Weld joint grinding method and weld joint grinding system for workpiece

Abstract

The invention discloses a weld joint grinding method and system for a workpiece. A lug plate is welded to a workpiece, an actual welding seam is formed between the end face of the lug plate and the workpiece, the actual to-be-polished face of the actual welding seam is formed by the surface, away from the workpiece, of the welding seam, and the workpiece welding seam polishing method comprises the following steps that size parameters of the lug plate are obtained, and the curvature radius of the arc-shaped polishing face of the polishing device is determined according to the size parameters; acquiring a starting point coordinate, a starting point posture, an end point coordinate and an end point posture of the polishing device moving along the actual to-be-polished surface; and according to the starting point coordinates, the starting point posture, the end point coordinates and the end point posture, the moving track of the grinding device is obtained, and the grinding device is controlled to move for grinding according to the moving track. The matched arc-shaped grinding face is determined according to the size of the lug plate, so that the curvature radius of the arc-shaped grinding face is appropriate, smooth grinding of the surface of the weld joint can be effectively achieved in combination with planning of the moving track, and the grinding quality is improved.

Description

Technical Field

[0001] The present application relates to the technical field of weld grinding, and in particular to a weld grinding method and a weld grinding system for a workpiece. Background Art

[0002] In the production process of large equipment such as construction machinery excavators and mining digger booms, the grinding process is an indispensable link. The welding and grinding of structural parts currently relies mainly on manual operation. Workers hold grinding tools and carefully grind each part of the structural parts. However, this method has many problems. First, the efficiency of manual grinding is low, especially for some large structural parts. The grinding workload is very large and time-consuming. Second, due to the experience and technical level of workers, the quality of manual grinding is unstable, and the same batch of products may have inconsistent quality.

[0003] It should be noted that the statements in this background technology section only provide background technology related to the present application and do not necessarily constitute prior art. Summary of the invention

[0004] The present application provides a weld seam grinding method and a weld seam grinding system for a workpiece to improve the grinding quality.

[0005] In a first aspect, the present application provides a method for grinding a weld of a workpiece, wherein an ear plate is welded on the workpiece. The ear plate is placed upright on the workpiece, and the ear plate includes a bottom surface in contact with the surface of the workpiece and an end surface arranged at the end of the bottom surface. An actual weld is formed between the end surface of the ear plate and the workpiece. The actual weld extends from the end surface of the ear plate along the length direction of the ear plate to the surface of the workpiece. The actual surface to be ground of the actual weld is formed by the surface of the weld away from the workpiece. The weld grinding method is used to grind the actual weld. The weld grinding method includes the following steps:

[0006] Obtaining the size parameters of the ear plate and determining the curvature radius of the arc-shaped grinding surface of the grinding device according to the size parameters;

[0007] Obtaining the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device moving along the actual surface to be ground; and

[0008] The moving trajectory of the grinding device is acquired according to the starting point coordinates, the starting point posture, the ending point coordinates and the ending point posture, and the grinding device is controlled to move according to the moving trajectory to perform grinding.

[0009] In some embodiments, determining the curvature radius of the arc-shaped grinding surface of the grinding device according to the size parameters includes: calculating and obtaining a theoretical surface to be grinded according to the size parameters, and determining the curvature radius of the arc-shaped grinding surface according to the theoretical surface to be grinded.

[0010] In some embodiments, determining the curvature radius of the curved grinding surface of the grinding device according to the theoretical surface to be polished includes: the curvature radius of the curved grinding surface is constructed so that the curved grinding surface is tangent to both the theoretical surface to be polished and the surface of the workpiece, and the tangent line between the curved grinding surface and the surface of the workpiece is located on the side of the actual surface to be polished close to the ear plate.

[0011] In some embodiments, a plurality of ear plates are welded on the workpiece, and determining the curvature radius of the arc-shaped grinding surface of the grinding device according to the theoretical surface to be grinded includes: determining a plurality of curvature radii of the plurality of arc-shaped grinding surfaces according to a plurality of size parameters of the plurality of ear plates, respectively, and taking the minimum value of the plurality of curvature radii as the curvature radius of the arc-shaped grinding surface of the grinding device.

[0012] In some embodiments, the weld grinding method further includes: obtaining the weld width of the actual weld in the thickness direction of the ear plate, and the size of the arc-shaped grinding surface in the thickness direction of the ear plate is greater than or equal to the weld width.

