A welding system and method for welding a flange web

Abstract

The present application relates to the technical field of welding equipment and welding process, and discloses a flange web plate welding system and a welding method, which comprises a support displacement mechanism, a first welding robot and a second welding robot fixedly arranged on the outer sides of the two ends of a tower pole respectively, a web plate automatic positioning device, a visual measurement system and a control system. The control system performs a three-stage welding process: in the first welding stage, all the web plates are completed in a batch symmetrical manner; in the second welding stage, intermittent annular welds are completed; in the third welding stage, before welding continuous annular welds, the root gap distribution is scanned by a weld tracking sensor, and a variable parameter welding strategy is dynamically generated according to the gap distribution to realize variable gap adaptive welding. The present application solves the problem of difficult manual positioning of the web plate, realizes full-circle welding in a half-circle working space, effectively controls welding deformation, and significantly improves welding quality and production efficiency.

Description

Technical Field

[0001] This invention relates to the field of welding equipment and welding process technology, and in particular to a welding system and welding method for flange stiffeners. Background Technology

[0002] In the manufacturing process of power transmission steel pipe towers, the welding of the tower end flanges and stiffening plates is a crucial step in ensuring the structural strength and assembly precision of the tower. Traditional processes mainly rely on manual arc welding, which suffers from low welding efficiency, poor quality stability, and high labor intensity for workers. With the development of automation technology, some companies have begun to introduce welding robots for automated welding.

[0003] In the prior art, Chinese invention patent application No. 202110336766.7 discloses an automatic welding device and method for flange ribs of power poles. This solution uses two welding robots that can move along a track, in conjunction with a roller frame and a vision sensing system, to achieve automatic welding of the ribs and flange welds. However, this solution still has the following shortcomings: First, welding robots need to be mounted on mobile carts and have long tracks laid, resulting in high equipment costs and large space requirements. Furthermore, the control precision and repeatability of the robot's moving axes are lower than those of fixed installations, potentially leading to positional deviations after long-term operation.

[0004] Second, the welding sequence of this scheme is "welding one by one," meaning that after welding all the welds of one stiffener, the workpiece is rotated to the position of the next stiffener, and then all the welds of the next stiffener are welded. This localized continuous welding method is prone to heat concentration, causing flange angle deformation and affecting flatness.

[0005] Third, the vision system in this scheme is only used for weld positioning (identifying the spatial location of the weld) and does not involve dynamically adjusting welding parameters according to changes in weld gap, which is insufficient for adapting to variable gap conditions.

[0006] Fourth, in the pre-welding stiffener positioning stage, four stiffeners need to be positioned at 0°, 90°, 180°, and 270° around the flange circumference to determine the distribution of the remaining stiffeners. Traditionally, this requires manual alignment of the four stiffeners with the flange and tower rod, followed by spot welding. Due to the narrow space at the tower rod end and the inconvenient operation in the angled area between the flange and tower rod, manual positioning makes it difficult to simultaneously ensure a double fit between the stiffeners and the flange end face and the tower rod surface. Positioning accuracy relies heavily on operational experience, resulting in poor consistency. Furthermore, existing fixtures are ill-suited for flanges and tower rods of different diameters, requiring readjustment each time a product is changed, leading to low efficiency.

[0007] Furthermore, the towers of power transmission steel pipe towers are typically constructed by bending and welding steel plates, resulting in regular polygonal end faces (such as dodecagons, hexagons, etc.), while the flanges are circular. When assembling the polygonal end faces with the circular flanges, the inner circle of the flange needs to be trimmed. However, there is an inherent geometric mismatch between the two: the polygonal vertices fit tightly (small gap), while the midpoints of the polygonal sides have larger gaps (large gap). This periodic gap variation, coupled with processing errors and potential misalignment issues during assembly, results in a complex and uneven distribution of the circumferential weld root gap between the flange and the tower. Additionally, in actual assembly, the flange is not flush with the tower end face; instead, it is offset outwards by a certain distance (approximately 2-5 mm) using the flange's own thickness, forming a small step to facilitate welding operations and stress transition. This further increases the complexity of the gap distribution.

[0008] Therefore, existing technologies still lack a tower flange stiffener welding system and process that can achieve automatic stiffener positioning, adapt to the semi-circular working space, optimize welding sequence to control deformation, and realize adaptive welding with variable gap. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a flange stiffener welding system and welding method that can realize automatic positioning of stiffeners, adapt to the semi-circular working space, optimize the welding sequence to control deformation, and realize variable gap adaptive welding.

