An automatic welding control system and method for a transformer oil tank production line

Abstract

The present application relates to the technical field of welding control, and particularly relates to an automatic welding control system and method for a transformer oil tank production line, wherein the automatic welding method comprises the following steps: obtaining a three-dimensional image of a positioning welding piece; determining a welding point position in a target welding area based on the three-dimensional image and a preset three-dimensional image; determining a rotating mode based on the target welding area position and a moving welding piece direction; determining a clamping position based on the rotating mode and the welding point position; butting the positioning welding piece and the moving welding piece; detecting an actual bevel angle and a butt joint gap of the butting position; determining a rotation angle or a moving amount of the moving welding piece based on the actual bevel angle and the butt joint gap; detecting a welding seam angle inclination of the welding piece; and determining a welding angle based on the welding seam angle inclination. The present application improves the welding precision and efficiency of each component of the welding piece by determining the rotating mode and the clamping position, and determining the welding angle based on the welding seam angle inclination.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding control, in particular to an automatic welding control system and method for a transformer oil tank production line. BACKGROUND

[0002] The transformer oil tank is the installation basis of the transformer oil pillow, and is formed by a steel plate welding structure to constitute a pressure container, and the oil pillow is horizontally installed on the top of the transformer oil tank to adjust the oil level. The oil pillow adopts a capsule type, diaphragm type or corrugated type structure, which can effectively isolate the oil from the air contact and slow down the oil quality deterioration. The oil tank and the oil pillow are connected through a metal pipeline, and a gas relay is installed therebetween to realize fault detection. The oil tank structure is divided into a bell type and a hanging body type according to different capacities, and the full-closed bell type welding process is generally used for large transformers. The main body of the oil tank is a cylindrical container welded by a steel plate, and the bell type structure is used for medium and large transformers to realize full-closed welding, and the hanging body type design is used for small transformers. The oil pillow is connected to the oil tank through a curved connecting pipe, and the volume of the oil pillow accounts for about 8% to 10% of the oil volume of the oil tank. At present, due to the continuous promotion of the power grid upgrading in the high-altitude areas of western China and the "West-East Electricity Transmission" project, the demand for transformer oil tanks in high-altitude areas has increased.

[0003] Chinese Patent Publication No. CN103770323A discloses an automatic welding device and method for thin-walled aluminum alloy oil tank ring seam low deformation, which is used for ring welding the tank body end plate and the tank body plate into one body. The present application simultaneously cools the welding seam peripheral area before and after welding, increases the cooling speed of the welding seam peripheral base material, and reduces the deformation amount before and after welding. The robot cooperative control mode is adopted to ensure the cooling effect and the accessibility of the welding position, which is beneficial to realize the full-automatic welding of the peripheral welding seam. When the present application is used for welding the thin-walled aluminum alloy oil tank, the solidification process can be omitted, and the welding efficiency is improved by 20% to 40%. The present application can realize the welding and manufacturing of thin-walled aluminum alloy oil tanks of different sizes, meet the automatic high-precision welding of various aluminum alloy oil tank ring seams, improve the welding stability, and efficiently and quickly realize the robot welding of thin-walled components.

[0004] It can be seen that the prior art has the following problems: in the automatic welding process, due to the lack of key steps of determining the rotating mode and clamping position in the target welding area, and determining the welding angle according to the welding seam angle inclination, the position positioning speed of each part of the welded part is slow, the welding angle is easy to deviate, and the welding cycle is prolonged and the welding precision is reduced. SUMMARY

[0005] To this end, the present application provides an automatic welding control system and method for a transformer oil tank production line to overcome the problem in the prior art that, in the automatic welding process, due to the lack of a key step of determining a rotating mode and a clamping position in a target welding area and determining a welding angle according to a welding seam angle inclination, the position positioning speed of each component of a welded part is slow, the welding angle is prone to deviation, and thus the welding cycle is prolonged and the welding precision is reduced.

[0006] To achieve the above-mentioned object, the present application provides an automatic welding method for a transformer oil tank production line, comprising,

[0007] Based on a plurality of industrial cameras arranged in a surround manner to capture a stereoscopic three-dimensional image of a positioning welded part, a welding point position in a target welding area is determined based on the stereoscopic three-dimensional image and a preset three-dimensional image;

[0008] A welding point position vector is determined based on the target welding area position and a moving welded part direction;

[0009] A rotating mode is determined based on the welding point position vector, and a clamping position is determined based on the rotating mode and the position of the welding point position in the target welding area;

[0010] The positioning welded part is butted with the moving welded part to determine a welding point position based on the rotating mode and the clamping position of the positioning welded part, an actual bevel angle of the butted position and a butted gap are detected, and the rotating angle of the moving welded part and the moving amount of the moving welded part are adjusted based on the actual bevel angle and the butted gap;

[0011] Based on the welded part after butting, a welding seam angle inclination of the welded part is detected, and a welding angle is determined based on the welding seam angle inclination;

[0012] The rotating mode includes a full rotation mode and a front rotation mode, the full rotation mode is a rotating mode of the positioning welded part with a first rotating shaft, and the front rotation mode is a rotating mode with a second rotating shaft; the first rotating shaft is a Z-axis perpendicular to a welding surface, and the second rotating shaft is an X-axis parallel to the welding surface, and the X-axis coincides with the moving direction of the moving welded part.

[0013] Further, the process of determining the welding point position in the target welding area based on the stereoscopic three-dimensional image and the preset three-dimensional image comprises,

[0014] Actual physical coordinates of the welding point position are recognized and extracted based on the stereoscopic three-dimensional image;

[0015] The actual physical coordinates are compared with a standard position of the target welding area in the preset three-dimensional image to determine the specific positioning of the welding point position in the target welding area, and a target calibration position of the welding point position in the target welding area is obtained.

[0016] Further, the process of determining the welding point position vector based on the target welding area position and the moving welding piece direction comprises,

[0017] calculating the actual distance of the welding point position vector based on the target calibration position and the moving welding piece position, comparing the actual distance with the preset safe welding distance to obtain a distance comparison result, and determining the rotation mode based on the distance comparison result.

[0018] The preset safe welding distance is a threshold value of the modulus of the welding point position vector.

[0019] Further, the process of determining the rotation mode based on the distance comparison result comprises,

[0020] based on the actual distance being greater than the preset safe welding distance, determining the rotation mode based on the welding point position vector;

[0021] based on the actual distance being less than or equal to the preset safe welding distance, maintaining the current relative position state of the moving welding piece and the welding point position.

[0022] Further, the process of determining the welding point position by abutting the moving welding piece with the positioning welding piece based on the determined rotation mode and the clamping position comprises,

[0023] based on the welding point position being in the same direction as the moving direction of the moving welding piece, adjusting the welding point position by the front rotation mode;

[0024] based on the welding point position being in the perpendicular direction of the moving direction of the moving welding piece, adjusting the welding point position by the full rotation mode;

[0025] based on the rotation mode being unable to adjust the welding point position, adjusting the translation position of the moving welding piece to adapt to the welding point position.

[0026] Further, the process of determining the clamping position based on the rotation mode and the position of the welding point in the target welding area comprises,

[0027] based on the position of the welding point in the target welding area, determining the clamping position by excluding non-clamping surfaces and continuing the welding point position;

[0028] The non-clamping surface is a curved welding surface of the welding piece, and the continuing welding point position is a point position that needs to be continuously welded after the welding of the current welding point position is completed.