[0013] In some embodiments, obtaining the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device moving along the actual surface to be grinded includes: obtaining the starting point coordinates and starting point posture based on point cloud data processing technology.

[0014] In some embodiments, obtaining the starting coordinates, starting posture, end point coordinates and end point posture of the grinding device moving along the actual surface to be grinded includes: obtaining the end point coordinates and end point posture based on point cloud data processing technology, and the end point posture is configured so that, in a projection plane perpendicular to the thickness direction of the ear plate, at the end point coordinates, a line connecting the contact point between the arc-shaped grinding surface and the actual weld and the center of the curvature circle of the arc-shaped grinding surface is perpendicular to the surface of the workpiece.

[0015] In some embodiments, the moving trajectory of the grinding device is obtained according to the starting point coordinates, the starting point posture, the ending point coordinates and the ending point posture, and the grinding device is controlled to move for grinding according to the moving trajectory, including: calculating multiple trajectory points in the process of the grinding device moving from the starting point coordinates to the ending point coordinates based on the interpolation principle, and controlling the grinding device to move along the multiple trajectory points in sequence for grinding.

[0016] The second aspect of the present application provides a weld grinding system, wherein a lug plate is welded on a workpiece. The lug plate is vertically placed on the workpiece, and the lug plate includes a bottom surface in contact with the surface of the workpiece and an end surface arranged at the end of the bottom surface. An actual weld is formed between the end surface of the lug plate and the workpiece. The actual weld extends from the end surface of the lug plate to the surface of the workpiece along the length direction of the lug plate. The actual surface to be ground of the actual weld is formed by the surface of the weld away from the workpiece. The radius of curvature of the arc-shaped grinding surface of the grinding device is determined according to the size parameters of the lug plate. The grinding device is mounted on a robotic arm. The robotic arm is used to drive the grinding device to move to grind the actual weld. The control module is used to obtain the starting coordinates, starting posture, end coordinates and end posture of the grinding device moving along the actual surface to be ground, and obtain a moving trajectory according to the starting coordinates, starting posture, end coordinates and end posture to control the movement of the robotic arm so that the grinding device moves according to the moving trajectory for grinding.

[0017] In some embodiments, the actual weld has a theoretical surface to be ground that is related to the size parameters of the ear plate, and the radius of curvature of the arc-shaped ground surface is determined by the theoretical surface to be ground.

[0018] In some embodiments, the curvature radius of the arcuate grinding surface is configured to make the arcuate grinding surface tangent to both the theoretical surface to be grinded and the surface of the workpiece, and the tangent line between the arcuate grinding surface and the surface of the workpiece is located on the side of the actual surface to be grinded close to the ear plate.

[0019] In some embodiments, the control module is configured to control the movement of the robot arm to perform grinding according to the weld grinding method described above.

[0020] In some embodiments, the weld grinding system also includes a force control device, which is arranged at the end of the robotic arm. The grinding device is drivingly connected to the force control device. The force control device is configured to control the grinding device to float up and down to stabilize the grinding force according to the concave and convex conditions of the surface to be polished during the movement of the grinding device along the surface to be polished.

[0021] In some embodiments, the grinding device includes a grinding wheel or a grinding belt.

[0022] Based on the technical solution provided in the present application, an ear plate is welded on the workpiece, the ear plate is vertically placed on the workpiece, and the ear plate includes a bottom surface in contact with the surface of the workpiece and an end surface arranged at the end of the bottom surface, an actual weld is formed between the end surface of the ear plate and the workpiece, the actual weld extends from the end surface of the ear plate along the length direction of the ear plate to the surface of the workpiece, the actual surface to be polished of the actual weld is formed by the surface of the weld away from the workpiece, and the weld polishing method is used to polish the actual weld, and the weld polishing method of the workpiece includes the following steps: obtaining the size parameters of the ear plate and determining the curvature radius of the arc-shaped polishing surface of the polishing device according to the size parameters; obtaining the starting point coordinates, starting point posture, end point coordinates and end point posture of the polishing device moving along the actual surface to be polished; and obtaining the moving trajectory of the polishing device according to the starting point coordinates, starting point posture, end point coordinates and end point posture, and controlling the movement of the polishing device according to the moving trajectory for polishing. The arc-shaped grinding surface is determined according to the size of the ear plate, so that the radius of curvature of the arc-shaped grinding surface is appropriate. Combined with the planning of the moving trajectory, the weld surface can be effectively polished smoothly, reducing damage to the area near the junction of the weld and the base material, achieving a smooth transition, and reducing the need for manual trimming after automatic grinding, thereby improving the grinding quality.

