Automatic circumferential welding device for pipe, and circumferential welding method

Abstract

An automatic circumferential welding device for a pipe, and a circumferential welding method. The automatic circumferential welding device for a pipe comprises a welding track (1) and a motorized assembly for providing traveling power for the welding track (1), wherein two free ends of the welding track (1) extend along an outer wall of a pipe and close together to wrap around the outer wall of the pipe in an annular structure, the motorized assembly comprises a power roller (36) for providing power for the welding track to roll along the outer wall of the pipe, and a plurality of rollers (2) are rotationally embedded in the side wall of the welding track that faces the pipe.

Description

Automatic pipe ring welding device and ring welding method Technical Field

[0001] This invention relates to the field of pipeline welding technology, specifically to an automatic pipe ring welding device and a ring welding method. Background Technology

[0002] Large-diameter pipelines are widely used in various industries. However, due to the large diameter of these pipelines, existing construction equipment struggles to handle their hoisting, transportation, and assembly when they are formed as a single unit. For example, in current technology, the assembly site for large pipelines within the cavities of high-speed railway station platforms is located in the basement. Therefore, these large-diameter pipelines are typically pre-fixed using an assembly method, and connected by welding the ends together to meet actual usage requirements as sewage pipes, rainwater pipes, and water supply pipes.

[0003] For welding large-diameter pipes, the welding method involves aligning the ends of two adjacent pipes to be welded without gaps. An automatic welding carriage, equipped with a welding power source, welding torch, and control system, moves along a preset track to perform the welding operation on the large-diameter pipes. For example, the Chinese utility model patent CN 207806944 U, entitled "Automatic Welding Cart Drive Track," uses a combination of protrusions and grooves to create a stable and finely adjustable gap between the first and second track bodies through a cross-connection. Because the welding position of the pipe is uncertain—for example, the weld may be on a horizontal section or a curved section—existing automatic welding carriages perform circular guided welding along horizontal sections without significant error. However, for curved sections, the curvature is inconsistent. The guide track, located in the curved section, is relatively wide and non-adjustable, making it impossible to bend. This leads to inaccurate circular positioning of the automatic welding carriage, causing deviations from the weld seam and incomplete welding, resulting in compromised weld quality. Summary of the Invention

[0004] The purpose of this invention is to provide an automatic pipe ring welding device and a ring welding method to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An automatic pipe ring welding device, comprising:

[0007] The welding rail is installed on the side of the pipe near the weld during operation; the two free ends of the welding rail extend along the outer wall of the pipe and are wrapped around the outer wall of the pipe.

[0008] Mobility components, mounted on welding rails, are used to provide propulsion.

[0009] Mounting bracket, mounted on the motorized assembly, is used to mount and fix the welding unit;

[0010] The mobility components include:

[0011] The mounting box contains an internal motor;

[0012] A control box is fixed to the outer wall of the mounting box. The control box contains a control module for controlling the motor and welding unit. During welding, the control box controls the working status of the motor and welding unit.

[0013] A power roller is used to provide the power for movement along the outer wall of a pipe.

[0014] The welding track is a strip structure. One of the free ends of the welding track narrows to form an interpenetrating end. The other free end of the welding track has a notch for accommodating the interpenetrating end. Two connecting blocks located on both sides of the notch are fixedly connected to the other free end of the welding track. An I-shaped crossbar is inserted between the two connecting blocks. A limiting piece extending into the notch is fixed to the radial side wall of the crossbar. A slot for engaging the end of the limiting piece is opened on the side wall of the interpenetrating end facing the limiting piece.

[0015] According to one aspect of this application,

[0016] The welding track has a through hole; multiple rollers are rotatably embedded in the side wall of the welding track facing the pipe, and the multiple rollers and the power roller form a power support frame for the welding equipment to move automatically in a ring along the outer wall of the pipe; during operation, the motor component drives the welding track to move along the pipe as a whole.

[0017] Alternatively, slide rails are installed on both sides of the outer wall of the welding track, and arc-shaped notches are opened on the opposite side walls of the two slide rails. Slider blocks are installed on both sides of the mounting box to slide and engage with the arc-shaped notches of the slide rails; the sliders of the mounting box slide and engage with the arc-shaped notches of the two slide rails; during operation, the motor component drives the control box and the welding unit to move along the welding track.

[0018] According to one aspect of this application, an automatic pipe annular welding device is also provided, comprising a welding track that can be arranged along the pipe at a position located on the side of the weld seam, a motor assembly mounted on the welding track to provide travel power for the welding track, and a mounting base mounted on the motor assembly for mounting welding equipment. The motor assembly includes a mounting box with an embedded electric motor and a control box fixed to the outer wall of the mounting box. The control box contains a control module for controlling the electric motor. The two free ends of the welding track extend along the outer wall of the pipe and converge to wrap around the outer wall of the pipe in an annular structure. The motor assembly includes a power roller that provides power for the welding track to roll along the outer wall of the pipe.

[0019] In a further embodiment, a through hole is provided on the welding track, and the radial outer wall of the power roller extends out of the through hole and rolls and presses against the outer wall of the pipe;

[0020] In a further embodiment, multiple rollers are rotatably embedded on the side wall of the welding track facing the pipe. The rollers and the power roller protrude from the outer wall of the welding track at the same height. The multiple rollers and the power roller form a power support frame for the welding equipment to automatically move in a ring along the outer wall of the pipe.

[0021] In a further embodiment, the mounting box is fixed on the side wall of the welding track located at the through hole, the output end of the motor is connected to a gear plate, a matching hole is opened on the side wall of the mounting box opposite to the through hole, the power roller is rotatably arranged in the matching hole, and a tooth groove that meshes with the gear plate is opened at one axial end of the power roller.