[0029] Further, the process of detecting the actual bevel angle and the abutment gap of the abutment position comprises,

[0030] Based on the comparison result of the bevel angle, if the comparison result of the butt joint gap is qualified, the actual bevel angle is adjusted to be qualified;

[0031] Based on the comparison result of the bevel angle, if the comparison result of the butt joint gap is unqualified, the moving amount of the welding piece in the direction perpendicular to the welding direction is adjusted to make the butt joint gap qualified;

[0032] Based on the comparison result of the bevel angle, if the comparison result of the butt joint gap is unqualified, the moving amount of the welding piece in the direction perpendicular to the welding direction is adjusted to make the butt joint gap qualified;

[0033] The comparison result of the bevel angle is the comparison result of the actual bevel angle and the standard bevel angle; the comparison result of the butt joint gap is the comparison result of the butt joint gap and the standard gap; and the welding direction refers to the direction perpendicular to the butt joint edge.

[0034] Further, the process of detecting the weld angle inclination of the welding piece comprises,

[0035] The weld angle inclination is detected on the plane perpendicular to the center line of the welding angle, and the welding angle is determined based on the weld angle inclination;

[0036] The weld angle inclination is the included angle between the plane where the center line of the welding angle is located and the plane where the welding surface is located.

[0037] Further, the process of determining the welding angle based on the weld angle inclination comprises,

[0038] The weld angle inclination is compared with the inclination threshold value;

[0039] Based on the weld angle inclination being less than or equal to the inclination threshold value, the current welding angle is determined as the final welding angle;

[0040] Based on the weld angle inclination being greater than the inclination threshold value, a compensation angle is calculated according to the weld angle inclination, and the welding angle of the welding mechanism is adjusted so that the compensated welding angle is perpendicular to the plane where the welding surface is located;

[0041] The inclination threshold value is set according to the sealing and strength requirements of the transformer tank welding, and the compensation angle is equal to the difference between the weld angle inclination and the inclination threshold value.

[0042] The application also provides an automatic welding control system for a transformer tank production line, comprising,

[0043] An image acquisition module is used to collect a three-dimensional image of the positioning welding piece;

[0044] a welding point position locating module connected with the image acquisition module, configured to compare the stereoscopic three-dimensional image with the preset three-dimensional image to determine the position of the welding point in the target welding area;

[0045] a path planning module connected with the welding point position locating module, configured to calculate a welding point vector according to the position of the target welding area and the direction of the moving welding piece;

[0046] an execution module connected with the path planning module, configured to control the mechanical arm to butt the locating welding piece with the moving welding piece according to the determined rotating mode and the clamping position;

[0047] a parameter detection and adjustment module connected with the execution module, configured to detect the actual bevel angle and the butt gap of the butt position, and output a rotating angle adjustment instruction or a moving amount adjustment instruction to the butt execution module;

[0048] a welding angle determining module connected with the parameter detection and adjustment module, configured to detect the inclination of the welding seam angle, calculate and output a welding angle adjustment instruction based on the inclination;

[0049] a main control module connected with the image acquisition module, the welding point position locating module, the path planning module, the execution module, the parameter detection and adjustment module, and the welding angle determining module, respectively, configured to coordinate the timing and logic of the welding process.

[0050] Compared with the prior art, the beneficial effects of the present application are that, by the layout of 4 industrial cameras and synchronous shooting, the details of the tank body and the tank cover can be captured in all directions, combined with camera parameter correction and edge detection, irrelevant background can be effectively removed, focusing on the key area of the joint edge, laying a precise foundation for subsequent processing. In the feature point extraction and stereo matching process, with the help of the uniqueness and rotation invariance of feature points, as well as the accurate identification of the same point pair and the elimination of mismatched points, the reliable association of multi-view image information is ensured. Multi-view three-dimensional coordinate calculation and point cloud fusion technology, the final complete three-dimensional model can truly restore the geometric shape of the welded part, and provide high-precision three-dimensional data support for the positioning of the welding point, solving the problem of incomplete information and insufficient positioning accuracy of traditional single-view imaging. From the accurate positioning of the welding point in the target welding area, to determining the welding point vector based on the target position and moving direction, to selecting the rotation mode and clamping position according to the direction, each step relies on accurate three-dimensional data to realize the logic closed loop. The detection and adjustment of the actual bevel angle and the joint gap during the docking process, as well as the optimization of the welding angle based on the inclination of the weld angle, form a complete self-adaptive adjustment mechanism, which can dynamically adapt to the slight deviation or deformation of the welded part. The flexible application of the two rotation modes can solve the positioning adjustment requirements of different directions, ensuring the accurate docking of the welded part and the appropriate welding angle. This method realizes the full-process automation and high precision of the transformer oil tank welding from image acquisition, point positioning to welding parameter adjustment, effectively improves the welding efficiency and weld quality stability, reduces the error caused by manual intervention, meets the strict requirements of the transformer oil tank on the welding sealing performance and structural strength, and provides reliable technical support for large-scale and high-quality oil tank production.

[0051] Further, with the help of the surrounding layout of the multi-camera system, the details of the box and the box cover can be captured comprehensively, and the key geometric features such as the V-shaped groove vertex corresponding to the welding point can be accurately identified by combining feature point extraction and edge detection technology, providing a reliable basis for the extraction of actual physical coordinates, ensuring that the coordinate data can truly reflect the actual position of the welded part. By comparing the actual physical coordinates with the standard position in the preset three-dimensional model, the deviation between the two can be clearly quantified, and the specific positioning of the welding point in the target welding area can be determined. The subjective and error-prone nature of traditional visual positioning is avoided, making the deviation evaluation more objective and accurate. The deviation within the allowable range determines the position accuracy of the welding point, ensuring that it is within the reasonable range of the target welding area, and also retains a certain flexibility to adapt to the slight deformation or installation error of the workpiece in actual production, avoiding the problem of low adjustment efficiency caused by excessive pursuit of absolute accuracy. This process realizes the full-process digitization and automation of the welding point from image recognition to accurate positioning, providing a high-precision position reference for subsequent welding path planning, posture adjustment and other links, effectively ensuring the accuracy and consistency of the welding point positioning, and laying a solid foundation for improving the welding quality and production efficiency of the transformer oil tank

[0052] Further, by clearly defining the spatial relationship between the target calibration position and the moving welding part, and taking the preset safe welding distance as the reference, the precise determination of the welding point vector is realized. The setting of the preset safe welding distance provides a clear limit for the position adjustment of the moving welding part, effectively avoiding the collision risk caused by too close distance, ensuring the safety of the equipment and the workpiece, and building a strong safety line for subsequent welding operation. By calculating the difference between the actual distance and the preset safe distance, it can be clearly judged whether the moving welding part has reached the welding preparation state, and the moving direction can be guided without unnecessary operation, reducing invalid adjustment, speeding up the preparation rhythm before welding, and improving the operation efficiency of the whole process. Taking the target calibration position as the reference, the welding point vector is determined combined with the real-time position of the moving welding part, ensuring that the direction pointing is highly consistent with the actual docking demand, providing a reliable direction basis for subsequent steps such as selection of rotation mode and determination of clamping position, which helps to improve the accuracy of the whole welding process. By comparing the distance to determine the state, the system can be easily automated, reducing the uncertainty of manual intervention, making the operation in the welding preparation stage more stable and controllable, and laying a solid foundation for high-quality welding.

[0053] Further, by comparing the actual distance with the preset safe welding distance, clear adjustment logic is formed, ensuring that the mobile welding part and the welding point are always in a safe and appropriate relative position, avoiding the risk of collision caused by too close distance, and preventing low efficiency caused by too far distance. For deviations in different directions, flexible use of front rotation and full rotation is adopted to achieve precise adaptation to position deviation. Front rotation is used for deviation in the same direction of the moving direction, which efficiently shortens the distance by adjusting the pitch angle, ensuring the accuracy of position calibration along the conveying direction; full rotation focuses on the deviation in the vertical direction, and the offset is corrected by horizontal torsion, ensuring the accuracy of the groove alignment. The targeted application of the two rotation modes improves the efficiency and accuracy of position adjustment. When the rotation mode is limited, the translation position of the mobile welding part is adjusted to adapt, forming a complete adjustment closed loop, avoiding adjustment stagnation due to equipment limitations, and ensuring that regardless of the type and size of the deviation, the actual distance can meet the preset requirements through reasonable combination adjustment. The whole process of adaptive adjustment from distance judgment to deviation correction is realized, which not only ensures the safety of welding operation, but also improves the accuracy of welding point docking, providing reliable guarantee for the stable performance of subsequent welding process.