[0023] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0025] Figure 1 This is a schematic diagram of a weld grinding system according to some embodiments of the present application grinding a weld on a workpiece A.

[0026] Figure 2 for Figure 1 Schematic diagram of the end of the robotic arm.

[0027] Figure 3 This is a schematic diagram of a grinding device according to some embodiments of the present application grinding a weld.

[0028] Figure 4 This is a schematic diagram of an actual weld formed by welding an ear plate and a workpiece in some embodiments of the present application.

[0029] Figure 5 for Figure 4 A partial enlarged view of the actual weld.

[0030] Figure 6 Schematic diagram of grinding welds using grinding devices with three different curvature radii.

[0031] Figure 7 It is a diagram of the intermediate states of the arc-shaped grinding surface of the grinding device at different positions during the grinding process.

[0032] Figure 8 This is a schematic diagram of the surface position of a weld after the weld is ground according to the weld grinding method provided in some embodiments of the present application. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0035] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, and the spatially relative descriptions used here are interpreted accordingly.

[0036] In recent years, automatic grinding technology has gradually emerged and has been applied to a certain extent in the field of engineering machinery manufacturing. Compared with traditional manual grinding, flexible grinding robots have significant advantages. Flexible grinding robots can greatly improve grinding efficiency. The robot can work continuously for a long time without being affected by fatigue, which significantly shortens the production cycle; the grinding quality is significantly improved. Through precise control algorithms, the robot can achieve uniform and stable grinding effects and reduce quality fluctuations caused by human factors.

[0037] Although flexible grinding robots can achieve efficient and accurate automatic grinding in most areas, they still face many challenges when dealing with some parts with complex shapes. Taking the dovetail part of the excavator arm and boom (i.e. the weld at the welding connection between the ear plate and the arm and boom) as an example, the grinding of the dovetail part is difficult for the robot to fully handle due to its special shape and complex grinding path. Specifically, the grinding of the dovetail part needs to be carried out in a narrow space, and the transition position between the base material and the weld needs to achieve a smooth transition to reduce damage to the base material of the workpiece. At the same time, the grinding angle and force must be precise. This places extremely high demands on the robot's sensor accuracy, the complexity of the control algorithm, and the flexibility of the actuator.

[0038] After research, the inventors of the present application found that, at present, the surface quality of the dovetail part after automated grinding by the flexible grinding robot has not yet reached an ideal state. Usually, after the initial grinding by the robot, the surface of the dovetail part still needs to be manually repaired and ground to ensure a smooth transition as much as possible and to meet the requirements of not damaging the parent material. This not only increases production costs, but also to a certain extent offsets the efficiency improvement brought about by the automatic grinding technology.

[0039] In view of the above problems, some embodiments of the present application provide a weld grinding method for a workpiece, which is used to grind an actual weld W weld, wherein the weld grinding method comprises the following steps:

[0040] Obtaining the size parameters of the ear plate B and determining the curvature radius of the arc-shaped grinding surface of the grinding device 2 according to the size parameters;

[0041] Obtaining the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device 2 moving along the actual surface to be grinded; and

[0042] The moving track of the grinding device 2 is acquired according to the starting point coordinates, the starting point posture, the ending point coordinates and the ending point posture, and the grinding device 2 is controlled to move for grinding according to the moving track.

[0043] First, the welding connection relationship between the ear plate B and the workpiece A (the workpiece A includes, for example, a boom or a movable arm) is described.

[0044] refer to Figures 3 to 5, the ear plate B is placed upright on the workpiece A, and the ear plate B includes a bottom surface in contact with the surface of the workpiece A and an end surface arranged at the end of the bottom surface. An actual weld W is formed between the end surface of the ear plate B and the workpiece A. The actual weld W extends from the end surface of the ear plate B along the length direction X of the ear plate B to the surface of the workpiece A. The actual surface to be polished of the actual weld W is formed by the surface of the weld W away from the workpiece A. In other words, the actual weld W is located at the end of the length direction X of the ear plate B, and both ends of the ear plate B along the length direction X can be connected to the workpiece A by welding, and the polishing of the welds located at both ends of the ear plate in the length direction X is applicable to the weld polishing method provided in the embodiment of the present application.