[0022] In a further embodiment, the mounting base and the control box are adjustablely connected. A protrusion is fixed on the back side wall of the mounting base, and a threaded adjustment rod is rotatably provided on the side wall of the control box. The protrusion has a threaded hole that is threadedly connected to the threaded adjustment rod. A guide groove is provided on the back side wall of the mounting base, and a guide block that is slidably engaged with the guide groove is fixed on the side wall of the control box.

[0023] In a further embodiment, there are two crossbars, and an insertion space is provided between the two crossbars for the insertion end to pass through. There are two limiting pieces, and the ends of the two limiting pieces extend toward each other. The other side wall of the insertion end is also provided with a groove for locking with the end of the other limiting piece.

[0024] In a further embodiment, one of the connecting blocks has a hollow cavity, and the two crossbars extend rotatably into the hollow cavity at the same end. The upper crossbar is fixed with an elastic lever in a C-shape structure located in the hollow cavity, and the lower crossbar is fixed with an extension rod located in the hollow cavity. A vertical rod is fixed to the upper side of the end of the extension rod near the crossbar, and the end of the vertical rod is hinged to the end of the lever.

[0025] The bottom wall of the hollow cavity is fixed with a limiting seat, and the limiting seat extends upward with a limiting part. The two side walls of the limiting part are arc-shaped structures, and elastic steel rings are provided on the arc-shaped structures. Pressure blocks are fixed on both sides of the end of the extension rod and are respectively fixedly connected to the outer walls of the two elastic steel rings.

[0026] In a further embodiment, the welding track contains an elastic steel sheet extending along the direction of the welding track wound around the outer wall of the pipe.

[0027] In a further embodiment, the multiple rollers are divided into multiple groups, with two rollers in each group, and the two rollers in each group are symmetrically distributed around the elastic steel sheet.

[0028] In a further embodiment, a reinforcing plate embedded in the welding track is connected between each set of two rollers. The reinforcing plate has a curved structure, and the side wall of the reinforcing plate has a snap-fit ​​interface for engaging with an elastic steel sheet.

[0029] According to another aspect of this application, a method for welding annular pipes using an automatic pipe annular welding device is also provided. This method employs any of the aforementioned automatic pipe annular welding devices, and the welding device is equipped with an image acquisition unit. The method includes the following steps:

[0030] Step S1: Read the pre-configured welding parameter configuration database in the control module, as well as the real-time welding image and pipeline image acquired by the image acquisition unit; and perform noise reduction, enhancement and normalization processing on the acquired images; the welding parameter configuration database is configured with the mapping relationship between pipeline curvature, welding trajectory and optimal welding parameters;

[0031] Step S2: Use an edge detection method based on local adaptive threshold to identify and fit the pipe curvature, and use an image segmentation method to obtain the welding trajectory on the pipe surface to obtain the current pipe curvature and welding trajectory data;

[0032] Step S3: Based on the current pipe curvature and welding trajectory data, search for the current optimal welding parameters in the welding parameter configuration database;

[0033] Step S4: Compare the current optimal welding parameters with the current real-time welding parameters, and adjust the motion trajectory parameters and welding parameters of the welding unit.

[0034] According to one aspect of this application, the process of fitting the pipe curvature and the welding trajectory further comprises:

[0035] Step S21: Divide the preprocessed image into overlapping local windows of size n×n, with the center pixel coordinates of each window being (i,j); n is a natural number greater than 0, and i and j are coordinate values;

[0036] Step S22: For each local window, calculate the mean μ(i,j) and standard deviation σ(i,j) of the pixel gray values ​​within the window; based on the mean and standard deviation, adaptively calculate the local threshold T(i,j) = μ(i,j) + k × σ(i,j), where k is a predefined constant; for the center pixel (i,j) of the window, if its gray value is greater than the local threshold T(i,j), then mark it as an edge point; otherwise, mark it as a non-edge point.

[0037] Step S23: Slide the window and repeat step S22 until all pixels of the entire image have been processed; further refine and connect the marked edge points to obtain the final pipe edge;

[0038] Step S24: Represent the detected pipe edge point set as (x i ,y i ) i＝1 N , where N is the number of edge points; for each edge point (x i ,y i Define a local neighborhood N i , including its K nearest neighbors; in the local neighborhood N i Within the boundary points, a weighted polynomial regression is performed to fit a p-th degree polynomial curve f. i (x) = a0 + a1x + ... + a p x p ;

[0039] Step S25, in weighted regression, each neighborhood point (x j ,y j The weight w j Determined by the Gaussian kernel function: w j =exp(-||x j -x i || 2 / (2h 2 (), where h is the bandwidth parameter; by minimizing the weighted mean square error, the polynomial coefficients {a0, a1, ..., a p}, thus obtaining the local fitting curve f i (x);

[0040] Step S26: Repeat steps S23 and S24 for all edge points to obtain a set of local fitting curves f i (x) i＝1 N The local fitted curves are combined into a global curve F(x) by weighted averaging. The global curve F(x) is then smoothed and its curvature is calculated to obtain the final curvature estimate of the pipeline.

[0041] In some embodiments, other installation processes are as follows: First, align the openings of the two pipes to be welded. Then, extend the two free ends of the welding track along the outer wall of the pipe and join them in a ring structure around the outer wall of one of the pipes so that the welding torch of the welding equipment can be aligned with the weld position. Subsequently, multiple rollers and a power roller are used to form a power support frame for the welding equipment to move automatically in a ring along the outer wall of the pipe. The power roller drives multiple rollers to provide power for the welding track to move in a ring around the outer wall of the large-diameter pipe. Then, the welding equipment installed on the mounting base moves and welds in a circular trajectory. Once the welding equipment has traveled one circle, the weld can be fully welded.