[0010] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A welding system for flange stiffeners includes a tower, a flange at the end of the tower, and stiffeners circumferentially distributed between the flange and the tower; a support and displacement mechanism including an active roller frame and a driven roller frame for supporting and driving the tower to rotate indexably around its axis; a first welding robot and a second welding robot, respectively fixedly disposed on the outer sides of both ends of the tower; an automatic stiffener positioning device disposed on the outer side of the end of the flange for synchronously closing at least four stiffeners radially to fit against the surface of the tower; a weld tracking sensor for acquiring circumferential distribution data of the weld root gap; a vision measurement system for measuring the dimensions of the flange or the tower; and a control system electrically connected to the support and displacement mechanism, the first welding robot, the second welding robot, the automatic stiffener positioning device, the weld tracking sensor, and the vision measurement system. The automatic stiffener positioning device is configured to: based on the measurement results of the vision measurement system, bring the stiffeners together radially to fit the surface of the tower rod; The control system is configured to perform the following welding processes: (a) First welding stage: Control the first welding robot and the second welding robot in their respective workspaces to weld the same type of weld on all visible stiffening plates on their corresponding end flanges; then control the support displacement mechanism to rotate the tower 180 degrees and weld the same type of weld on the remaining stiffening plates; repeat this process to complete all types of welds on all stiffening plates in sequence. (b) Second welding stage: Referring to the indexing rotation method in step (a), complete the discontinuous circumferential weld between the flange and the tower; (c) Third welding stage: Before welding the continuous circumferential weld between the flange and the tower, the weld is first scanned around the weld using a weld tracking sensor to obtain the distribution data of the root gap along the circumferential direction. Based on the distribution data, a welding parameter set associated with the circumferential position is dynamically generated. Then, during the welding process, the corresponding welding parameter set is called according to the real-time position to perform variable parameter adaptive welding.

[0011] This invention discloses a welding system for flange stiffeners, wherein the welds of the stiffeners include: a first fillet weld A between the stiffener and the flange, a second fillet weld B between the stiffener and the flange, a first fillet weld C between the stiffener and the tower, and a second fillet weld D between the stiffener and the tower. The welding sequence is as follows: first, complete all the first fillet welds A between the stiffeners and the flange; then, complete all the second fillet welds B between the stiffeners and the flange; then, complete all the first fillet welds C between the stiffeners and the tower; and finally, complete all the second fillet welds D between the stiffeners and the tower.

[0012] The present invention discloses a welding system for flange stiffeners, wherein the weld tracking sensor is a laser displacement sensor installed at the end of the first welding robot and the second welding robot. The distance from the sensor to the tower surface or the edge of the flange is measured in real time by triangulation, thereby calculating the weld root gap.

[0013] The present invention discloses a welding system for flange stiffeners, wherein the welding parameter set includes at least one of welding torch oscillation amplitude, welding speed, wire feed speed, welding current and welding voltage; the control system divides the circumferential direction into multiple intervals according to the size of the root gap value, and matches a corresponding welding parameter set for each interval.

[0014] The present invention discloses a welding system for flange stiffeners, wherein a first welding robot is mounted on a first cantilever of a first column, the first column being fixed to the ground; a second welding robot is mounted on a second cantilever of a second column, the bottom of the second column being equipped with a walking motor that can move along a walking track; the first and second cantilever arms can move up and down.

[0015] The present invention discloses a welding system for flange stiffeners, wherein the active roller frame drives the tower and the driven roller frame to move on the traveling track via a motor-driven chain.

[0016] The present invention discloses a welding method for flange stiffeners, comprising the following steps: S1: Install the automatic positioning device for the stiffener plates on the outer side of the flange end. With the four positioning stiffener plates in the open state, hoist the tower and flange onto the active roller frame and the driven roller frame. S2: The visual measurement system measures the dimensions of the flange or tower. The control system controls the automatic positioning device of the stiffener plate to bring the four positioning stiffener plates together radially to fit the surface of the tower, and then spot welds the four positioning stiffener plates to fix them. S3: Disassemble the automatic positioning device for stiffeners and spot weld the remaining stiffeners; S4: First welding stage: Control the first and second welding robots in their workspaces to weld the same type of weld on all visible stiffening plates on their respective end flanges; control the tower to rotate 180 degrees and weld the same type of weld on the remaining stiffening plates; repeat until all types of welds on all stiffening plates are completed. S5: Second welding stage: Referring to the indexing rotation method in step S4, complete the intermittent circumferential weld E between the flange and the tower; S6: Third welding stage: Before welding the continuous circumferential weld F, the weld is scanned around the weld using a weld tracking sensor to obtain the distribution data of the root gap along the circumferential direction; a welding parameter set associated with the circumferential position is generated based on the distribution data; then, during the welding process, the corresponding welding parameter set is called according to the real-time position to perform variable parameter adaptive welding.