[0045] The arc-shaped grinding surface is determined to match the size of the ear plate B, so that the radius of curvature of the arc-shaped grinding surface is appropriate. Combined with the planning of the moving trajectory, the weld surface can be effectively polished smoothly, reducing damage to the area near the junction of the weld and the base material, achieving a smooth transition, and reducing the need for manual trimming after automatic grinding, thereby improving the grinding quality.

[0046] In some embodiments, determining the curvature radius of the arc-shaped grinding surface of the grinding device 2 according to the size parameters includes: calculating and obtaining a theoretical surface to be grinded according to the size parameters, and determining the curvature radius of the arc-shaped grinding surface according to the theoretical surface to be grinded.

[0047] Figure 5 Shown for Figure 4 The actual weld W in the partial enlarged view, and the projection of the actual weld W in the thickness direction Y perpendicular to the ear plate B is shown below. Figure 5 The definition of the actual weld W and the theoretical surface to be ground is explained in detail.

[0048] Based on the size parameters of the ear plate B (i.e., the end face height of the ear plate B), there is a theoretical weld length (also called the target weld length, which is a numerical value relative to the end face height of the ear plate B obtained based on experience). The theoretical weld length is defined as the theoretical length or expected length of the weld extending relative to the end face of the ear plate B in the length direction X. The point on the workpiece surface corresponding to the theoretical length is the theoretical point T1, the high point of the end face of the ear plate B is P1, the low point is P2, and the line connecting the high point P1 and the theoretical point T1 is the theoretical position of the surface to be polished L1. However, after welding, the extension length of the weld will be slightly longer than the theoretical length, that is, the intersection of the actual weld W and the surface of the workpiece A is the actual point T2, and the line connecting the high point P1 and the actual point T2 is the actual position of the surface to be polished L2. The area formed by the lines connecting the high point P1, the low point P2 and the theoretical point T1 is the theoretical weld, and the area formed by the lines connecting the high point P1, the low point P2 and the theoretical point T2 is the actual weld W. The excess area of ​​the actual weld relative to the theoretical weld will be ground away by the grinding device 2.

[0049] Following the above analysis, if the radius of curvature is selected to be larger, the arc-shaped grinding surface will be ground to the theoretical position of the surface to be ground L1 during the grinding process, thus affecting the integrity of the weld. After calculating the theoretical position of the surface to be ground L1, the curvature radius of the arc-shaped grinding surface of appropriate size can be determined, so that the arc-shaped grinding surface will not cause damage to the theoretical surface to be ground during the grinding process, ensuring the stability of the welding connection between the ear plate B and the workpiece A and improving the grinding quality.

[0050] In some embodiments, determining the curvature radius of the arc-shaped grinding surface of the grinding device 2 according to the theoretical surface to be polished includes: the curvature radius of the arc-shaped grinding surface is constructed so that the arc-shaped grinding surface is tangent to both the theoretical surface to be polished and the surface of the workpiece A, and the tangent line between the arc-shaped grinding surface and the surface of the workpiece A is located on the side of the actual surface to be polished close to the ear plate B.

[0051] Specifically, continue to refer to Figure 5 , Figure 5 The diagram shows that three arcs of different sizes are tangent to the theoretical surface to be polished and the surface of the workpiece A. The curvature radii of the three arcs are arranged from large to small as the third arc R3, the second arc R2 and the first arc R1. The tangent points of the three arcs to the surface of the workpiece A are the third tangent point K3, the second tangent point K2 and the first tangent point K1. The first tangent point K1 is located on the side of the actual point T2 close to the ear plate B, and the third tangent point K3 and the second tangent point K2 are located on the side of the actual point T2 away from the ear plate B.

[0052] If the curvature radius of the arc-shaped grinding surface of the grinding device 2 is selected as the curvature radius of the second arc R2 or the third arc R3, then when the arc-shaped grinding surface is tangent to the theoretical surface to be polished L1, another position on it and the surface of the workpiece A are tangent to the outside of the actual point T2, indicating that in the process of the grinding device 2 moving from the high point P1 to the end of the weld, the weld near the actual point T2 cannot be polished without polishing the theoretical surface to be polished, thus resulting in a poor grinding effect. If the curvature radius of the arc-shaped grinding surface of the grinding device 2 is selected as the first arc R1, then when the arc-shaped grinding surface is tangent to the theoretical surface to be polished L1, another position on it and the surface of the workpiece A are tangent to the inside of the actual point T2, indicating that in the process of the grinding device 2 moving from the high point P1 to the end of the weld, the weld near the actual point T2 can be fully polished without polishing the theoretical surface to be polished, thus resulting in a better grinding effect.