[0054] Further, by accurately identifying the position of the welding point in the target welding area, and combining the rotation mode requirements, the non-clamping surface and the continued welding point area are scientifically excluded, which can effectively ensure the rationality and safety of the clamping position. Excluding non-clamping surfaces with curvature can avoid slipping during clamping, ensure stable clamping of the welding part, reduce position deviation caused by unstable clamping, and provide a basis for the accuracy of subsequent welding operation. Excluding the continued welding point and its surrounding area reserves sufficient welding operation space, effectively preventing interference between the mechanical arm and the clamping jaw during subsequent welding, ensuring smooth welding process and reducing unnecessary adjustment time. Combined with the special requirements of the clamping position for the rotation mode, such as symmetrical distribution on both sides of the rotation axis and maintaining a certain distance during front rotation, the clamping position can adapt to the rotation requirements, ensuring force balance of the welding part during rotation, avoiding deformation or position deviation of the welding part caused by uneven force, and ensuring accurate alignment of the welding point after rotation, improving the quality of welding preparation. Reasonable clamping position does not need to be re-adjusted when switching welding points, significantly improving the efficiency of the overall welding process, reducing time loss caused by repeated operations, and providing strong support for large-scale production.

[0055] Further, by adjusting the strategy, the butt joint precision of the welded part is precisely controlled, which has significant practical value. For the situation that the groove angle is unqualified but the butt joint gap is qualified, by adjusting the rotation angle for correction, the groove angle can be quickly qualified without affecting the qualified gap, ensuring that the welding surface angle meets the process requirements, creating conditions for the uniform formation of the molten pool during subsequent welding. When the groove angle is qualified but the butt joint gap is unqualified, only the movement perpendicular to the welding direction is adjusted, which can accurately eliminate the gap deviation while maintaining the correct angle, avoiding new deviations that may be caused by adjusting the angle, ensuring the accuracy of the gap size, and being beneficial to control the welding material filling amount and the welding seam forming quality. For the situation that both are unqualified, the step-by-step strategy of adjusting the angle first and then adjusting the gap is adopted, which effectively avoids mutual interference in the adjustment process, ensures that the groove angle, a key parameter affecting the welding strength, is qualified first, and ensures the sealing performance of welding through subsequent gap adjustment, so that the final butt joint state fully meets the process standard. The adjustment mode considering different situations balances efficiency and precision, can flexibly cope with different types of butt joint deviations, and significantly improves the quality stability of transformer oil tank welding, providing reliable support for ensuring the structural strength and sealing performance of the oil tank.

[0056] Further, by precisely detecting the inclination of the welding seam angle and adjusting the welding angle accordingly, reliable support is provided for ensuring welding quality. With the help of laser line scanning sensor detection in a specific plane, the inclination degree of the welding seam deviating from the ideal state can be accurately captured, and combined with the setting of inclination threshold, scientific judgment of whether the welding angle needs to be adjusted can be realized. When the inclination is within the allowed range, the current welding angle is directly used, which simplifies the operation process while ensuring stable welding seam forming; when the inclination is out of limit, the compensation angle is calculated and the welding mechanism is adjusted, so that the welding gun is always perpendicular to the actual welding surface, effectively avoiding problems such as uneven depth of both sides of the welding seam and poor forming caused by angle deviation. It can adapt to the small pitch deviation during butt joint of the welded part, and meet the strict requirements of transformer oil tank on welding seam sealing performance and structural strength, reduce quality hidden dangers such as leakage, and improve the stability and reliability of the welding process, providing strong support for subsequent use safety. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 Flowchart of the automatic welding method for the transformer oil tank production line in the embodiment;

[0058] Figure 2 Flowchart of the automatic welding method for the transformer oil tank production line in the embodiment;

[0059] Figure 3 Flowchart of the automatic welding method for the transformer oil tank production line in the embodiment;

[0060] Figure 4 Flow chart for determining welding angle process of automatic welding method for transformer oil tank production line in the embodiment;

[0061] Figure 5 Structure schematic diagram of automatic welding control system for transformer oil tank production line in the embodiment;

[0062] Figure 6 Structure schematic diagram of welding device for automatic welding method for transformer oil tank production line in the embodiment. DETAILED DESCRIPTION

[0063] In order to make the objects and advantages of the present application clearer, the following further describes the present application with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0064] The preferred embodiments of the present application are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present application and are not used to limit the protection scope of the present application.

[0065] It should be noted that, in the description of the present application, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating the direction or positional relationship terms are based on the direction or positional relationship shown in the drawings, which is only for the convenience of description, and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0066] In addition, it should also be noted that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0067] Please refer to Figure 1 as shown, Figure 1 Flow chart of automatic welding method for transformer oil tank production line in the embodiment;

[0068] The embodiment provides an automatic welding method for a transformer oil tank production line, comprising,

[0069] Step S1, based on several industrial cameras, a surround layout is shot to obtain a stereoscopic three-dimensional image of the positioning welding piece, and based on the stereoscopic three-dimensional image and a preset three-dimensional image, the welding point position is determined in the target welding area position;

[0070] Step S2, based on the target welding area position and the moving welding piece direction, a welding point position vector is determined;

[0071] Step S3, based on the welding point position vector, a rotation mode is determined, based on the rotation mode and the position of the welding point in the target welding area, a clamping position is determined;

[0072] Step S4, based on the rotation mode and the clamping position of the positioning welding piece that have been determined, the positioning welding piece is butted with the moving welding piece to determine the welding point position, the actual bevel angle and the butt gap of the butt joint position are detected, and based on the actual bevel angle and the butt gap, the rotation angle of the moving welding piece and the movement amount of the moving welding piece are adjusted;

[0073] Step S5, based on the welded piece after butt joint, the weld angle inclination of the welded piece is detected, and based on the weld angle inclination, a welding angle is determined;

[0074] The rotation mode includes a full rotation mode and a front rotation mode, the full rotation mode is a rotation mode of the positioning welding piece with a first rotation axis, and the front rotation mode is a rotation mode with a second rotation axis; the first rotation axis 1 is a Z axis perpendicular to the welding surface, and the second rotation axis 2 is an X axis parallel to the welding surface.

[0075] In the automatic welding production line of the transformer oil tank, the welding pieces to be positioned are the oil tank body and the oil tank cover, and the stereoscopic three-dimensional images of the two are obtained through a multi-camera system for subsequent welding point positioning; wherein the oil tank body is a cuboid cylindrical structure with a size of 1500mmx1000mmx800mm, and the oil tank cover is a flat plate structure with a size of 1600mmx1100mm,

[0076] Four high-resolution industrial cameras are arranged in a surround layout around the welding station, the centers of the lenses of all the cameras are flush with the height of the edge of the tank body, and the welding area is completely shot,

[0077] Among them, the front camera C1 is located 1.5m in front of the tank body, the optical axis is horizontally aligned with the center of the front of the tank body, and the front wall and the edge bevel of the tank body are shot;

[0078] The rear camera C2 is located 1.5m behind the tank body, symmetrically with C1, and the rear wall and the edge of the tank body are shot;

[0079] Left camera C3: Located 1.2m to the left of the enclosure, with its optical axis tilted 15° to the right, covering the edge where the left side wall of the enclosure meets the enclosure lid;

[0080] Right camera C4: Located 1.2m to the right of the enclosure, symmetrical to C3, covering the edge where the right side wall of the enclosure meets the lid.

[0081] Please see Figure 2 As shown, Figure 2 This is a flowchart of an automated welding method for a transformer tank production line, as shown in the embodiment.