[0042] Compared with the prior art, the beneficial effects of the present invention are:

[0043] The welding track used in this invention has a small lateral width. Its function is to position the welding equipment relative to the outer wall of the pipe, so that the movement trajectory of the welding equipment does not deviate from the circular structure with the pipe axis as the center of rotation. Therefore, it is only necessary to wrap the welding track in a ring structure around the outer wall of the horizontal section or the outer wall of the curved section of the pipe. The power roller drives multiple rollers to provide power for the welding track to move in a ring around the outer wall of the large-diameter pipe. This allows the welding equipment installed on the mounting base to move and weld in a circular trajectory, solving the problem that the existing ring guide rail is too wide and cannot be adjusted, making it unsuitable for ring guidance in the curved section of the pipe. Attached Figure Description

[0044] Figure 1 is a schematic diagram of the main structure of the present invention.

[0045] Figure 2 is a schematic diagram of the welding track structure of the present invention.

[0046] Figure 3 is a schematic diagram of the limiting piece structure of the present invention.

[0047] Figure 4 is a partial cross-sectional view of the assembly of the limiting piece and the welding track of the present invention.

[0048] Figure 5 is a partial cross-sectional view of the welding track of the present invention.

[0049] Figure 6 is a schematic diagram of the assembly structure of the same group of two pulleys of the present invention.

[0050] Figure 7 is an exploded view of the mechanical component structure of the present invention.

[0051] Figure 8 is a schematic diagram of the disassembled structure of the motor component of the present invention.

[0052] Figure 9 is a schematic diagram of the welding equipment guide device of the present invention being prepared for installation on the bend of the pipe.

[0053] Figure 10 is a schematic diagram of the welding equipment of the present invention installed on the bend of a pipe.

[0054] Figure 11 is a schematic diagram of another improved structure of the welding equipment of the present invention installed in the bend of a pipe.

[0055] In the diagram: 1. Welded track; 11. Connecting block; 12. Crossbar; 13. Limiting plate; 14. Elastic lever; 15. Extension rod; 16. Upright pole; 17. Pressure block; 18. Limiting seat; 19. Elastic steel ring; 2. Roller; 21. Reinforcing plate; 3. Mounting box; 31. Control box; 32. Threaded adjusting rod; 33. Protrusion; 34. Motor; 35. Gear disc; 36. Power roller; 4. Mounting seat; 5. Elastic steel sheet. Detailed Implementation

[0056] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0057] This embodiment provides an automatic annular welding device for pipelines, including a welding track 1 that can be set along the pipeline at the weld seam side, a motorized component mounted on the welding track 1 to provide travel power for the welding track 1, and a mounting base 4 mounted on the motorized component for mounting welding equipment. The welding equipment adopts manual electric arc welding or carbon dioxide gas shielded welding, as shown in Figures 1, 9, 10, and 11. The mounting base 4 has L-shaped mounting portions extending from both sides, with multiple mounting holes on the L-shaped mounting portions for alignment with pre-drilled holes in the welding equipment. Assembly is then achieved by bolts passing through the mounting holes and pre-drilled holes. Before welding, the welding track 1 is set in an annular structure along the pipeline at the weld seam side, allowing the motorized component and the welding equipment mounted on the mounting base 4 to be positioned along the outer wall of the pipeline. During welding, the motorized component provides annular transmission power to the welding track 1, enabling the welding equipment to run in an annular trajectory, performing welding operations on the weld seam during the annular trajectory movement.

[0058] Specifically, as shown in Figures 7 and 8, the motor assembly includes a mounting box 3 with an embedded motor 34 and a control box 31 fixed to the outer wall of the mounting box 3. The control box 31 contains a control module for controlling the motor 34. The control module controls the parameters of the motor 34. The parameter settings of the motor 34 refer to the Chinese invention disclosed in publication number CN107486654B, entitled "Automatic Welding Cart, Fault Identification Method and Device for Automatic Welding Cart": The speed regulation process of the motor is a closed-loop regulation process. The speed regulation principle of the motor is to provide a preset given speed to the motor to control the motor rotation, and then control the motor speed by detecting the actual speed of the motor and combining it with the preset given speed to perform proportional and integral adjustment output. The given speed Vset(t) is the welding speed set at time t during the welding process, and the speed feedback Vfb(t) at time t during the welding process is the actual speed of the motor.

[0059] The motorized assembly includes a power roller 36 that provides power for the welding track 1 to roll along the outer wall of the pipe. An electric motor 34 provides power to the power roller 36. Specifically, as shown in Figures 2 and 8, a mounting box 3 is fixed to the side wall of the welding track 1 located at the through hole. A geared disc 35 is connected to the output end of the electric motor 34. A matching hole is provided on the side wall of the mounting box 3 opposite to the through hole. The power roller 36 is rotatably positioned within the matching hole. One axial end of the power roller 36 has a toothed groove that meshes with the geared disc 35. The electric motor 34 drives the geared disc 35 to rotate within the mounting box 3. The power roller 36 matches the geared disc 35 through the toothed groove and rotates synchronously with the rotating geared disc 35, providing power for the power roller 36 to roll along the outer wall of the pipe.