[0017] The present invention discloses a welding method for flange stiffeners, wherein in step S4, the welding sequence of the stiffener welds is as follows: first weld the first fillet weld A of all stiffeners to the flange, then weld the second fillet weld B of all stiffeners to the flange, then weld the first fillet weld C of all stiffeners to the tower, and finally weld the second fillet weld D of all stiffeners to the tower.

[0018] The present invention discloses a welding method for flange stiffeners, wherein in step S6, the distribution data of the root gap is obtained by a laser displacement sensor. The sensor emits a laser beam toward the weld position and receives the reflected light. The distance from the sensor to the tower surface is measured in real time by the triangulation method. Since the end face of the tower is a regular polygon, the measured distance value exhibits periodic fluctuations. The root gap is obtained by calculating the difference between the measured distance and the theoretical distance.

[0019] The present invention discloses a welding method for flange stiffeners, wherein in step S2, four stiffeners are first spot-welded to the flange at positions of 0°, 90°, 180°, and 270°, and then the remaining stiffeners are spot-welded.

[0020] The welding system and welding method for flange stiffeners of this invention differ from existing technologies in that: 1. Automatic positioning of stiffening plates improves efficiency and accuracy: By combining a vision measurement system with an automatic stiffening plate positioning device, the closing position of the four positioning stiffening plates is automatically determined according to the actual size of the flange or tower. This solves the problems of inconvenience for manual operation in narrow spaces and difficulty in ensuring positioning accuracy, and enables rapid adaptation to towers of different diameters.

[0021] 2. Low equipment cost and simple control: The robot is fixedly installed and does not require a seventh axis walking mechanism or long-distance track. It can complete full-circumference welding simply by rotating the workpiece indexing, which greatly reduces equipment investment and programming difficulty and saves factory space.

[0022] 3. Excellent control of welding deformation: The "batch symmetrical welding" strategy is adopted, that is, all stiffeners of the same type of weld are welded uniformly first, and then the next type of weld is welded uniformly. This makes the heat evenly distributed on the entire flange and avoids heat concentration and angular deformation caused by local continuous welding.

[0023] 4. The three-stage welding sequence is scientific and reasonable: First, weld the stiffening plate weld, using the stiffening plate as a reinforcing rib to initially constrain the relative position of the flange and the tower, providing rigid fixation; then weld the intermittent circumferential weld, gradually filling the root and releasing thermal stress; finally, weld the continuous circumferential weld to ensure overall sealing.

[0024] 5. Variable gap adaptive welding ensures quality: To address the geometric mismatch between the polygonal tower end face and the circular flange, as well as the complex gap distribution caused by assembly misalignment, a pre-weld laser scanning + variable parameter strategy is adopted to achieve precise filling as the position changes, significantly improving the first-pass yield of welding.

[0025] The welding system and welding method for a flange stiffener of the present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0026] Figure 1 This is an isometric drawing of a flange stiffener welding system; Figure 2 yes Figure 1 A partial structural schematic diagram of a welding system for flange stiffeners is shown. Figure 3 This is a schematic diagram showing the front view of the weld. Figure 4 This is a schematic diagram showing the side position of the weld. Figure 5 This is an isometric drawing of the automatic ribbed positioning device; Figure 6 yes Figure 5 Side view; Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0027] In the diagram: 1. Tower; 2. Flange; 3. Rib plate; 4. Active roller frame; 401. First roller; 5. Driven roller frame; 501. Second roller; 6. Walking rail; 7. First welding robot; 8. Second welding robot; 9. Weld seam tracking sensor; 10. First column; 11. First cantilever; 12. Second column; 13. Second cantilever; 14. Walking motor; 15. Cross; 16. Guide rail; 17. Slider; 18. Clamping component; 19. Ring; 20. Spiral guide groove; 21. Guide pin; 22. Drive motor. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1 I. Overall Structure like Figures 1-7 As shown, a welding system for flange stiffeners is used to weld the flange 2 at the end of the tower 1 and the stiffeners 3 circumferentially distributed between the flange 2 and the tower 1.