[0082] This embodiment provides a method for acquiring a three-dimensional image of a positioning welded component. Step S1 includes:

[0083] Step S11: Control 4 cameras to take pictures simultaneously, with the shooting time difference controlled within 0.1ms to avoid image misalignment caused by slight shaking of the workpiece. Each camera takes pictures of the edge contour of the welded part, the welding bevel angle of the box body, and the edge flatness of the box cover.

[0084] Step S12: Correct the image based on camera intrinsic parameters, locate the outline of the welded part through edge detection algorithm, crop the background area, and retain only the docking edge between the box body and the box cover;

[0085] Step S13: Extract 500-800 feature points from each of the four preprocessed images. Based on the scale and rotation invariance of the feature points, perform stereo matching between the images in the front-back direction of C1 and C2 and the left-right direction of C3 and C4 to obtain corresponding point pairs and remove mismatched points.

[0086] Step S14: Based on the principle of binocular vision, using camera extrinsic parameters, the three-dimensional coordinates of matching point pairs are calculated by camera calibration according to the relative position relationship. Multi-view data are fused, and the three-dimensional point clouds calculated by C1-C2 and C3-C4 are fused to obtain a complete three-dimensional point cloud of the welded part.

[0087] Step S15: Mesh the three-dimensional point cloud of the welded part to generate a three-dimensional image of the welded part.

[0088] Among them, feature points are pixels in an image that are unique, stable, and repeatable, and can represent key geometric information of the object's surface; rotation invariance means that when the object is rotated, the way feature points are described will not change significantly, and they can still be accurately identified as the same feature point; corresponding point pairs can be understood as the imaging of point P1 in C1 and point P2 in C2 as the same physical point.

[0089] By the 4 industrial cameras around the layout and synchronous shooting, the details of the tank body and the tank cover can be captured in all directions, combined with the camera parameter correction and edge detection, the irrelevant background can be effectively removed, and the key area of the butt joint edge is focused, which lays a precise foundation for subsequent processing. In the feature point extraction and stereo matching process, with the help of the uniqueness and rotation invariance of feature points, as well as the accurate identification of the same point pair and the elimination of mismatched points, the reliable association of multi-view image information is ensured. Multi-view three-dimensional coordinate calculation and point cloud fusion technology can finally generate a complete three-dimensional model, which can truly restore the geometric shape of the welded part, and provide high-precision three-dimensional data support for the positioning of the welding point, solving the problem of incomplete information and insufficient positioning accuracy of traditional single-view imaging. From the accurate positioning of the welding point in the target welding area to the determination of the welding point vector based on the target position and the moving direction, and then to the selection of the rotation mode and the clamping position according to the direction, each step relies on accurate three-dimensional data to realize the logic closed loop. The detection and adjustment of the actual bevel angle and the butt joint gap during the butt joint process, as well as the optimization of the welding angle based on the inclination of the weld angle, form a complete self-adaptive adjustment mechanism, which can dynamically adapt to the small deviation or deformation of the welded part. The flexible application of the two rotation modes can solve the positioning adjustment demand in different directions, ensuring the accurate butt joint of the welded part and the appropriate welding angle. This method realizes the full-process automation and high precision of the transformer oil tank welding from image acquisition, point positioning to welding parameter adjustment, effectively improves the welding efficiency and the stability of the weld quality, reduces the error caused by manual intervention, meets the strict requirements of the transformer oil tank on the welding sealing and structural strength, and provides reliable technical support for large-scale and high-quality oil tank production.

[0090] Specifically, in step S1, the process of determining the position of the welding point in the target welding area based on the three-dimensional image and the preset three-dimensional image includes,

[0091] Identifying and extracting the actual physical coordinates of the welding point based on the three-dimensional image;

[0092] Comparing the actual physical coordinates with the standard position of the target welding area in the preset three-dimensional image to determine the specific positioning of the welding point in the target welding area, and obtaining the target calibration position of the welding point in the target welding area.

[0093] A multi-camera system is adopted to obtain the three-dimensional model of the tank body and the tank cover by surrounding the layout of 4 industrial cameras. The three-dimensional coordinates take the center of the production line workbench as the origin, the X-axis as the horizontal left-right direction, the Y-axis as the horizontal front-back direction along the production line conveying direction, and the Z-axis as the vertical direction.

[0094] Please refer to Figure 3 , as shown in Figure 3A flow chart of a target welding zone position determination process for an automatic welding method for a transformer oil tank production line in an embodiment;

[0095] In this embodiment, the corner joint weld between the vertical wall of the transformer oil tank body and the horizontal tank cover is taken as an example. The target welding zone is the 90° included angle edge with a length of 2000 mm. The preset welding point positions are 20 welding point numbers W1 to W20 evenly distributed along the edge, with a design interval of 100 mm. The following is the process of determining the position of the W10 welding point in the target welding zone, including,

[0096] Step S21, extract the image feature points, combine the edge detection to locate the butt joint edge of the tank body and the tank cover, and identify the V-shaped groove vertex corresponding to the W10 welding point. The feature is the intersection of the two side groove edges. Analyze the three-dimensional point cloud data to obtain the actual physical coordinates of the W10 welding point position P1 W10 = (998.7, 1002.3, 501.1).

[0097] Step S22, preset the three-dimensional image as the three-dimensional model of the oil tank in the design stage, wherein the standard position of the W10 welding point is P2 W10 = (X = 1000, Y = 1000, Z = 500), wherein the point on the X-axis is 1000 mm to the right of the horizontal center of the workbench geometric origin of the welding point, perpendicular to the conveying direction of the moving welding part tank cover, and corresponds to the left and right direction position of the front side edge of the tank body, which is adapted to the width dimension of the tank body; the point on the Y-axis is 1000 mm in front of the workbench geometric center origin along the conveying direction of the production line, which corresponds to the front and rear direction position of the front side edge of the tank body, which is adapted to the length dimension of the tank body, and is aligned with the feeding path of the moving welding part; the point on the Z-axis is 500 mm above the workbench, which corresponds to the height direction position of the vertical wall of the tank body, which is adapted to the height dimension of the tank body, and is the vertex height of the butt joint groove of the tank body and the tank cover.

[0098] The standard position is determined according to the structural characteristics of the transformer oil tank and the welding process requirements. The tank body is a rectangular cylindrical structure 1500 mm x 1000 mm x 800 mm, and the tank cover is a flat plate structure 1600 mm x 1100 mm. X = 1000 mm, Y = 1000 mm, Z = 500 mm of P2 W10 are within the size range of the tank cover, and correspond to the edge intersection of the corner joint weld between the vertical wall of the tank body and the tank cover; the standard position is a key point of the three-dimensional model of the oil tank in the design stage of the preset three-dimensional image. In the subsequent actual welding, the actual welding point coordinate of the positioning welding part tank body needs to be compared with P2 W10 . For example, the actual coordinate P1 W10 = (998.7, 1002.3, 501.1) and P2 W10the deviation calculation to determine whether adjustment is needed, ensuring that the welding point is within the target welding area;

[0099] In step S23, the deviation of the actual physical coordinates from the standard position is calculated: ΔX = 998.7-1000 = -1.3mm, 1.3mm left along the X-axis, ΔY = 1002.3-1000 = 2.3mm, 2.3mm forward along the Y-axis, and ΔZ = 501.1-500 = 1.1mm, 1.1mm upward along the Z-axis.

[0100] In step S24, the deviation is within the allowable range, and the welding point is in a reasonable position within the target welding area, so no adjustment is needed. The allowable range is ±3mm.