[0053] Further, Figure 6 For example, in Figure 6In the figure, the end face height of ear plate B is 8mm, the theoretical length is 20mm, and the actual length is 25mm. For three common grinding devices, the curvature radius of the arc grinding surface is 25mm, 30mm and 40mm respectively. Calculation and analysis show that only when the curvature radius is 25mm, the tangent point of the curvature circle and the surface of the workpiece is located on the side of the actual point T2 close to the ear plate B. Therefore, it should be determined that among these three specifications of grinding tools, only the one with a curvature radius of 25mm on the arc grinding surface meets the requirements.

[0054] In summary, the curvature radius of the arc-shaped polished surface has a critical case, that is, the tangent point between the arc-shaped polished surface and the surface of the workpiece A coincides with the actual point T2. The curvature radius at this time is the maximum acceptable curvature radius, which is called the critical curvature radius. When selecting the curvature radius of the polished surface, it only needs to be less than or equal to the critical curvature radius.

[0055] In some embodiments, a plurality of ear plates B are welded on the workpiece A, and determining the curvature radius of the arc-shaped grinding surface of the grinding device 2 according to the theoretical surface to be grinded includes: determining a plurality of curvature radii of the plurality of arc-shaped grinding surfaces according to a plurality of size parameters of the plurality of ear plates B, respectively, and taking the minimum value of the plurality of curvature radii as the curvature radius of the arc-shaped grinding surface of the grinding device 2.

[0056] Specifically, in the case where multiple ear plates B are welded on the workpiece A and the specifications of each ear plate B are different, the corresponding multiple critical curvature radii can be calculated for the multiple ear plates B respectively, so that the curvature radius of the arc-shaped grinding surface is less than or equal to the minimum value of the multiple critical curvature radii. In this way, the arc-shaped grinding surface can be suitable for the grinding of all welds, and there is no need to switch to different grinding devices according to changes in the specifications of the ear plates B during the grinding process, thereby improving the grinding efficiency.

[0057] In some embodiments, the weld grinding method further includes: obtaining the weld width of the actual weld W in the thickness direction Y of the ear plate B, and the size of the arc-shaped grinding surface in the thickness direction Y of the ear plate B is greater than or equal to the weld width.

[0058] With such a configuration, the entire weld can be polished at one time in the weld width direction, or in the thickness direction Y of the ear plate B during the polishing process, thereby improving the polishing efficiency and reducing the inconvenience caused by multiple polishings required due to the reduction in the size of the arc polishing surface in the thickness direction Y of the ear plate B.

[0059] It is worth understanding that, in the case where multiple ear plates B are welded on the workpiece A and the specifications of each ear plate B are different, the weld widths of multiple welds can be obtained separately, so that the size of the arc-shaped grinding surface in the thickness direction Y of the ear plate B is greater than or equal to the minimum value of the multiple weld widths. In this way, the arc-shaped grinding surface can be suitable for the grinding of all welds, and there is no need to switch to different grinding devices according to changes in the specifications of the ear plate B during the grinding process, thereby improving the grinding efficiency.

[0060] In some embodiments, obtaining the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device 2 moving along the actual surface to be grinded includes: obtaining the starting point coordinates and starting point posture based on point cloud data processing technology.

[0061] Specifically, the starting point coordinates and the starting point posture can be recorded together as [X1, Y1, Z1, α1, β1, γ1], where X1, Y1, Z1 can determine the specific position of the grinding device 2 in the three-dimensional space when it starts grinding. Further, X1, Y1, Z1 quantify the position of the upper edge of the end face of the ear plate B, which is also the position where the weld and the upper edge of the end face of the ear plate B meet. α1, β1, γ1 reflect the posture angle of the grinding device 2 placed at the upper edge of the end face of the ear plate B. Based on this, the starting point on the moving path of the grinding device 2 and the placement posture at the starting point can be accurately obtained, improving the controllability of the grinding process.

[0062] In some embodiments, obtaining the starting coordinates, starting posture, end point coordinates and end point posture of the grinding device 2 moving along the actual surface to be polished includes: obtaining the end point coordinates and end point posture based on point cloud data processing technology, and the end point posture is configured as follows: in the projection plane perpendicular to the thickness direction Y of the ear plate B, at the end point coordinates, the line connecting the contact point of the arc-shaped grinding surface with the actual weld W and the center of the curvature circle of the arc-shaped grinding surface is perpendicular to the surface of the workpiece A.