[0030] The system consists of the following components: first column 10, first cantilever 11, first welding robot 7, second column 12, second cantilever 13, second column walking motor 14, walking rail 6, active roller frame 4, driven roller frame 5, stiffener plate automatic positioning device, vision measurement system, weld seam tracking sensor 9, and control system.

[0031] II. Support Displacement Mechanism The active roller frame 4 and the driven roller frame 5 are used to support the tower 1. The active roller frame 4 is driven by a motor and a chain, which can drive the driven roller frame 5 and the tower 1 to move back and forth on the traveling rail 6, so as to achieve coarse adjustment of the overall position of the tower 1.

[0032] The active roller frame 4 is equipped with two first rollers 401, and the driven roller frame 5 is equipped with two second rollers 501. The first rollers 401 and second rollers 501 are used to clamp flanges 2 of different diameters. When the tower 1 is hoisted to the active roller frame 4 and the driven roller frame 5, the outer edge of the flange 2 is engaged between the first rollers 401 and the second rollers 501.

[0033] III. Welding Robots The first column 10 is fixed to the ground, and its first cantilever 11 supports the first welding robot 7, which is responsible for welding the stiffening plate 3 and circumferential weld of the left flange 2 of the tower 1. The second column 12 can move along the walking rail 6, and its second cantilever 13 supports the second welding robot 8, which is responsible for welding the stiffening plate 3 and circumferential weld of the right flange 2 of the tower 1. When the length of the tower 1 changes, the second column's walking motor 14 drives the second column 12 to move along the walking rail 6, adjusting the distance between the left and right robots.

[0034] The first welding robot 7 and the second welding robot 8 can move back and forth on the cantilever to weld the stiffening plates 3 at different radial positions on the same flange. When the diameter of the flange 2 changes, the cantilever can drive the welding robots to move up and down to adjust the welding height.

[0035] The first welding robot 7 and the second welding robot 8 are fixedly installed on the outer sides of both ends of the tower 1. Due to the limitation of the robot's arm span and the interference of surrounding equipment, the working space of a single robot can only cover an area of ​​about 180 degrees around the flange 2, that is, the semi-circular area in front of the robot's position.

[0036] IV. Automatic positioning device for stiffeners like Figure 5 , Figure 6 As shown, the automatic positioning device for the stiffeners is used to automatically close the four positioning stiffeners 3 (located at 0°, 90°, 180°, and 270° positions) to the surface of the tower rod 1 before welding, so as to facilitate spot welding positioning.

[0037] The purpose of this device is to determine the positions of the four positioning stiffeners 3 after the flange 2 is fitted onto the end of the tower rod 1, serving as a reference for the distribution of the remaining stiffeners 3. Traditional methods rely entirely on manual operation within the narrow space at the end of the tower rod 1, making it difficult to simultaneously ensure a double fit between the stiffeners 3 and the end face of the flange 2, as well as the surface of the tower rod 1. Furthermore, each product change requires readjustment of the clamps, resulting in low efficiency. This device achieves automatic alignment of the stiffeners through visual measurement and motor drive, requiring only manual spot welding to complete the positioning, significantly reducing operational difficulty. After the four positioning stiffeners 3 are spot welded, the device is immediately disassembled and removed without obstructing subsequent welding space. The remaining stiffeners 3 are still spot welded manually, achieving a reasonable division of labor: automated positioning and manual spot welding.

[0038] The specific structure of the automatic rib plate positioning device is as follows: The cross 15 is a cross-shaped frame, located on the outer side of the end of the flange 2, and coaxial with the flange 2. The cross 15 is fixedly installed on the ground or on a special support base and does not rotate with the ring 19. The four arms of the cross 15 extend in the directions of 0°, 90°, 180°, and 270° respectively.

[0039] Each of the four arms of the cross 15 is provided with a guide rail 16, which extends radially along the flange 2.