[0101] With the surround layout of the multi-camera system, the details of the box and the box cover can be captured comprehensively, and combined with feature point extraction and edge detection technology, the key geometric features such as the vertex of the V-shaped groove corresponding to the welding point can be accurately identified, providing a reliable basis for the extraction of actual physical coordinates, and ensuring that the coordinate data can truly reflect the actual position state of the welding part. By comparing the actual physical coordinates with the standard position in the pre-set three-dimensional model, the deviation between the two can be clearly quantified, and the specific positioning of the welding point in the target welding area can be determined. The subjectivity and errors in traditional visual positioning, which rely on manual judgment, are avoided, making the deviation evaluation more objective and accurate. The deviation within the allowable range not only strictly controls the position accuracy of the welding point, ensuring that it is within the reasonable range of the target welding area, but also retains a certain flexibility, which can adapt to the slight deformation or installation error of the workpiece in actual production, avoiding the problem of low adjustment efficiency caused by excessive pursuit of absolute accuracy. This process realizes the full-process digitization and automation of the welding point from image recognition to accurate positioning, provides a high-precision position reference for subsequent welding path planning, posture adjustment and other links, effectively guarantees the accuracy and consistency of the welding point positioning, and lays a solid foundation for improving the welding quality and production efficiency of the transformer oil tank.

[0102] Specifically, in step S2, the process of determining the welding point vector based on the target welding area position and the direction of the moving welding part includes,

[0103] Based on the target calibration position and the position of the moving welding part, the actual distance of the welding point vector is calculated, and the distance comparison result is obtained by comparing the actual distance with the pre-set safe welding distance. The rotation mode is determined based on the distance comparison result.

[0104] The pre-set safe welding distance is a threshold value of the length of the welding point vector.

[0105] The mobile welding part is a box cover to be butt-jointed, and the positive direction along the Y-axis direction of the production line is forward. The current position is identified by a multi-camera system as K=(998.7, 1050.0, 501.1), and the butt-joint is formed with the box body along the positive direction of the Y-axis to form a 90° angle. The target calibration position is the precise coordinate of the W10 welding point, which is the reference point for welding. The mobile welding part, the box cover, changes the actual distance between the current position and the target calibration position. The preset safe welding distance is determined according to the welding process requirements, and in this embodiment, it is set to 30 mm, which refers to the shortest distance between the welding point and the mobile welding part that allows the welding operation to start. If the distance is less than this distance, it may cause a collision, and if it is greater, the position needs to be adjusted.

[0106] According to the two-point coordinate calculation in the three-dimensional coordinate, the actual distance between the current position of the box cover and the W10 target calibration position is 47.7 mm. The calculation process is not repeated here as it is prior art.

[0107] Since 47.7 mm is greater than 30 mm, it indicates that the mobile welding part, the box cover, has not yet reached the welding preparation position and needs to continue moving in the positive direction of the Y-axis until the actual distance is less than or equal to 30 mm. When the box cover moves to the actual distance equal to the preset safe welding distance, its position is K1=(998.7, 1032.3, 501.1). At this time, the welding point vector is the direction from the W10 target calibration position to the edge of the box cover.

[0108] By clearly defining the spatial relationship between the target calibration position and the mobile welding part, and taking the preset safe welding distance as the reference, the precise determination of the welding point vector is achieved. The setting of the preset safe welding distance provides a clear limit for the position adjustment of the mobile welding part, effectively avoiding the collision risk caused by too close distance, ensuring the safety of the equipment and the workpiece, and building a strong safety line for subsequent welding operations. By calculating the difference between the actual distance and the preset safe distance, it can be clearly judged whether the mobile welding part has reached the welding preparation state. Without additional operations, the moving direction can be guided, reducing unnecessary adjustments, speeding up the preparation pace before welding, and improving the overall process efficiency. Taking the target calibration position as the reference, the welding point vector is determined in combination with the real-time position of the mobile welding part, ensuring that the direction is highly consistent with the actual butt-joint requirement, providing a reliable directional basis for subsequent steps such as selection of rotation mode and determination of clamping position, which helps to improve the accuracy of the entire welding process. By comparing the distances to determine the state, the system can be easily automated, reducing the uncertainty of manual intervention, making the welding preparation stage more stable and controllable, and laying a solid foundation for high-quality welding.

[0109] Specifically, the process of determining the rotation mode based on the distance comparison result includes,

[0110] Based on the actual distance being greater than the preset safe welding distance, the rotation mode is determined based on the welding point vector.

[0111] If the actual distance is less than or equal to the preset safe welding distance, the current relative position state of the mobile welding piece and the welding point position is maintained.

[0112] Specifically, the process of determining the welding point position based on the rotation mode and the clamping position of the positioning welding piece and the mobile welding piece includes,

[0113] Based on the welding point position in the same direction of the mobile welding piece movement direction, the welding point position is adjusted by the front rotation mode;

[0114] Based on the welding point position in the perpendicular direction of the mobile welding piece movement direction, the welding point position is adjusted by the full rotation mode;

[0115] If the welding point position cannot be adjusted by the rotation mode, the translation position of the mobile welding piece is adjusted to adapt to the welding point position.

[0116] Front rotation mode: rotate around the X-axis, adjust the pitch angle of the box cover, adapt to the position deviation along the Y-axis direction,

[0117] Full rotation mode: rotate around the Z-axis, adjust the horizontal twist angle of the box cover, adapt to the deviation perpendicular to the Y-axis direction,

[0118] The welding point position is in the same direction of the movement direction, the Y-axis direction deviation, the box cover leads along the Y-axis direction, the actual distance is 47.7mm, but the X, Z-axis coordinates are consistent with the target calibration position, the relative position of the welding point position and the box cover of the mobile welding piece is in the same direction of the Y-axis, the front rotation mode is adopted, the box cover is controlled to tilt forward by 3° around the X-axis, the edge of the box cover is fine-tuned to the negative direction of the Y-axis, the actual distance is shortened to 35mm, the box cover is moved 5mm along the positive direction of the Y-axis again, and the final actual distance is 30mm, which meets the preset safe welding distance requirement;

[0119] The welding point position is in the perpendicular direction of the movement direction, the X-axis direction deviation, the current position of the box cover is (1010.0, 1030.0, 501.1), the actual distance is calculated as 29.8mm, which is approximately equal to 30mm, but the X-axis deviation is 11.3mm, which is perpendicular to the movement direction, resulting in a deviation of the groove alignment, the relative position of the welding point position and the mobile welding piece has X-axis perpendicular direction deviation, the full rotation mode is adopted, the box cover is rotated clockwise by 2° around the Z-axis, the full rotation angle, the X-axis deviation is corrected from 11.3mm to 0.5mm within the allowable range, at this time the actual distance still maintains 30mm, without adjusting the movement amount, directly entering the docking process;

[0120] The rotation mode cannot be adjusted, the box cover position is (1020.0, 1080.0, 510.0), the X-axis deviation is 21.3mm, the Z-axis deviation is 8.9mm, the actual distance is 81mm, and the rotation angle exceeds the limit, the maximum rotation angle of the device is ±5°, which cannot be corrected, the translation position of the moving welding part is adjusted, the box cover is controlled to move 20mm in the negative direction of the X-axis and 8mm in the negative direction of the Z-axis, the translation position is (1000.0, 1080.0, 502.0), the actual distance after translation is calculated as 77.72mm, and the box cover is further adjusted by rotating 2° around the X-axis through the front rotation mode. Due to rotation, the edge of the box cover is about 3.49mm close to the negative direction of the Y-axis, and the actual distance is about 77.72-3.49=74.23mm at this time. Finally, the box cover is controlled to move 44.23mm in the negative direction of the Y-axis, and the final box cover position reaches the appropriate position, with an actual distance of 30mm, meeting the requirements.