[0063] Specifically, the end point coordinates and the end point posture can be recorded together as [X2, X2, X2, α2, β2, γ2], where X2, Y2, and Z2 can determine the specific position of the grinding device 2 in three-dimensional space when grinding is completed. Further, X2, Y2, and Z2 quantify the position where the end of the actual weld W intersects with the surface A of the workpiece. α2, β2, and γ2 reflect the posture angle of the grinding device 2 when grinding to the end of the weld. The posture angle at this time is set to make the line connecting the contact point between the arc-shaped grinding surface and the actual weld W and the center of the curvature circle of the arc-shaped grinding surface perpendicular to the surface of the workpiece A, which can effectively achieve a smooth transition of the welding surface grinding, and improve the problem of damage to the parent material due to unreasonable grinding posture. In some embodiments, the moving trajectory of the grinding device 2 is obtained according to the starting point coordinates, the starting point posture, the end point coordinates and the end point posture, and the grinding device 2 is controlled to move for grinding according to the moving trajectory, including: calculating multiple trajectory points of the grinding device 2 in the process of moving from the starting point coordinates to the end point coordinates based on the interpolation principle, and controlling the grinding device 2 to move along the multiple trajectory points in sequence for grinding.

[0064] Specifically, after determining two sets of data [X1, Y1, Z1, α1, β1, γ1] and [X2, X2, X2, α2, β2, γ2], multiple trajectory points in the moving process can be determined based on the interpolation principle, where the data of the nth trajectory point can be expressed as follows:

[0065]

[0066] The grinding device 2 can obtain the specific data of multiple track points according to the above formula, so that the grinding device 2 can move along the multiple track points in sequence to complete the smooth grinding of the weld. The moving track of the arc-shaped grinding surface during the grinding process is as follows: Figure 7 As shown in the figure. The weld surface L3 after grinding is as follows Figure 8 As shown in the figure, a circular arc is formed at the end of the weld to achieve a smooth transition, effectively reducing the stress concentration phenomenon and significantly improving the fatigue life of the structural parts.

[0067] Moreover, combined with the above-mentioned method for selecting the radius of curvature of the grinding surface, the specifications of the grinding device can be reasonably selected according to different dovetail specifications, which can meet the grinding of different weld sizes, achieve high consistency and repeatability, and ensure the stable quality of each batch of products.

[0068] refer to Figure 1 and 2The present application also provides a weld grinding system, and the welding connection relationship between the ear plate B and the workpiece A is as described above and will not be repeated here. The radius of curvature of the arc-shaped grinding surface of the grinding device 2 is determined according to the size parameters of the ear plate B. The grinding device 2 is mounted on the robotic arm 1. The robotic arm 1 is used to drive the grinding device 2 to move to grind the actual weld W. The control module is used to obtain the starting coordinates, starting posture, end coordinates and end posture of the grinding device 2 moving along the actual surface to be polished, and to obtain a moving trajectory based on the starting coordinates, starting posture, end coordinates and end posture to control the movement of the robotic arm 1 so that the grinding device 2 moves according to the moving trajectory for grinding.

[0069] The grinding device 2 is mounted on the robot arm 1, and the movement of the robot arm 1 can drive the grinding device 2 to move, thereby achieving the grinding of the weld, improving the controllability of the grinding device 2 and improving the grinding accuracy.

[0070] On the other hand, an adaptive arc-shaped grinding surface is determined according to the size of ear plate B, so that the radius of curvature of the arc-shaped grinding surface is appropriate. Combined with the planning of the moving trajectory, the positive adaptive grinding of the dovetail weld of the boom can be effectively realized, thereby reducing the damage to the transition part between the bottom of the dovetail weld and the parent material, achieving a smooth transition, and reducing the need for manual trimming after automatic grinding, thereby realizing automatic grinding.

[0071] In some embodiments, the control module is configured to control the movement of the robot arm 1 to perform grinding according to the weld grinding method described above.

[0072] Specifically, the control module includes a camera and a controller. The camera takes pictures of the weld to generate point cloud data. The controller processes and analyzes the point cloud data to obtain the starting point coordinates, starting point posture, end point coordinates and end point posture as described above. These data can be recorded as the following formula, where Wn is the data of the nth trajectory point.