[0040] Each guide rail 16 is equipped with a slider 17, which can slide radially along the guide rail 16. The slider 17 is equipped with a clamping element 18 (such as a toggle clamp or bolt clamp) for clamping and fixing the stiffener plate 3. After the operator places the stiffener plate 3 into the positioning groove on the slider 17, they move the clamping element 18 to clamp the stiffener plate 3. After clamping, the bottom surface of the stiffener plate 3 (the surface that contacts the end face of the flange 2) remains in contact with the end face of the flange 2.

[0041] The ring 19 is rotatably mounted on one side of the cross 15 and is coaxial with the flange 2. The ring 19 is driven by the drive motor 22 and can rotate around its own axis. Four spiral guide grooves 20 are formed on the end face of the ring 19. The four spiral guide grooves 20 are evenly distributed circumferentially (corresponding to the four directions of 0°, 90°, 180° and 270° respectively), and each spiral guide groove 20 extends spirally from the outer end of the ring 19 towards the center.

[0042] Each slider 17 is fixed with a guide pin 21, one end of which extends into the corresponding spiral guide groove 20. When the ring 19 rotates, the groove wall of the spiral guide groove 20 pushes the guide pin 21 to move radially, and the guide pin 21 drives the slider 17 and the stiffener 3 to slide radially along the guide rail 16. The four stiffeners 3 synchronously close towards the center or open outward.

[0043] The drive motor 22 is a servo motor, mounted on the cross 15, and drives the ring 19 to rotate via gear transmission or a synchronous belt. The drive motor 22 is equipped with a brake that automatically locks when power is off, ensuring that the ring 19 remains in a locked position when not driven, and preventing the stiffener 3 from sliding on its own.

[0044] The ring 19 is made up of two half-rings connected by bolts and can be removed from the cross 15 after the four stiffeners 3 have been spot-welded.

[0045] V. Visual Measurement System The vision measurement system is used to measure the dimensions of flange 2 or tower 1, providing control basis for the automatic positioning device of stiffener plate.

[0046] The vision measurement system includes an industrial camera and a light source, mounted on the cross 15, facing the end face of the flange 2 or the surface of the tower 1. After the camera captures an image, the actual dimensions of the outer diameter of the flange 2 or the outer diameter of the tower 1 are extracted through image processing. The control system calculates the target position to which the stiffener 3 needs to be closed, and the target angle to which the ring 19 needs to be rotated, based on the actual dimensions.

[0047] VI. Control System and Welding Process The control system includes an industrial computer, a servo driver, a PLC, and a human-machine interface, which are electrically connected to the support positioning mechanism, the first welding robot 7, the second welding robot 8, the drive motor 22, the vision measurement system, and the weld seam tracking sensor 9, respectively.

[0048] The welding method is as follows: (a) Positioning Phase Step 1: Place the automatic rib plate positioning device on the outer side of the flange 2 end, making the cross 15 coaxial with the flange 2. Place the four positioning rib plates 3 into the positioning grooves of the four sliders 17 respectively, and clamp them by the clamping member 18. At this time, the four rib plates 3 are in the open state, and the guide pin 21 is located at the outermost end of the spiral guide groove 20.

[0049] Step 2: Hoist the tower 1 and flange 2 onto the active roller frame 4 and the driven roller frame 5, and insert the outer edge of the flange 2 between the first roller 401 and the second roller 501.

[0050] Step 3: The vision measurement system measures the dimensions of flange 2 or tower 1, and the control system calculates the target rotation angle of ring 19 based on the measurement results.

[0051] Step 4: The control system controls the drive motor 22 to drive the ring 19 to rotate to the target angle. The spiral guide groove 20 drives the four stiffeners 3 to converge towards the center synchronously through the guide pin 21 until the inner side of the stiffeners 3 is in contact with the surface of the tower rod 1.

[0052] Step 5: Manually spot weld the four positioning stiffeners 3 to fix them to the tower rod 1 and flange 2.

[0053] Step 6: Loosen the clamping part 18, remove the ring 19 (the two half rings are connected by bolts and can be quickly separated), and remove the entire automatic positioning device for the stiffener plate.

[0054] Step 7: Manually spot weld the remaining stiffeners 3 in the remaining areas (positions other than 0°, 90°, 180°, and 270°).

[0055] (II) First welding stage (stiffening plate weld) The stiffening plates 3 are triangular or trapezoidal in shape and are evenly distributed around the flange 2. Each stiffening plate 3 forms four fillet welds with the flange 2 and the tower 1 (e.g., Figure 5 (As shown): First fillet weld A between stiffening plate 3 and flange 2, second fillet weld B between stiffening plate 3 and flange 2, first fillet weld C between stiffening plate 3 and tower 1, second fillet weld D between stiffening plate 3 and tower 1.

