the position and height of the weld to be polished; Obtaining a grinding amount of the weld based on the height of the weld to be ground and a target height; Based on the position of the weld to be polished and the polishing amount, controlling the polishing device to perform initial polishing on the weld to be polished; After the initial grinding of the weld to be ground is completed, the weld is then tested using the weld detection device; if the actual height of the weld is still greater than the target height, the grinding device is controlled to continue grinding it until the weld to be ground reaches the target height.

10. The weld grinding method according to claim 9, characterized in that: The method further comprises: During the grinding process of the grinding device, the depth of the grinding head (2) is controlled by a passive limit device, and if the end of the limit rod (8) contacts the surface of the body-in-white, the grinding head (2) is controlled to stop rotating or the mechanical arm controls the grinding head (2) to move in a direction away from the body-in-white; and / or, During the grinding process of the grinding device, the moving track of the mechanical arm is limited by the active limit unit by detecting the shortest distance from the grinding head (2) to the surface of the body-in-white.

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