[0073]

[0074] The above formula can be used to control the movement of the robot arm 1, and accurately move to each trajectory point in sequence, so as to complete the smooth grinding of the weld. It can achieve precise control and automated operation of the grinding process, realize automated grinding of the weld, reduce manual participation in grinding, improve grinding efficiency and reduce labor costs. In addition, it is also helpful to reduce the health problems caused by dust and noise caused by manual grinding of workers. Reference Figure 2 In some embodiments, the weld grinding system further includes a force control device 3. The force control device 3 is disposed at the end of the robot arm 1. The grinding device 2 is drivingly connected to the force control device 3. The force control device 3 is configured to control the grinding device 2 to float up and down according to the concave and convex conditions of the surface to be grinded during the movement of the grinding device 2 along the surface to be grinded to stabilize the grinding force.

[0075] Specifically, the force control device 3 can enable the grinding device 2 to float up and down within a small range, effectively compensating for the problem of unstable grinding force caused by the appearance of the weld.

[0076] In some embodiments, the force control device enables the grinding device to achieve a floating range of 20 mm.

[0077] refer to Figure 2 In some embodiments, the weld grinding system further includes a mounting transition block 4, an electric spindle mounting block 5, and a grinding electric spindle 6. Specifically, the mounting transition block 4 is drivingly connected to the force control device 3, the electric spindle mounting block 5 is disposed on the mounting transition block 6, the electric spindle mounting block 5 is used to mount the grinding electric spindle 6, the grinding device 2 is rotatably disposed on the grinding electric spindle 6, and the grinding electric spindle 6 can drive the grinding device 2 to move along the axial direction of the grinding electric spindle 6.

[0078] In some embodiments, the grinding device 2 comprises a grinding wheel or a grinding belt.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present application can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present application, which should be included in the scope of the technical solution for protection in the present application.

Claims

1. A method for grinding a weld of a workpiece, wherein an ear plate (B) is welded to the workpiece (A), the ear plate (B) is vertically placed on the workpiece (A), and the ear plate (B) includes a bottom surface in contact with the surface of the workpiece (A) and an end surface arranged at the end of the bottom surface, an actual weld (W) is formed between the end surface of the ear plate (B) and the workpiece (A), the actual weld (W) extends from the end surface of the ear plate (B) along the length direction (X) of the ear plate (B) to the surface of the workpiece (A), the actual surface to be ground of the actual weld (W) is formed by the surface of the weld (W) away from the workpiece (A), the weld grinding method is used to grind the actual weld (W), and is characterized in that: The weld grinding method comprises the following steps: Obtaining the size parameters of the ear plate (B) and determining the curvature radius of the arc-shaped grinding surface of the grinding device (2) according to the size parameters; Obtaining the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device (2) moving along the actual surface to be ground; as well as The moving trajectory of the grinding device (2) is acquired according to the starting point coordinates, the starting point posture, the ending point coordinates and the ending point posture, and the grinding device (2) is controlled to move according to the moving trajectory to perform grinding.

2. The method for grinding a weld of a workpiece according to claim 1, characterized in that: Determining the curvature radius of the arc-shaped grinding surface of the grinding device (2) according to the size parameters comprises: calculating and obtaining a theoretical surface to be ground according to the size parameters, and determining the curvature radius of the arc-shaped grinding surface according to the theoretical surface to be ground.

3. The method for grinding a weld of a workpiece according to claim 2, characterized in that: Determining the curvature radius of the arc-shaped grinding surface of the grinding device (2) according to the theoretical surface to be polished includes: the curvature radius of the arc-shaped grinding surface is constructed so that the arc-shaped grinding surface is tangent to both the theoretical surface to be polished and the surface of the workpiece (A), and the tangent line between the arc-shaped grinding surface and the surface of the workpiece (A) is located on the side of the actual surface to be polished close to the ear plate (B).

4. The method for grinding a weld of a workpiece according to claim 1, characterized in that: A plurality of ear plates (B) are welded on the workpiece (A), and determining the curvature radius of the arc-shaped grinding surface of the grinding device (2) according to the theoretical surface to be ground comprises: determining a plurality of curvature radii of the arc-shaped grinding surfaces according to a plurality of size parameters of the plurality of ear plates (B), respectively, and taking the minimum value of the plurality of curvature radii as the curvature radius of the arc-shaped grinding surface of the grinding device (2).