[0056] First, the first welding robot 7 and the second welding robot 8 are controlled to simultaneously weld the first fillet weld A of all visible stiffener plates 3 on their respective end flanges within their respective 180-degree working spaces. After completing this half-turn, the active roller frame 4 drives the tower 1 to rotate precisely 180 degrees, allowing the other half of the stiffener plates 3 to enter the robot's working space, and the welding of the remaining stiffener plates 3's first fillet weld A continues. In this way, the first fillet weld A of all stiffener plates 3 is completed.

[0057] Subsequently, weld the remaining welds of all stiffening plates 3 in the same manner. That is: first, weld the second fillet welds B of all stiffening plates 3 in one go (rotating 180 degrees twice), then weld the first fillet welds C of all stiffening plates 3 in one go, and finally weld the second fillet welds D of all stiffening plates 3 in one go.

[0058] This "type-based, batch-based, and symmetrical" welding strategy ensures that heat is evenly distributed across the entire flange 2, avoiding heat concentration and angular deformation caused by localized continuous welding. Process verification has shown that using this sequence, the flatness of flange 2 can be controlled within 0.5mm.

[0059] (III) Second welding stage (intermittent circumferential weld E) Referring to the indexing and rotation method of the first welding stage, the welding robot is controlled to complete the intermittent circumferential weld E between the flange 2 and the tower 1. This weld is located on the side with stiffener 3 and is divided into multiple segments by stiffener 3. The same half-circle welding + 180-degree rotation mode is used to ensure that the arc start and end positions of each weld segment are at the gaps of stiffener 3.

[0060] (iv) Third welding stage (continuous circumferential weld F) The continuous circumferential weld F is located on the unstiffened side between flange 2 and tower 1. For example... Figure 4 As shown, the end face of tower 1 is a regular polygon (such as a dodecagon). When the polygonal end face is assembled with the circular flange 2, the vertices of the polygon fit tightly (small gap), while the midpoints of the polygon's sides have larger gaps (large gap). In addition, in actual assembly, flange 2 is not flush with the end face of tower 1, but is offset outward by a certain distance (about 2-5mm) using the thickness of the flange itself, forming a very small step.

[0061] The specific steps for this stage are as follows: (1) A laser displacement sensor is installed at the end of the welding robot as a weld seam tracking sensor 9. The control system controls the tower 1 to rotate at a constant speed for one revolution. The sensor emits a laser beam towards the weld seam position and receives the reflected light. The distance from the sensor to the surface of the tower 1 is measured in real time using the triangulation method. Since the end face of the tower 1 is a regular polygon, the measured distance value shows a regular periodic fluctuation - the peak corresponds to the midpoint of the polygon side (large gap), and the trough corresponds to the vertex of the polygon (small gap). The control system records the "angle-distance" data pairs and calculates the distribution curve of the weld seam root gap along the circumferential direction.

[0062] (2) The control system divides the 360-degree circumference into multiple intervals (e.g., one interval every 10 degrees), and calls the corresponding welding parameter group according to the average gap value in each interval: (3) The control system controls the welding robot to weld according to the planned parameters. The robot automatically calls the corresponding parameter group according to the real-time angle and position to realize variable gap adaptive welding.

[0063] VII. Complete Workflow S1: Install the automatic positioning device for stiffeners on the outer side of the flange 2. With the four positioning stiffeners 3 in the open state, hoist the tower 1 and flange 2 onto the active roller frame 4 and the driven roller frame 5. S2: The visual measurement system measures the dimensions of flange 2 or tower 1. The control system controls the automatic positioning device of stiffeners to bring the four positioning stiffeners 3 together radially to fit the surface of tower 1 and spot welds the four positioning stiffeners. S3: Disassemble the automatic positioning device for stiffener plates and spot weld the remaining stiffener plates 3; S4: The first welding stage, all types of welds on all stiffeners 3 are completed in batches and symmetrically. S5: Second welding stage, complete the intermittent circumferential weld E; S6: In the third welding stage, the distribution of the continuous circumferential weld gap F is scanned to perform variable parameter adaptive welding. S7: Lift the welded tower rod 1 away.