[0060] The two free ends of welding track 1 extend along the outer wall of the pipe and converge to form a ring structure, wrapping around the outer wall of the pipe. Welding track 1 has through holes. The radial outer wall of power roller 36 extends out of the through holes and rolls against the outer wall of the pipe. Multiple rollers 2 are embedded in the side wall of welding track 1 facing the pipe. The radial outer walls of the rollers 2 and power roller 36 protrude from the surface of welding track 1 at the same height. After welding track 1 is bound to the outer wall of the pipe, the multiple rollers 2 and power roller 36 form a power support frame for the welding equipment to automatically move in a ring along the outer wall of the pipe. The specific automatic ring guiding process is as follows: As shown in Figure 9, welding track 1 is bound to the outer wall of the curved section of the pipe, and multiple ring-shaped protrusions are spot-welded to the outer walls of the two pipes to be welded. These protrusions serve as side limiters when welding track 1 moves in a ring, preventing lateral slippage and ensuring the weld points do not deviate from their preset positions. The power roller 36 drives multiple rollers 2 to provide power for the welding track 1 to move in a circular motion around the outer wall of the large-diameter pipe. This allows the welding equipment mounted on the mounting base 4 to move and weld along a circular trajectory. One complete circle of the welding equipment completes the weld. This solves the problem that existing circular guide rails are too wide and non-adjustable, making them unsuitable for guiding pipes in curved sections.

[0061] The welding track 1, with its narrow lateral width, serves to position the welding equipment relative to the outer wall of the pipe, ensuring its movement trajectory remains within a circular structure centered on the pipe's axis. Therefore, regardless of whether the weld is located on the outer wall of a horizontal or curved section of the pipe, the two free ends of the welding track 1 extend axially along the pipe, eventually merging and securing themselves together, forming a ring-like structure around the pipe's outer wall. The welding track 1 can be made of woven cotton fabric, a 0.7-1cm thick, 4-8cm wide flat canvas strip, or other materials with slight bending deformation characteristics. This specification of welding track 1 meets the support requirements for wrapping around the outside of the pipe and is suitable for wrapping and binding horizontal pipe sections. Furthermore, the narrow lateral width of the welding track 1 prevents excessive lateral bending when wrapping around curved pipe sections, thus ensuring adequate wrapping and binding for curved sections.

[0062] The welding rail 1 we use has the following characteristics: it has a certain tensile strength to prevent excessive tensile deformation when the welding equipment is installed on the mounting base 4 and subjected to the weight of the welding equipment. This would prevent the welding rail 1 from stretching too much when the welding equipment moves under the pipe, causing the welding torch tip to be far from the weld seam, resulting in incomplete weld seam sealing and gaps. Furthermore, the welding rail 1 is not a rigid material and has a slight bending characteristic. This means that when the welding rail 1 is attached to a curved section of the pipe, it ensures that it fully conforms to the outer wall of the pipe, preventing any part of the welding rail 1 from being suspended. This would cause significant shaking during the circular rolling of the welding equipment, leading to frequent changes in the distance between the welding torch tip and the weld seam. On the one hand, the welding torch may be too close to the weld seam, causing the weld to be burned through; on the other hand, the welding torch may be too far from the weld seam, resulting in incomplete weld seam sealing.

[0063] Of course, the welding equipment is installed on the mounting base 4, and the welding rail 1 is wrapped around the outer wall of the pipe, so that the welding equipment is located on one side of the weld seam, and the tip of the welding torch is aligned with the weld seam. Generally, the workers install the welding rail 1 by visually observing that the welding torch is roughly aligned with the weld seam, and then fix the welding rail 1 in place. Slight deviations are inevitable. In order to avoid misalignment between the tip of the welding torch and the weld seam, the mounting base 4 and the control box 31 are adjustablely connected. Specifically, a protrusion 33 is fixed on the side wall of the back of the mounting base 4, and the side wall of the control box 31 rotates. The device includes a threaded adjusting rod 32 and a protrusion 33 with a threaded hole for threaded connection with the adjusting rod 32. A guide groove is provided on the back side wall of the mounting base 4. A guide block, which slides and engages with the guide groove, is fixed to the side wall of the control box 31, as shown in Figure 7. Manually rotating the threaded adjusting rod 32 moves the protrusion 33 along the axial direction of the adjusting rod 32, thus adjusting the horizontal position of the mounting base 4 relative to the control box 31. The guide block slides horizontally with the guide groove, ensuring that the mounting base 4 does not wobble during horizontal adjustment. Adjusting the mounting base 4 laterally allows for slight horizontal adjustment of the welding torch.

[0064] The welding track 1 is a strip structure. One free end of the welding track 1 narrows to form an interpenetrating end, and the other free end of the welding track 1 has a notch for accommodating the interpenetrating end. Two connecting blocks 11 located on both sides of the notch are fixedly connected to the other free end of the welding track 1. An I-shaped crossbar 12 is inserted between the two connecting blocks 11. A limiting piece 13 extending inward toward the notch is fixed to the radial side wall of the crossbar 12. A slot for engaging the end of the limiting piece 13 is opened on the side wall of the interpenetrating end facing the limiting piece 13. The two free ends of the welding track 1 are fastened as follows: according to the outer diameter of the pipe, the interpenetrating end and the other end of the welding track 1 are wound in a ring structure along the outer wall of the pipe, so that the interpenetrating end extends along the notch until it can no longer be pulled out along the notch. At this time, the end of the limiting piece 13 is engaged in the corresponding slot of the interpenetrating end to prevent the welding track 1 from becoming loose.

[0065] Furthermore, two crossbars 12 are provided, with an insertion space between them for the insertion end to pass through. Two limiting pieces 13 are provided, with their ends extending towards each other. A groove for locking the end of the other limiting piece 13 is also provided on the other side wall of the insertion end. As shown in Figures 3 and 4, the insertion end is passed through the insertion space and pulled along the notch until it can no longer be pulled along the notch. The ends of the two limiting pieces 13 are then locked into the corresponding grooves of the insertion end to prevent the welding track 1 from becoming loose.