5. The method for grinding a weld of a workpiece according to claim 1, characterized in that: The weld grinding method also includes: obtaining the weld width of the actual weld (W) in the thickness direction (Y) of the ear plate (B), and the size of the arc-shaped grinding surface in the thickness direction (Y) of the ear plate (B) is greater than or equal to the weld width.

6. The method for grinding a weld of a workpiece according to any one of claims 1 to 5, characterized in that: Acquiring the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device (2) moving along the actual surface to be ground comprises: acquiring the starting point coordinates and starting point posture based on point cloud data processing technology.

7. The method for grinding a weld of a workpiece according to any one of claims 1 to 5, characterized in that: Obtaining the starting coordinates, starting posture, end coordinates and end posture of the grinding device (2) moving along the actual surface to be ground comprises: obtaining the end coordinates and end posture based on point cloud data processing technology, wherein the end posture is configured such that, in a projection plane perpendicular to the thickness direction (Y) of the ear plate (B), at the end coordinate, a line connecting the contact point between the arc-shaped grinding surface and the actual weld (W) and the center of the curvature circle of the arc-shaped grinding surface is perpendicular to the surface of the workpiece (A).

8. The method for grinding a weld of a workpiece according to any one of claims 1 to 5, characterized in that: The moving trajectory of the grinding device (2) is obtained according to the starting point coordinates, the starting point posture, the end point coordinates and the end point posture, and the movement of the grinding device (2) for grinding is controlled according to the moving trajectory, which includes: calculating a plurality of trajectory points in the process of the grinding device (2) moving from the starting point coordinates to the end point coordinates based on the interpolation principle, and controlling the grinding device (2) to move along the plurality of trajectory points in sequence for grinding.

9. A weld grinding system, characterized in that: The workpiece (A) is welded with an ear plate (B), the ear plate (B) is vertically placed on the workpiece (A), and the ear plate (B) includes a bottom surface in contact with the surface of the workpiece (A) and an end surface arranged at the end of the bottom surface, an actual weld (W) is formed between the end surface of the ear plate (B) and the workpiece (A), the actual weld (W) extends from the end surface of the ear plate (B) along the length direction (X) of the ear plate (B) to the surface of the workpiece (A), the actual surface to be polished of the actual weld (W) is formed by the surface of the weld (W) away from the workpiece (A), and the polishing device (2) The curvature radius of the arc-shaped grinding surface is determined according to the size parameters of the ear plate (B); the grinding device (2) is installed on the mechanical arm (1); the mechanical arm (1) is used to drive the grinding device (2) to move so as to grind the actual weld (W); the control module is used to obtain the starting point coordinates, starting point posture, end point coordinates and end point posture of the grinding device (2) moving along the actual surface to be polished, and to obtain a movement trajectory according to the starting point coordinates, starting point posture, end point coordinates and end point posture to control the movement of the mechanical arm (1) so that the grinding device (2) moves according to the movement trajectory to perform grinding.

10. The weld grinding system according to claim 9, characterized in that: The actual weld (W) has a theoretical surface to be polished that is related to the size parameters of the lug (B), and the curvature radius of the arc-shaped polished surface is determined by the theoretical surface to be polished.

11. The weld grinding system according to claim 10, characterized in that: The radius of curvature of the arc-shaped grinding surface is constructed so that the arc-shaped grinding surface is tangent to both the theoretical surface to be polished and the surface of the workpiece (A), and the tangent line between the arc-shaped grinding surface and the surface of the workpiece (A) is located on the side of the actual surface to be polished close to the ear plate (B).

12. The weld grinding system according to any one of claims 9 to 11, characterized in that: The control module is configured to control the movement of the robot arm (1) to perform grinding according to the weld grinding method according to any one of claims 6 to 8.

13. The weld grinding system according to any one of claims 9 to 11, characterized in that: The mechanical arm (1) further comprises a force control device (3), wherein the force control device (3) is arranged at the end of the mechanical arm (1), and the grinding device (2) is drivingly connected to the force control device (3). The force control device (3) is configured to control the grinding device (2) to float up and down according to the concave and convex conditions of the surface to be polished during the movement of the grinding device (2) along the surface to be polished, so as to stabilize the grinding force.

14. The weld grinding system according to any one of claims 9 to 11, characterized in that: The grinding device (2) comprises a grinding wheel or a grinding belt.

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