[0064] Example 2 (Visual recognition solution to replace laser displacement sensor) This embodiment is basically the same as embodiment 1, except that the gap detection method of the continuous annular weld F is: a visual recognition scheme is used instead of the laser displacement sensor.

[0065] A vision inspection device, including an industrial camera (CCD, 5 megapixels or higher) and a ring LED light source, is installed at the end of the welding robot. The camera is installed at an angle of 30-45 degrees to the weld plane, and can simultaneously capture images of the edge of flange 2, the outer wall of tower 1, and the step surface between the two.

[0066] During inspection, the tower rod 1 is rotated, and one image is acquired at each of the gap positions of the stiffening plate 3 (the middle of each side of the polygon) and the vertex positions. Image processing is used to extract the edges of the flange 2 and the tower rod 1, and the actual gap value is calculated. This is compared with the theoretical gap, and after determining the deviation, a corresponding welding parameter strategy is generated. This embodiment is particularly suitable for the condition where the flange 2 offsets outward to form a step—the image processing algorithm can detect the edge points of the flange 2, the root points of the step, and the outer wall points of the tower rod 1 respectively, calculating the effective gap (the distance from the edge of the flange 2 to the root of the step), thus more accurately reflecting the weld volume that needs to be filled.

[0067] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A welding system for flange stiffeners, characterized in that, Includes a tower (1), a flange (2) at the end of the tower (1), and stiffening plates (3) circumferentially distributed between the flange (2) and the tower (1); a support displacement mechanism, including an active roller frame (4) and a driven roller frame (5), for supporting and driving the tower (1) to rotate about its axis; a first welding robot (7) and a second welding robot (8), respectively fixedly installed on the outer sides of both ends of the tower (1); An automatic positioning device for stiffener plates is located on the outer side of the end of the flange (2). It includes a cross (15), a ring (19), a drive motor (22), a slider (17), and a clamping member (18). The four arms of the cross (15) are respectively provided with guide rails (16). The slider (17) is slidably disposed on the guide rails (16). The clamping member (18) for clamping stiffener plates (3) is disposed on the slider (17). The ring (19) is rotatably disposed on one side of the cross (15). Four spiral guide grooves (20) are opened on the end face of the ring (19). A guide pin (21) is fixed on each slider (17). One end of the guide pin (21) extends into the corresponding spiral guide groove (20). The drive motor (22) is connected to the ring (19) in a transmission. Weld tracking sensor (9) is used to acquire the distribution data of the weld root gap along the circumferential direction; vision measurement system, including industrial camera, after the industrial camera takes an image, extracts the actual size of the outer diameter of the flange (2) or the outer diameter of the tower (1) through image processing, and the control system calculates the target position to which the stiffener (3) needs to be closed and the target angle to which the ring (19) needs to be rotated according to the actual size. The control system is electrically connected to the support displacement mechanism, the first welding robot (7), the second welding robot (8), the stiffener plate automatic positioning device, the weld seam tracking sensor (9), and the vision measurement system, respectively. The automatic positioning device for stiffeners is configured to: based on the measurement results of the vision measurement system, bring the stiffeners (3) together radially to fit the surface of the tower rod (1); The control system is configured to perform the following welding processes: (a) First welding stage: Control the first welding robot (7) and the second welding robot (8) in their respective workspaces to weld the same type of weld on all visible stiffeners (3) on their corresponding end flanges (2); then control the support displacement mechanism to rotate the tower (1) 180 degrees and weld the same type of weld on the remaining stiffeners (3); repeat this process to complete all types of welds on all stiffeners (3) in sequence; (b) Second welding stage: referring to the indexing rotation method in step (a), complete the intermittent circumferential weld between the flange (2) and the tower (1); (c) Third welding stage: Before welding the continuous circumferential weld between the flange (2) and the tower (1), the weld seam is scanned around the weld seam using the weld seam tracking sensor (9) to obtain the distribution data of the root gap along the circumferential direction. The welding parameter group associated with the circumferential position is dynamically generated based on the distribution data. Then, during the welding process, the corresponding welding parameter group is called according to the real-time position to perform variable parameter adaptive welding.