[0121] By comparing the actual distance with the preset safe welding distance, a clear adjustment logic is formed, ensuring that the moving welding part and the welding point are always in a safe and appropriate relative position, avoiding the risk of collision caused by too close distance, and preventing low efficiency caused by too far distance. For deviations in different directions, the front rotation mode and the full rotation mode are flexibly used to achieve precise adaptation to position deviation. The front rotation mode is used for deviation in the same direction of the moving direction, which efficiently shortens the distance by adjusting the pitch angle, ensuring the accuracy of position calibration along the conveying direction. The full rotation mode focuses on the deviation in the vertical direction, and the offset is corrected by horizontal twisting, ensuring the accuracy of the groove alignment. The targeted application of the two rotation modes improves the efficiency and accuracy of position adjustment. When the rotation mode is limited, the translation position of the moving welding part is adjusted for adaptation, forming a complete adjustment closed loop, avoiding adjustment stagnation caused by equipment limitations, and ensuring that the actual distance meets the preset requirements regardless of the type and size of the deviation. The whole process of adaptive adjustment from distance judgment to deviation correction is realized, which not only ensures the safety of welding operation, but also improves the accuracy of welding point docking, providing reliable protection for the stable operation of subsequent welding processes.

[0122] Specifically, the process of determining the clamping position based on the rotation mode and the position of the welding point in the target welding area includes,

[0123] Based on the position of the welding point in the target welding area, the clamping position is determined by excluding non-clamping surfaces and continuing to determine the position of the welding point;

[0124] Wherein, the non-clamping surface is a curved welding surface of the welding part; the position of the continuing welding point is the position of the point to be welded after the welding of the current welding point is completed.

[0125] Non-plane feature, there are two arc-shaped protrusions in the middle of the box cover with a curvature radius of 50mm, which belong to non-plane with curvature; the edge bevel area with a width of 20mm is also excluded from the clamping range because it needs to be welded, the clamping position of the front rotary motion around the X-axis needs to avoid the area near the rotary shaft, and ensure that the box cover is balanced when rotating;

[0126] The current welding point W10 is located at the midpoint of the front edge of the box cover, and the subsequent welding points W11, W12, and W13 are distributed along the front edge in sequence, with W11 being 100mm to the right of W10, W12 being 100mm to the right of W11, and W13 being 100mm to the right of W12; the target welding area is a 20mm wide bevel area on the front edge of the box cover, and the clamping position needs to be at least 50mm away from this area to avoid blocking the welding path;

[0127] Identify the non-plane surface of the box cover, the coordinate range of the middle arc-shaped protrusion area is X: 500-700mm, Y: 400-600mm, because it has curvature, it is easy to slip when clamping, so it is directly excluded; the bevel edge area with a width of 20mm where all welding points are located is excluded from clamping to avoid damaging the bevel or affecting welding.

[0128] Continue the welding points W11-W13 to the right of W10, and the 50mm range around them is X: 1098.7-1398.7mm, Y: 1002.3-1052.3mm, which needs to be reserved for welding operation space, excluded from clamping to prevent interference between the mechanical arm and the clamping jaw during subsequent welding;

[0129] The front rotary motion around the X-axis requires that the clamping positions be symmetrically distributed on both sides of the rotary shaft along the X-axis along the length of the box cover, Y=550mm, and the distance from the rotary shaft be greater than or equal to 300mm to ensure stable rotary torque, from the remaining available areas including flat, no curvature, and away from the welding and subsequent welding points,

[0130] Select 2 symmetric clamping points:

[0131] Clamping point A=(300,300,501.1) is located in the middle of the left side of the box cover, which is flat and has no curvature, and is greater than or equal to 300mm from W10 and the subsequent welding points;

[0132] Clamping point B=(1300,300,501.1) is located in the middle of the right side of the box cover, which is symmetric about the X-axis with point A, meeting the force balance requirements of the front rotary motion.

[0133] The clamping points A and B avoid the non-clamping surface and continue to the waiting welding point area, which is 80 mm away from the target welding area, and does not affect the welding path. When the box cover is clamped at these two positions and rotated 2° around the X axis, there is no slipping or interference phenomenon. After rotation, the W10 point is accurately aligned with the box groove, meeting the welding preparation requirements. During subsequent welding of W11-W13, the clamping jaw does not need to be repositioned, as the operation space has been reserved, and the welding point can be directly switched, improving the process efficiency.

[0134] By accurately identifying the position of the welding point in the target welding area and combining the rotation mode requirements, the non-clamping surface and the continued waiting welding point area are scientifically excluded, effectively ensuring the rationality and safety of the clamping position. Excluding the non-clamping surface with curvature can avoid slipping during clamping, ensure stable clamping of the welded piece, reduce positional deviation caused by unstable clamping, and provide a basis for the accuracy of subsequent welding operations. Excluding the continued waiting welding point and its surrounding area reserves sufficient welding operation space, effectively preventing interference between the mechanical arm and the clamping jaw during subsequent welding, ensuring smooth welding process, and reducing unnecessary adjustment time. In combination with the special requirements of the rotation mode for the clamping position, such as symmetrical distribution on both sides of the rotation axis and maintaining a certain distance during the front rotation, the clamping position can adapt to the rotation requirements, ensuring balanced force on the welded piece during rotation, avoiding deformation or positional deviation of the welded piece due to uneven force, and ensuring accurate alignment of the welding point after rotation, improving the quality of welding preparation. Reasonable clamping position does not need to be repositioned during subsequent welding point switching, significantly improving the efficiency of the overall welding process and reducing time loss caused by repeated operations, providing strong support for large-scale production.

[0135] Specifically, the process of detecting the actual groove angle and the butt joint gap of the butt joint position includes,

[0136] Based on the condition that the comparison result of the groove angle is unqualified and the comparison result of the butt joint gap is qualified, the rotation angle is adjusted to make the actual groove angle qualified;

[0137] Based on the condition that the comparison result of the groove angle is qualified and the comparison result of the butt joint gap is unqualified, the movement amount of the welded piece in the direction perpendicular to the welding direction is adjusted to make the butt joint gap qualified;

[0138] Based on the condition that the comparison result of the groove angle is unqualified and the comparison result of the butt joint gap is unqualified, the rotation angle is first adjusted to make the actual groove angle qualified, and then the movement amount is adjusted to make the butt joint gap qualified;

[0139] Wherein, the comparison result of the groove angle is the comparison result of the actual groove angle and the standard groove angle; the comparison result of the butt joint gap is the comparison result of the butt joint gap and the standard gap; the welding direction refers to the direction perpendicular to the butt joint edge.

[0140] The actual groove angle and the butt joint gap are detected by using a laser profile sensor, the rotation angle is adjusted by full rotation of the box cover around the Z axis, and the moving amount is adjusted by moving the box cover along the Y axis perpendicular to the welding direction, because the welding direction is the negative direction of the X axis and the vertical direction is the Y axis translation. In this embodiment, the standard groove angle is set to 60°, and the standard gap is 2mm,

[0141] The groove angle is unqualified, and the butt joint gap is qualified,

[0142] The actual groove angle is 55°, and the butt joint gap is 2.0mm;

[0143] Deviation reason: the box cover is rotated counterclockwise around the Z axis by 2.5°, resulting in a smaller groove angle on both sides,

[0144] Adjustment steps: control the box cover to rotate clockwise around the Z axis by 2.5° full rotation angle, so that the groove on both sides is reopened to 60°;

[0145] Again, the actual groove angle is 60°, and the butt joint gap is still 2.0mm, because the rotation axis passes through the top point of the groove, and the gap is not affected.

[0146] The groove angle is qualified, and the butt joint gap is unqualified,

[0147] Detection results: the actual groove angle is 60°, and the butt joint gap is 3.5mm;

[0148] Deviation reason: the box cover deviates from the box body by 0.75mm along the positive direction of the Y axis, and the translation deviation perpendicular to the welding direction causes the gap to increase,

[0149] Adjustment steps: calculate the moving amount, according to the geometric relationship, for every 1mm increase in butt joint gap, 0.5mm needs to be moved along the negative direction of the Y axis, which is perpendicular to the welding direction, so the moving amount is (3.5-2.0) x 0.5 = 0.75mm, and the box cover is controlled to move 0.75mm along the negative direction of the Y axis,

[0150] Again, the butt joint gap is 2.0mm, and the groove angle is still 60°, and the translation does not affect the angle.