[0066] Of course, after the two free ends of the welding track 1 are fastened, it is convenient for the welding equipment to make a circular trajectory. After the welding is finished, it needs to be removed. In order to quickly remove the welding track 1, a hollow cavity is provided in one of the connecting blocks 11. The two crossbars 12 extend into the hollow cavity from the same end. The upper crossbar 12 is fixed with an elastic lever 14 with a C-shaped structure located in the hollow cavity. The lower crossbar 12 is fixed with an extension rod 15 located in the hollow cavity. The upper side of the extension rod 15 near the crossbar 12 is fixed with a vertical rod 16. The end of the vertical rod 16 is hinged to the end of the lever. The bottom wall of the hollow cavity is fixed with a limiting seat 18. The limiting seat 18 extends upward with a limiting part. The side walls of the limiting part are arc-shaped structures, and elastic steel rings 19 are provided on the arc-shaped structures. The two sides of the extension rod 15 are fixed with pressure blocks 17 that are fixedly connected to the outer walls of the two elastic steel rings 19 respectively. A relatively vertical handle is provided on the upper horizontal bar 12. The operator can hold the handle and push it laterally away from the notch, giving the upper horizontal bar 12 a rotational force that can push the upper limiting piece 13 upward, allowing the end of the upper limiting piece 13 to disengage from the corresponding slot. Simultaneously, the rotation of the upper horizontal bar 12 causes the elastic lever 14 to rotate in a specific direction. Since the elastic lever 14 is hinged to the upright rod 16, the end of the elastic lever 14 pushes the upright rod 16 to rotate towards the side closer to the inside of the notch, thus giving the lower horizontal bar 12 a rotational force opposite to that of the upper horizontal bar 12, thereby causing the lower limiting piece 13 to disengage from the corresponding slot. At this point, both limiting pieces 13 are completely disengaged from their corresponding slots, allowing the piercing end to be pulled out of the insertion space, achieving rapid disassembly of the welding rail 1.

[0067] Furthermore, during the process of the limiting piece 13 being inserted into the corresponding slot, the elastic potential energy of the elastic steel rings 19 on both sides of the limiting seat 18 is used to prevent the pressure block 17 on either side of the extension rod 15 from having a tendency to rotate around the extension rod 15. This can prevent the upper and lower crossbars 12 from rotating arbitrarily, causing the limiting piece 13 to disengage from the slot and affecting the binding stability of the welding track 1.

[0068] As shown in Figure 5, an elastic steel sheet 5 is embedded inside the welding track 1, extending along the direction of the welding track 1 winding around the outer wall of the pipe. By setting the elastic steel sheet 5, it has both bending deformation characteristics at one end and supporting strength at the other end. In this way, when the welding track 1 is wound around the outer wall of the pipe, the elastic steel sheet 5 bends around the outer wall of the pipe in sync with the welding track 1 and is bound to the outer wall of the pipe. At the same time, the supporting strength of the elastic steel sheet 5 is used to prevent the welding track 1 from being stretched excessively by the welding equipment, resulting in large tensile deformation, which would cause the distance between the welding torch and the weld to become uncontrollable and affect the quality of the weld.

[0069] Furthermore, the multiple rollers 2 are divided into multiple groups, with two rollers 2 in each group, and the two rollers 2 in each group are symmetrically distributed around the elastic steel sheet 5. The multiple groups of rollers 2 are positioned as shown in Figure 5. This arrangement does not affect the setting of the notch, and thus does not affect the smooth entry of the insertion end into the notch to tension the welding track 1. As shown in Figure 6, a reinforcing plate 21 embedded in the welding track 1 is connected between the two rollers 2 in each group. The reinforcing plate 21 has a curved structure, and its side wall has a snap-fit ​​interface that engages with the elastic steel sheet 5. The purpose of the rollers 2 is to cooperate with the power roller 36 to drive the welding track 1 to make a circular motion on the outer wall of the pipe. At the same time, with the rollers 2 as rolling support points, the reinforcing plate 21 connected between the two rollers 2 in each group can enhance the lateral support strength of the welding track 1, and prevent the welding track 1 from flipping over on the outer wall of the pipe, which would cause the welding equipment to shake and affect the accuracy of the distance between the welding torch and the weld.

[0070] As shown in Figure 10, the rollers 2 can be removed from the inner wall of the welding track 1, and slide rails can be installed on both sides of the outer wall of the welding track 1. The two slide rails have arc-shaped notches on their opposite side walls. Slider blocks that slide and engage with the arc-shaped notches of the slide rails are installed on both sides of the mounting box 3. The welding track 1 is bound to one of the curved sections of the pipe to be welded near the welding position. Then, the sliders of the mounting box 3 slide and engage with the arc-shaped notches of the two slide rails. The motor 34 drives the gear plate 35 to rotate inside the mounting box 3. The power roller 36 matches the gear plate 35 through its tooth groove and rotates synchronously with the rotating gear plate 35, providing power for the power roller 36 to roll along the outer wall of the pipe. The power roller 36 rolls along the outer wall of the welding track 1, which drives the welding equipment installed on the mounting plate 4 to make a circular motion along the outer wall of the welding track 1, and performs welding operations on the weld seam while moving.

[0071] Based on the outer diameter of the pipe, the insertion end and the other end of the welding rail 1 are wound in a ring structure along the outer wall of the pipe, so that the insertion end extends along the notch until it can no longer be pulled out along the notch. At this point, the end of the limiting piece 13 is engaged in the corresponding slot of the insertion end, thus binding the welding rail 1 to the outer wall of the pipe. It should be further noted that the length of the insertion end outside the notch, i.e., the distance between the two ends of the slide rail, must not exceed the spot welding range of the welding head of the welding equipment to ensure that the welding equipment performs a ring welding operation on the outer wall of the pipe after its ring movement.