2. The welding system for flange stiffeners according to claim 1, characterized in that, The welds of the stiffening plate (3) include: the first fillet weld A between the stiffening plate (3) and the flange (2), the second fillet weld B between the stiffening plate (3) and the flange (2), the first fillet weld C between the stiffening plate (3) and the tower (1), and the second fillet weld D between the stiffening plate (3) and the tower (1). The welding sequence is as follows: first complete the first fillet weld A between all the stiffening plates (3) and the flange (2), then complete the second fillet weld B between all the stiffening plates (3) and the flange (2), then complete the first fillet weld C between all the stiffening plates (3) and the tower (1), and finally complete the second fillet weld D between all the stiffening plates (3) and the tower (1).

3. The welding system for flange stiffeners according to claim 1, characterized in that, The weld seam tracking sensor (9) is a laser displacement sensor, which is installed at the end of the first welding robot (7) and the second welding robot (8). It measures the distance from the sensor to the surface of the tower (1) or the edge of the flange (2) in real time by using triangulation, thereby calculating the weld seam root gap.

4. The welding system for flange stiffeners according to claim 1, characterized in that, The welding parameter set includes at least one of the following: welding torch oscillation amplitude, welding speed, wire feed speed, welding current, and welding voltage; the control system divides the circumferential direction into multiple intervals according to the size of the root gap value, and matches a corresponding welding parameter set to each interval.

5. The welding system for flange stiffeners according to claim 1, characterized in that, The first welding robot (7) is mounted on the first cantilever (11) of the first column (10), which is fixed to the ground; the second welding robot (8) is mounted on the second cantilever (13) of the second column (12), which has a walking motor (14) at the bottom and can move along the walking track (6); the first cantilever (11) and the second cantilever (13) can move up and down.

6. The welding system for flange stiffeners according to claim 1, characterized in that, The active roller frame (4) drives the tower (1) and the driven roller frame (5) to move on the traveling track (6) via a motor-driven chain.

7. A welding method for flange stiffeners, applied to the welding system according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Install the automatic positioning device for stiffeners on the outer side of the flange (2) end. The four positioning stiffeners (3) are in the open state. Hoist the tower (1) and flange (2) onto the active roller frame (4) and the driven roller frame (5). S2: The visual measurement system measures the dimensions of the flange (2) or tower (1). The control system controls the automatic positioning device of the stiffener plate according to the measurement results to bring the four stiffener plates (3) together radially to fit the surface of the tower (1) and spot weld the four positioning stiffener plates (3). S3: Disassemble the automatic positioning device for stiffeners and spot weld the remaining stiffeners (3). S4: First welding stage: Control the first welding robot (7) and the second welding robot (8) in their workspace to weld the same type of weld on all visible stiffening plates (3) on their respective end flanges (2); control the tower (1) to rotate 180 degrees and weld the same type of weld on the remaining stiffening plates (3); repeat until all types of welds on all stiffening plates (3) are completed; S5: Second welding stage: Refer to the indexing rotation method in step S4 to complete the intermittent circumferential weld E between the flange (2) and the tower (1); S6: Third welding stage: Before welding the continuous circumferential weld F, the weld seam is scanned around the weld seam using the weld seam tracking sensor (9) to obtain the distribution data of the root gap along the circumferential direction; a welding parameter group associated with the circumferential position is generated based on the distribution data; then, during the welding process, the corresponding welding parameter group is called according to the real-time position to perform variable parameter adaptive welding.

8. The welding method for flange stiffeners according to claim 7, characterized in that, In step S4, the welding sequence of the stiffening plate (3) weld is as follows: first weld the first fillet weld A of all stiffening plates (3) and flange (2), then weld the second fillet weld B of all stiffening plates (3) and flange (2), then weld the first fillet weld C of all stiffening plates (3) and tower (1), and finally weld the second fillet weld D of all stiffening plates (3) and tower (1).

9. The welding method for flange stiffeners according to claim 7, characterized in that, In step S6, the distribution data of the root gap is obtained by a laser displacement sensor. The sensor emits a laser beam toward the weld position and receives the reflected light. The distance from the sensor to the surface of the tower (1) is measured in real time by the triangulation method. Since the end face of the tower (1) is a regular polygon, the measured distance value shows periodic fluctuations. The root gap is obtained by calculating the difference between the measured distance and the theoretical distance.

10. The welding method for the flange stiffener plate according to claim 7, characterized in that, In step S2, the four stiffening plates (3) are first spot welded to the flange (2) at the positions of 0°, 90°, 180° and 270°, and then the remaining stiffening plates (3) are spot welded.

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