[0151] The groove angle and the butt joint gap are both unqualified,

[0152] Detection results: the actual groove angle is 53°, and the butt joint gap is 1.0mm,

[0153] Deviation reason: the box cover is rotated counterclockwise around the Z axis by 3.5°, resulting in a smaller angle, and at the same time, the box cover is offset by 0.5mm along the negative direction of the Y axis, resulting in a smaller gap,

[0154] Adjustment steps:

[0155] First step angle adjustment: control the box cover to rotate 3.5° clockwise around the Z axis, so that the actual groove angle returns to 60°, at this time, due to the rotation driving the box cover to translate slightly, the butt joint gap becomes 1.2mm

[0156] Second step gap adjustment: calculate the amount of movement along the positive direction of the Y axis (2.0-1.2) x 0.5=0.4mm,

[0157] Control the box cover to translate 0.4mm along the positive direction of the Y axis, and detect the butt joint gap again, which is 2.0mm, and the groove angle is 60°.

[0158] Through targeted adjustment strategy, the precision control of the butt joint precision of the welded part is realized, which has significant practical value. For the case that the groove angle is unqualified but the butt joint gap is qualified, by adjusting the rotation angle for correction, the groove angle can be quickly qualified without affecting the qualified gap, which ensures that the fitting angle of the welding surface meets the process requirements, and creates conditions for the uniform formation of the molten pool during subsequent welding. When the groove angle is qualified and the butt joint gap is unqualified, only the movement perpendicular to the welding direction is adjusted, which can accurately eliminate the gap deviation while maintaining the correct angle, avoiding new deviations that may be caused by adjusting the angle, and ensuring the accuracy of the gap size, which is beneficial to control the welding material filling amount and the welding seam forming quality. For the case that both are unqualified, the step-by-step strategy of adjusting the angle first and then adjusting the gap is adopted, which effectively avoids the mutual interference in the adjustment process, ensures that the groove angle, a key parameter affecting the welding strength, is qualified first, and ensures the sealing performance of the welding through subsequent gap adjustment, so that the final butt joint state fully meets the process standard. The adjustment mode considering different situations takes into account the efficiency and accuracy, and can flexibly cope with different types of butt joint deviations, significantly improving the quality stability of the transformer oil tank welding, and providing reliable support for ensuring the structural strength and sealing performance of the oil tank.

[0159] Specifically, the process of detecting the weld angle inclination of the welded part includes,

[0160] Detecting the weld angle inclination on the plane perpendicular to the center line of the welding angle based on the weld angle inclination to determine the welding angle;

[0161] Wherein, the weld angle inclination is the included angle between the plane where the center line of the welding angle is located and the plane where the welding surface is located.

[0162] Please refer to Figure 4 , which is the process flow chart of determining the welding angle in the automatic welding method for the transformer oil tank production line in the embodiment; Figure 4

[0163] Specifically, the process of determining the welding angle based on the weld angle inclination includes, ​

[0164] comparing the weld angle inclination with an inclination threshold value;

[0165] based on the weld angle inclination being less than or equal to the inclination threshold value, determining the current welding angle as the final welding angle;

[0166] based on the weld angle inclination being greater than the inclination threshold value, calculating a compensation angle according to the weld angle inclination, and adjusting the welding angle of the welding mechanism so that the compensated welding angle is perpendicular to the plane in which the welding surface lies;

[0167] wherein the inclination threshold value is set according to the sealing and strength requirements of the transformer tank welding, and the compensation angle is equal to the difference between the weld angle inclination and the inclination threshold value.

[0168] In this embodiment, the inclination threshold value is set to 3° according to the sealing requirements of the tank;

[0169] The laser line scanning sensor detects the plane perpendicular to the center line of the welding angle, i.e. along the Y-Z plane. Due to the angle deviation of the welding angle center line along the X-axis direction, the welding torch can be rotated around the X-axis to adjust the pitch angle, compensate for the weld angle inclination, and ensure that the welding torch axis is perpendicular to the welding surface,

[0170] The center line of the welding angle is consistent with the welding direction along the X-axis direction, which is the theoretical symmetry axis of the weld. The plane perpendicular to the center line is the Y-Z vertical plane, which is used to detect the inclination of the weld in the vertical direction

[0171] The plane in which the welding surface lies is the 90° included angle plane formed by the X-Z plane of the tank front wall and the X-Y plane of the tank cover top surface. In the ideal state, the weld should be distributed along the angle bisector of this plane,

[0172] The weld angle inclination is the included angle between the actual weld in the Y-Z plane and the plane in which the welding surface lies, i.e. the angle by which the weld deviates from the ideal angle bisector,

[0173] The laser line scanning sensor emits a laser beam and scans the weld area along the Y-Z plane to obtain the weld cross-sectional profile data. Through image processing, the projection of the actual weld center line in the Y-Z plane is extracted and compared with the ideal angle bisector of the plane in which the welding surface lies, and the included angle difference is calculated,

[0174] For example: after scanning, it is found that the actual weld center line in the Y-Z plane is inclined upward and forms an included angle of 2.5° with the ideal angle bisector, so the weld angle inclination is 2.5°,

[0175] The weld angle inclination 2.5 is less than 3°, the inclination is within the allowable range, the current welding angle does not need to be adjusted, the weld forming quality can be ensured, the current welding angle is preset as 45° perpendicular to the ideal welding surface as the final welding angle, the welding gun is welded at 45°, the weld metal uniformly fills the V-shaped groove, the forming is smooth, and the sealing requirement is met;

[0176] The weld angle inclination 4.2° is greater than 3°, the inclination direction is upward in the Y-Z plane, there is a slight pitch deviation when the tank cover is butt-jointed, the actual plane of the welding surface and the ideal plane form an inclination of 4.2°,

[0177] The compensation angle = the weld angle inclination - the inclination threshold = 4.2°-3° = 1.2°

[0178] Adjust the welding mechanism: control the welding gun to rotate upward 1.2° around the X axis, which is consistent with the inclination direction, so that the compensated welding angle is 45°+1.2° = 46.2°, and the welding gun axis is perpendicular to the plane where the actual welding surface is located at an angle of 46.2°, which just offsets the 4.2° inclination.

[0179] By accurately detecting the weld angle inclination and adjusting the welding angle accordingly, a reliable support is provided for ensuring the welding quality. With the detection of the laser line scanning sensor in a specific plane, the inclination degree of the weld deviating from the ideal state can be accurately captured, and combined with the setting of the inclination threshold, a scientific judgment of whether the welding angle needs to be adjusted can be realized. When the inclination is within the allowable range, the current welding angle is directly used, which simplifies the operation process while ensuring the stability of the weld forming; when the inclination exceeds the limit, the compensation angle is calculated and the welding mechanism is adjusted, so that the welding gun is always perpendicular to the actual welding surface, effectively avoiding problems such as uneven depth of weld on both sides and poor forming caused by angle deviation. It can adapt to the slight pitch deviation when the welding parts are butt-jointed, and meet the strict requirements of the transformer oil tank on the weld sealing and structural strength, reduce the quality hidden danger such as leakage, and improve the stability and reliability of the welding process, which provides a strong guarantee for the safety of subsequent use.