[0072] In some embodiments, according to another aspect of this application, a method for welding annular pipes using an automatic pipe annular welding device is also provided, which is implemented using any of the above-described automatic pipe annular welding devices, wherein the welding device is equipped with an image acquisition unit, and includes the following steps:

[0073] Step S1: Read the pre-configured welding parameter configuration database in the control module, as well as the real-time welding image and pipeline image acquired by the image acquisition unit; and perform noise reduction, enhancement and normalization processing on the acquired images; the welding parameter configuration database is configured with the mapping relationship between pipeline curvature, welding trajectory and optimal welding parameters;

[0074] Step S2: Use an edge detection method based on local adaptive threshold to identify and fit the pipe curvature, and use an image segmentation method to obtain the welding trajectory on the pipe surface to obtain the current pipe curvature and welding trajectory data;

[0075] Step S3: Based on the current pipe curvature and welding trajectory data, search for the current optimal welding parameters in the welding parameter configuration database;

[0076] Step S4: Compare the current optimal welding parameters with the current real-time welding parameters, and adjust the motion trajectory parameters and welding parameters of the welding unit.

[0077] According to one aspect of this application, the process of fitting the pipe curvature further comprises:

[0078] Step S21: Divide the preprocessed image into overlapping local windows of size n×n, with the center pixel coordinates of each window being (i,j); n is a natural number greater than 0, and i and j are coordinate values;

[0079] Step S22: For each local window, calculate the mean μ(i,j) and standard deviation σ(i,j) of the pixel gray values ​​within the window; based on the mean and standard deviation, adaptively calculate the local threshold T(i,j) = μ(i,j) + k × σ(i,j), where k is a predefined constant; for the center pixel (i,j) of the window, if its gray value is greater than the local threshold T(i,j), then mark it as an edge point; otherwise, mark it as a non-edge point.

[0080] Step S23: Slide the window and repeat step S22 until all pixels of the entire image have been processed; further refine and connect the marked edge points to obtain the final pipe edge;

[0081] Step S24: Represent the detected pipe edge point set as (x i ,y i ) i＝1 N , where N is the number of edge points; for each edge point (x i ,y i Define a local neighborhood N i , including its K nearest neighbors; in the local neighborhood N i Within the boundary points, a weighted polynomial regression is performed to fit a p-th degree polynomial curve f.i (x) = a0 + a1x + ... + a p x p ;

[0082] Step S25, in weighted regression, each neighborhood point (x j ,y j The weight w j Determined by the Gaussian kernel function: w j =exp(-||x j -x i || 2 / (2h 2 (), where h is the bandwidth parameter; by minimizing the weighted mean square error, the polynomial coefficients {a0, a1, ..., a p}, thus obtaining the local fitting curve f i (x);

[0083] Step S26: Repeat steps S23 and S24 for all edge points to obtain a set of local fitting curves f i (x) i＝1 N The local fitted curves are combined into a global curve F(x) by weighted averaging. The global curve F(x) is then smoothed and its curvature is calculated to obtain the final curvature estimate of the pipeline.

[0084] Step S4 also includes real-time monitoring of the welding process using infrared thermal imaging to detect any abnormalities or defects.

[0085] In step S2, the process of obtaining the welding trajectory on the pipe surface through image segmentation is specifically implemented using an image segmentation model. The construction and use of the image segmentation model are as follows:

[0086] Step S27: Represent the original input image as x, and its corresponding real welding trajectory segmentation mask as y;

[0087] Construct a generator network G and a discriminator network D, which are optimized through adversarial training;

[0088] The generator G receives the input image x and generates a pseudo segmentation mask G(x);

[0089] Discriminator D receives the real image-mask pair (x,y) and the generated image-mask pair (x,G(x)) and attempts to distinguish them;

[0090] The generator G and discriminator D are trained by minimizing the following adversarial loss function:

[0091] Generator loss: LG = Ex[log(1-D(x,G(x)))] + λLseg(G(x),y);

[0092] Discriminator loss: LD = -E{(x,y)}[logD(x,y)] - Ex[log(1-D(x,G(x)))];

[0093] Where Lseg is the segmentation loss, such as cross-entropy loss, and λ is a hyperparameter that balances the two loss terms.

[0094] During training, the generator G attempts to generate realistic segmentation masks to deceive the discriminator, while the discriminator D tries to distinguish between real and generated masks.

[0095] Through multiple rounds of adversarial training, the generator G gradually learns to generate results similar to the real segmentation mask.

[0096] During the inference phase, for a given input image x, the trained generator G(x) is used to directly generate the corresponding welding trajectory segmentation mask.

[0097] In step S1, the process of constructing the mapping relationship between pipe curvature, welding trajectory, and optimal welding parameters is specifically achieved through high-dimensional functional regression, and further includes:

[0098] The pipe curvature, welding trajectory, and optimal welding parameters are represented as a high-dimensional feature vector (x). i ,y i ) i＝1 N , where x i Representing curvature and trajectory characteristics, y i This indicates the corresponding welding parameters.

[0099] Define a high-dimensional functional space H, where each element is a mapping function f from the feature space to the welding parameter space.

[0100] In the functional space H, assume that the optimal mapping function f* satisfies the following optimization problem:

[0101] f*=argmin f∈H ∑ i＝1 N L(f(x i ),y i )+α||f|| H 2 ;

[0102] Where L is the loss function (e.g., mean squared error), ||f|| H α is the norm of the function f in the functional space H, and α is the regularization parameter.

[0103] By introducing a kernel function k(x,x'), the optimization problem is transformed into an equivalent dual problem, and the expression for the optimal mapping function f* is obtained: f*(x)=∑ i＝1 N β i k(x,x i );

[0104] Where, β i It is the solution to the dual problem, and k(x,x') is the chosen Gaussian kernel function.