[0180] The embodiment also provides an automatic welding control system for a transformer oil tank production line, comprising,

[0181] An image acquisition module is used to acquire a three-dimensional image of the positioned welding part;

[0182] A welding point position module is connected with the image acquisition module, and is used to compare the three-dimensional image with a preset three-dimensional image to determine the position of the welding point in the target welding area;

[0183] A path planning module is connected with the welding point position module, and is used to calculate a welding point vector according to the target welding area position and the direction of the moving welding part;

[0184] an execution module connected with the path planning module, configured to control the robot arm to butt joint the positioning welding piece and the moving welding piece according to the determined rotating mode and the clamping position;

[0185] a parameter detection adjustment module connected with the execution module, configured to detect the actual bevel angle and the butt joint gap of the butt joint position, and output a rotating angle adjustment instruction or a moving amount adjustment instruction to the butt joint execution module;

[0186] a welding angle determination module connected with the parameter detection adjustment module, configured to detect the inclination of the welding angle, and calculate and output a welding angle adjustment instruction based on the inclination;

[0187] a main control module connected with the image acquisition module, the welding point position determination module, the path planning module, the execution module, the parameter detection adjustment module and the welding angle determination module respectively, and configured to coordinate the timing and logic of the welding process.

[0188] Please refer to Figure 6 , Figure 6 a schematic structural view of a welding device for the automatic welding method of the transformer oil tank production line in the embodiment;

[0189] a first rotating shaft 1 configured to rotate in the Z axis perpendicular to the welding surface;

[0190] a second rotating shaft 2 configured to rotate in the Y axis parallel to the welding surface;

[0191] a welding head 3 configured to position the welding piece and the moving welding piece for welding.

[0192] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

[0193] The above description is only for the preferred embodiments of the present application and is not used to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An automatic welding method for a transformer oil tank production line, characterized by, The method comprises the following steps: surrounding layout shooting based on several industrial cameras to obtain a stereoscopic three-dimensional image of a positioning welding piece, determining a welding point position in a target welding area based on the stereoscopic three-dimensional image and a preset three-dimensional image; determining a welding point position vector based on the target welding area position and the direction of the moving welding piece; determining a rotating mode based on the welding point position vector, and determining a clamping position based on the rotating mode and the position of the welding point in the target welding area, wherein the clamping position is determined by excluding a non-clamping surface and a continued welding point position based on the position of the welding point in the target welding area, the non-clamping surface is a curved welding surface of the welding piece, and the continued welding point position is a point position that needs to be welded after the welding of the current welding point position is completed; based on the rotating mode and the clamping position of the positioning welding piece, abutting the positioning welding piece and the moving welding piece to determine a welding point position, detecting an actual bevel angle and an abutting gap of the abutting position, and adjusting the rotating angle of the moving welding piece and the moving amount of the moving welding piece based on the actual bevel angle and the abutting gap; based on the abutted welding piece, detecting a welding seam angle inclination, and determining a welding angle based on the welding seam angle inclination; wherein the rotating mode comprises a full rotation mode and a front rotation mode, the full rotation mode is a rotating mode of the positioning welding piece with a first rotating shaft, and the front rotation mode is a rotating mode with a second rotating shaft, the first rotating shaft is a Z-axis perpendicular to the welding surface, and the second rotating shaft is an X-axis parallel to the welding surface, and the X-axis coincides with the moving direction of the moving welding piece.

2. The method for automatic welding of transformer oil tank production line as claimed in claim 1 wherein, The process of determining the welding point position in the target welding area based on the stereoscopic three-dimensional image and the preset three-dimensional image comprises: recognizing and extracting the actual physical coordinates of the welding point position based on the stereoscopic three-dimensional image; comparing the actual physical coordinates with the standard position of the target welding area in the preset three-dimensional image to determine the specific positioning of the welding point position in the target welding area, and obtaining the target calibration position of the welding point position in the target welding area.

3. The method for automatic welding of transformer tank production line as claimed in claim 2 wherein, The process of determining the welding point position vector based on the target welding area position and the direction of the moving welding piece comprises: calculating the actual distance of the welding point position vector based on the target calibration position and the position of the moving welding piece, comparing the actual distance with a preset safe welding distance to obtain a distance comparison result, and determining the rotating mode based on the distance comparison result; wherein the preset safe welding distance is a threshold value of the preset welding point position vector module length.

4. The method for automatic welding of transformer tank production line as claimed in claim 3 wherein, The process of determining the rotating mode based on the distance comparison result comprises: determining the rotating mode based on the welding point position vector based on the actual distance being greater than the preset safe welding distance; maintaining the current relative position state of the moving welding piece and the welding point position based on the actual distance being less than or equal to the preset safe welding distance.

5. The method for automatic welding of transformer tank production line as claimed in claim 4 wherein, The process of abutting the positioning welding piece and the moving welding piece based on the rotating mode and the clamping position of the positioning welding piece to determine the welding point position comprises: adjusting the welding point position by the front rotation mode based on the same direction of the welding point position in the moving direction of the moving welding piece. The welding point position is adjusted by full rotation in a direction perpendicular to the moving direction of the moving welding piece based on the welding point position; If the welding point position cannot be adjusted by rotation, the translation position of the moving welding piece is adjusted to adapt to the welding point position.

6. The method for automatic welding of transformer tank production line as claimed in claim 5 wherein, The process of detecting the actual bevel angle and the butt joint gap of the butt joint position includes, If the bevel angle comparison result is unqualified and the butt joint gap comparison result is qualified, the rotation angle is adjusted to make the actual bevel angle qualified; If the bevel angle comparison result is qualified and the butt joint gap comparison result is unqualified, the movement amount of the moving welding piece in the direction perpendicular to the welding direction is adjusted to make the butt joint gap qualified; If the bevel angle comparison result is unqualified and the butt joint gap comparison result is unqualified, the rotation angle is first adjusted to make the actual bevel angle qualified, and then the movement amount is adjusted to make the butt joint gap qualified; The bevel angle comparison result is the comparison result of the actual bevel angle and the standard bevel angle; the butt joint gap comparison result is the comparison result of the butt joint gap and the standard gap; the welding direction refers to the direction perpendicular to the butt joint edge.

7. The method for automatic welding of transformer tank production line as claimed in claim 6 wherein, The process of detecting the weld angle inclination of the welding piece includes, The weld angle inclination is detected on the plane perpendicular to the center line of the welding angle, and the welding angle is determined based on the weld angle inclination; The weld angle inclination is the included angle between the plane where the center line of the welding angle is located and the plane where the welding surface is located.

8. The method for automatic welding of transformer oil tank production line as claimed in claim 7 wherein, The process of determining the welding angle based on the weld angle inclination includes, The weld angle inclination is compared with the inclination threshold value; If the weld angle inclination is less than or equal to the inclination threshold value, the current welding angle is determined as the final welding angle; If the weld angle inclination is greater than the inclination threshold value, a compensation angle is calculated according to the weld angle inclination, and the welding angle of the welding mechanism is adjusted so that the compensated welding angle is perpendicular to the plane where the welding surface is located; The inclination threshold value is set according to the sealing and strength requirements of the transformer tank welding, and the compensation angle is equal to the difference between the weld angle inclination and the inclination threshold value.

9. An automatic welding control system for a transformer tank production line, which applies the automatic welding method for a transformer tank production line according to any one of claims 1 to 8, characterized by, It includes, An image acquisition module is used to collect a three-dimensional image of the positioning welding piece; A welding point position module is connected with the image acquisition module to compare the three-dimensional image with a preset three-dimensional image and determine the position of the welding point in the target welding area; A path planning module is connected with the welding point position module to calculate a welding point vector according to the target welding area position and the moving welding piece direction; An execution module is connected with the path planning module to control the mechanical arm to butt joint the positioning welding piece and the moving welding piece according to the determined rotation mode and clamping position; A parameter detection and adjustment module is connected with the execution module to detect the actual bevel angle and the butt joint gap of the butt joint position and output a rotation angle adjustment instruction or a movement amount adjustment instruction to the butt joint execution module; A welding angle determination module is connected with the parameter detection and adjustment module to detect the weld angle inclination and calculate and output a welding angle adjustment instruction based on the inclination. A main control module is connected with the image acquisition module, the welding point position positioning module, the path planning module, the execution module, the parameter detection and adjustment module and the welding angle determination module respectively, and coordinates the time sequence and logic of the welding process.

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