[0105] Using training data (x) i ,y i ) i＝1 N Estimate the solution β of the dual problem i The optimal mapping function f* is obtained.

[0106] For the new curvature and trajectory features x new The learned mapping function f* is used to predict the corresponding optimal welding parameters: y new =f*(x new ).

[0107] In a further embodiment, the process of adjusting the motion trajectory parameters and welding parameters of the welding unit can also be as follows:

[0108] Step S41: Implement the motion adjustment strategy based on adaptive control, specifically including:

[0109] Define the objective function J(t) for the pipe curvature change and welding quality requirements, representing the welding performance index at time t.

[0110] Establish a dynamic model between the motion parameters of the welding device (such as velocity and acceleration), the pipe curvature, the welding parameters, and the objective function: dx(t) / dt=f(x(t),u(t),t);

[0111] Where x(t) is the state variable of the welding device (such as position and speed), and u(t) is the control input (such as the adjustment amount of speed and acceleration).

[0112] Design an adaptive controller to dynamically adjust the control input u(t) based on real-time measurements of pipe curvature and weld quality feedback, minimizing the objective function J(t). The adaptive control method will be described below.

[0113] During real-time control, the adaptive controller calculates the optimal control input u*(t) based on the current pipe curvature and welding quality feedback, and applies it to the motion execution system of the welding device.

[0114] The actual motion state x(t) of the welding device and the welding quality index J(t) are continuously monitored and fed back to the adaptive controller to form a closed-loop control.

[0115] By continuously and adaptively adjusting the control input u(t), the motion trajectory and speed of the welding device are made to adapt to the changes in the curvature of the pipeline and meet the welding quality requirements.

[0116] In a further embodiment, the adaptive control method is specifically as follows:

[0117] Establish a nonlinear dynamic model relating the motion of the welding device to the pipe curvature and welding parameters: dx(t) / dt=f(x(t),u(t),w(t),t);

[0118] Where x(t) is the state variable of the welding device (e.g., position, velocity), u(t) is the control input, and w(t) is the external disturbance term representing the change in pipe curvature and the uncertainty of the welding process. The Lyapunov exponent from chaos theory is introduced to measure the system's sensitivity to changes in initial conditions and parameters. The Lyapunov exponent is defined as: λ = lim {t→∞} (1 / t)log(||δx(t)|| / ||δx(0)||); where δx(t) represents the small perturbation of the state variable, and ||·|| represents the norm of the vector.

[0119] Building an adaptive robust controller consists of two main parts:

[0120] Adaptive estimator: Based on the real-time measured state variable x(t) and control input u(t), the Lyapunov exponent λ(t) of the system is estimated online.

[0121] Suppose that the Lyapunov exponent can be represented by a set of basis functions φ i We approximate it using a linear combination of (x): λ(x)≈∑ i＝1 N θ i φ i (x);

[0122] Where, θ i is the parameter to be estimated, and N is the number of basis functions.

[0123] Define the estimation error as: e(t) = λ(t) - ∑ i＝1 N θ i (t)φ i (x(t));

[0124] Update parameter θ using gradient descent i dθ i (t) / dt=-ηe(t)φ i(x(t)); where η is the learning rate.

[0125] Robust controller: Adjust the control law based on the estimated Lyapunov exponent λ(t) to suppress chaotic behavior and improve the robustness of the system.

[0126] Based on the estimated Lyapunov exponent λ(t), a robust control law u(t) is constructed: u(t) = -K(t)x(t);

[0127] Here, K(t) is the adaptive gain matrix, used to suppress chaotic behavior.

[0128] Using Lyapunov stability theory, the update law for the adaptive gain matrix K(t) is designed as follows: dK(t) / dt=αexp(βλ(t))I-γK(t);

[0129] Where α, β, and γ are positive constants, and I is the identity matrix.

[0130] During real-time control, the adaptive estimator continuously updates the estimated value λ(t) of the Lyapunov exponent, and the robust controller adjusts the gain matrix K(t) according to λ(t) to generate the control input u(t).

[0131] The control input u(t) is applied to the motion execution system of the welding device, and the state variable x(t) and welding quality index of the welding device are continuously monitored.

[0132] By working together with an adaptive estimator and a robust controller, chaotic behavior during the welding process is suppressed, thereby improving the robustness and adaptability of the motion control of the welding device.

[0133] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic pipe ring welding device, characterized in that, include: Welding rail (1), during operation, is set on the side of the pipe near the weld; The two free ends of the welding track (1) extend along the outer wall of the pipe and are wrapped around the outer wall of the pipe; A motorized component, mounted on a welding rail (1), is used to provide propulsion. Mounting bracket (4) is mounted on the motor assembly for mounting and fixing the welding unit; The mobility components include: The mounting box (3) contains an electric motor (34); The control box (31) is fixed on the outer wall of the mounting box (3). The control box (31) contains a control module for controlling the motor (34) and the welding unit. During welding, the working status of the motor and the welding unit is controlled by the control box. A power roller (36) is used to provide power for movement along the outer wall of the pipe; The welding track (1) is a strip structure. One of the free ends of the welding track (1) narrows to form an interpenetrating end. The other free end of the welding track (1) is provided with a notch for accommodating the interpenetrating end. The other free end of the welding track (1) is fixedly connected to two connecting blocks (11) located on both sides of the notch. A crossbar (12) of I-shaped structure is inserted between the two connecting blocks (11). A limiting piece (13) extending into the notch is fixed to the radial sidewall of the crossbar (12). A slot for the end of the limiting piece (13) to be engaged is opened on the sidewall of the interpenetrating end facing the limiting piece (13). Two crossbars (12) are provided, and an insertion space is provided between the two crossbars (12) for the insertion end to pass through. Two limiting pieces (13) are provided, and the ends of the two limiting pieces (13) extend to the side that is close to each other. The other side wall of the insertion end is also provided with a slot for locking the end of the other limiting piece (13). One of the connecting blocks (11) has a hollow cavity. Two crossbars (12) extend into the hollow cavity from the same end. The upper crossbar (12) is fixed with an elastic lever (14) in a C-shape structure located in the hollow cavity. The lower crossbar (12) is fixed with an extension rod (15) located in the hollow cavity. A vertical rod (16) is fixed on the upper side of the extension rod (15) near the crossbar (12). The end of the vertical rod (16) is hinged to the end of the lever. The bottom wall of the hollow cavity is fixed with a limiting seat (18), the limiting seat (18) extends upward with a limiting part, the side walls of the limiting part are arc-shaped, and elastic steel rings (19) are provided on the arc-shaped structure. The ends of the extension rod (15) are fixed with pressure blocks (17) that are respectively fixed to the outer walls of the two elastic steel rings (19). The welding track (1) contains an elastic steel sheet (5) that extends along the direction of the welding track (1) and is wound around the outer wall of the pipe. The welding track is provided with a through hole; the welding track has multiple rollers embedded in the side wall facing the pipe, and the multiple rollers (2) are divided into multiple groups, with two rollers (2) in each group, and the two rollers (2) in each group are symmetrically distributed with the elastic steel sheet (5) as the center. Each set of two rollers (2) is connected by a reinforcing plate (21) embedded in the welding track (1). The reinforcing plate (21) has a curved structure and the side wall of the reinforcing plate (21) has a snap-fit ​​interface for engaging with the elastic steel plate (5).

2. The automatic pipe ring welding device according to claim 1, characterized in that: Multiple rollers and power rollers form a power support frame that allows the welding equipment to move automatically in a ring along the outer wall of the pipe; during operation, the motorized components drive the welding track to move along the pipe as a whole.

3. The automatic pipe ring welding device according to claim 2, characterized in that: The mounting box (3) is fixed on the side wall of the welding track (1) located at the through hole. The output end of the motor (34) is connected to the gear plate (35). The mounting box (3) has a matching hole on the side wall opposite to the through hole. The power roller (36) is rotatably installed in the matching hole. The power roller (36) has a tooth groove that meshes with the gear plate (35) at one axial end.

4. The automatic pipe ring welding device according to claim 3, characterized in that: The mounting base (4) and the control box (31) are adjustablely connected. A protrusion (33) is fixed on the back side wall of the mounting base (4). A threaded adjustment rod (32) is rotatably provided on the side wall of the control box (31). The protrusion (33) has a threaded hole that is threadedly connected to the threaded adjustment rod (32). A guide groove is provided on the back side wall of the mounting base (4). A guide block that slides and engages with the guide groove is fixed on the side wall of the control box (31).

5. A ring welding method using an automatic ring welding device for pipes, implemented using any one of the automatic ring welding devices for pipes as described in claims 1 to 4, wherein the welding device is equipped with an image acquisition unit, characterized in that... Includes the following steps: Step S1: Read the pre-configured welding parameter configuration database in the control module, as well as the real-time welding image and pipeline image acquired by the image acquisition unit; and perform noise reduction, enhancement and normalization processing on the acquired images; the welding parameter configuration database is configured with the mapping relationship between pipeline curvature, welding trajectory and optimal welding parameters; Step S2: Use an edge detection method based on local adaptive threshold to identify and fit the pipe curvature, and use an image segmentation method to obtain the welding trajectory on the pipe surface to obtain the current pipe curvature and welding trajectory data; Step S3: Based on the current pipe curvature and welding trajectory data, search for the current optimal welding parameters in the welding parameter configuration database; Step S4: Compare the current optimal welding parameters with the current real-time welding parameters, and adjust the motion trajectory parameters and welding parameters of the welding unit; The process of fitting the curvature of the pipeline is further as follows: Step S21: Divide the preprocessed image into overlapping local windows of size n×n, with the center pixel coordinates of each window being (i,j); n is a natural number greater than 0, and i and j are coordinate values; Step S22: For each local window, calculate the mean μ(i,j) and standard deviation σ(i,j) of the pixel gray values ​​within the window; based on the mean and standard deviation, adaptively calculate the local threshold T(i,j) = μ(i,j) + k × σ(i,j), where k is a predefined constant; for the center pixel (i,j) of the window, if its gray value is greater than the local threshold T(i,j), then mark it as an edge point; otherwise, mark it as a non-edge point. Step S23: Slide the window and repeat step S22 until all pixels of the entire image have been processed; further refine and connect the marked edge points to obtain the final pipe edge; Step S24: Represent the detected pipe edge point set as (x i ,y i ) i＝1 N , where N is the number of edge points; for each edge point (x i ,y i Define a local neighborhood N i , including its K nearest neighbors; in the local neighborhood N i Within the boundary points, a weighted polynomial regression is performed to fit a p-th degree polynomial curve f. i (x) = a0 + a1x + ... + a p x p ; Step S25, in weighted regression, each neighborhood point (x j ,y j The weight w j Determined by the Gaussian kernel function: w j =exp(-||x j -x i || 2 / (2h 2 (), where h is the bandwidth parameter; by minimizing the weighted mean square error, the polynomial coefficients {a0, a1, ..., a p }, thus obtaining the local fitting curve f i (x); Step S26: Repeat steps S23 and S24 for all edge points to obtain a set of local fitting curves f i (x) i＝1 N The local fitted curves are combined into a global curve F(x) by weighted averaging. The global curve F(x) is then smoothed and its curvature is calculated to obtain the final curvature estimate of the pipeline.

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