Bent pipe connector forward and reverse intelligent deviation rectification virtual assembly blanking method

Abstract

The invention discloses an elbow connector forward and reverse intelligent deviation rectification virtual assembly blanking method, which comprises the following steps: carrying out 3d scanning on a new elbow and two old pipes, carrying out space matching on two axes of the new elbow and the axes of the two old pipes, searching an optimal assembly position, calculating boundary data of an annular track and extracting track deviation rectification characteristics; the track deviation correction characteristics are added into the preliminary cutting control data so as to compensate the track installation deviation when the cutting robot cuts; and generating final cutting control data. The device has the beneficial effects that a new bent pipe and an old pipe are scanned in a handheld 3d mode, point cloud data are recognized, a cutting route is simulated, final cutting control data, the walking route for controlling the cutting robot and control data for controlling the cutting torch to move on the sliding rail are obtained, automatic cutting is achieved in cooperation with the cutting robot, and the cutting efficiency is improved. Therefore, data support is provided for efficiently completing pipeline first-aid repair.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline maintenance, and in particular to a method for virtual grouping and cutting of pipe elbow joints with forward and reverse intelligent deviation correction. Background Art

[0002] When oil and gas pipelines, for example, are damaged and require emergency repair or rerouting, they often encounter the problem of a dead end. Emergency repair procedures typically involve cold cutting the damaged old pipe, leaving two sections. A new straight or curved pipe is then welded to the ends of the old pipe. After the old pipe is cut, it often misaligns due to stress, causing the axes of the two ends to intersect in any spatial position, creating a dead end. Traditional repair techniques first determine the spacing between the two old pipes. A new pipe (straight or curved, depending on the requirement) is then taken that meets this spacing. The new pipe is then cut (called forward cutting) or the old pipe (called reverse cutting). The new and old pipes are then aligned, and the cut line and angle of the new pipe are manually confirmed. After cutting, the ends are welded to complete the repair. Traditional repair techniques require experienced operators to make repeated adjustments, resulting in uneven gaps between the new and old pipes, inefficiencies, and prolonged repair times.

[0003] The traditional straight pipe’s dead end cutting is relatively simple, and pipe workers have mature measurement methods, generally using manual measurement, manual marking and cutting. However, the measurement of the dead end of the bent pipe is more complicated. First, due to the large dimensions of the bent pipe, which can be as short as a few meters or as long as more than ten meters, the longer the distance, the more difficult the measurement; second, in order to improve the measurement accuracy, it is often necessary to calibrate the new bent pipe horizontally, polish the pipe mouth, and other actions, and the whole process is very time-consuming; third, when measuring old pipes, it is relatively difficult to measure accurately due to problems such as the large scale; due to the above reasons, how to improve the measurement speed of the dead end of the bent pipe and how to use intelligent equipment to assist manual cutting during special hot work repair operations have become urgent needs for pipeline network repairs. There are two cutting methods for intelligent cutting: Forward Cutting: Intelligent cutting of the finished material involves cutting the straight sections (sleeves) at both ends of the new elbow. A track is installed above the sleeves. The cutting robot travels along the track in a single circle. After cutting, the ends of the new elbow form a spatial trajectory, with the inner diameter trajectory curve forming a matching curve. The two ends of the old pipe, however, are cut using a different method, typically forming a perfect circle, and their inner diameter curve also forms a matching curve.

[0004] Reverse cutting: New pipe bends are prefabricated, typically with two perfectly round ends and a matching inner diameter curve. For intelligent cutting of old pipes, a track is installed on the old pipe, and the cutting robot moves along the track in a circle. After cutting, the two ends of the old pipe form a spatial trajectory, and the inner diameter trajectory curve is a matching inner diameter curve. Summary of the Invention

[0005] The object of the present invention is to provide a method for virtual grouping and cutting of elbow joints with intelligent forward and reverse deviation correction, which solves or partially solves the above-mentioned technical problems.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for cutting pipe elbows in forward and reverse directions with intelligent deviation correction and virtual pairing, comprising forward cutting or reverse cutting, including the following steps: S1. 3D Data Acquisition: 3D scans are performed on the new bend and two sections of the old pipe to obtain point cloud data. The pipe shape recognition module analyzes the point cloud data to extract spatial position information for the new and old pipes, including the cylinder's diameter, axis, end face geometry, and spatial orientation angle. S2. Spatial Matching: Spatially align the axes of the new elbow with the axes of the two old pipe sections. Adjust the new elbow's position to achieve the optimal assembly position. Ensure that the axes of the new elbow intersect with the axes of the old pipe with an inclination of less than 3 degrees. Determine the intersection line between the new elbow and the two old pipe sections. S3. Deviation Compensation and Cutting Control: The cutting robot and cutting torch are mounted on a circular track. Based on the point cloud data from step S1 and the intersection line from step S2, final cutting control data including deviation compensation is generated. This final cutting control data is used to control the circumferential movement of the cutting robot along the new or old pipe bend and to dynamically control the axial movement of the cutting torch along the new or old pipe bend using the outer boundary data of the circular track. The step of extracting cylindrical information by the tube shape recognition module includes: S11. Axis Estimation: Use principal component analysis to determine the principal component directions of the point cloud data, which serve as the preliminary axis directions of the cylinder. Calculate the point cloud centroid and construct a preliminary axis based on the preliminary axis directions. S12. Parameter Optimization: Establish a coordinate system based on the preliminary axis and construct the objective function based on the input pipe outer diameter. Use a nonlinear least squares optimization method to determine the precise axis parameters.

[0007] Preferably, the tube shape recognition module further includes: S13. Noise Removal: Create a projection plane perpendicular to the cylinder axis and project the point cloud data onto the projection plane. Identify the outer circle or inner circle on the projection surface that matches the outer diameter / inner diameter of the input pipe, and remove noise points outside the outer circle / inner circle.

[0008] Preferably, the difference between forward blanking and reverse blanking includes: Forward cutting: The cutting object is a new curved pipe; the cutting trajectory is along the circumference of the new curved pipe, and the cutting torch moves along the axial direction of the new curved pipe to perform correction compensation; Reverse cutting: The cutting object is the old pipe; the cutting trajectory is along the circumference of the old pipe, and the cutting torch moves along the axial direction of the old pipe to perform deviation correction and compensation.

[0009] Preferably, the method further includes step S4. Virtual pairing verification: virtualizing the connection state of the new elbow and the old pipe in the same coordinate system, manually adjusting the virtual pairing effect, and generating final cutting control data; The virtual group pair verification step includes: Construct virtual models of the new elbow and the old pipe in 3D modeling software; Adjust the spatial position of the new elbow by interactively dragging to simulate the actual pairing state; Verify the feasibility of the final cutting control data and output error correction parameters.

[0010] Preferably, the cutting robot comprises: The running wheels run along the circular track, and the outer side of the running wheels is provided with a rib for clamping the edge of the circular track; A slide rail is arranged along the axial direction of the pipeline, and a cutting torch is movably mounted on the slide rail. The movement of the cutting torch is controlled by a control module.

[0011] The beneficial effects of the present invention include: using a handheld or fixed 3D scanning device to scan new and old pipes, identifying the point cloud data, and simulating the welding path to obtain final cutting control data. This data controls the cutting robot's travel path and the movement of the cutting torch on the slide rail, allowing the cutting robot to automatically cut, thereby efficiently completing pipeline repairs. The final cutting control data includes compensation for installation deviations of the circular track edge and deviations of the cutting torch, thereby improving cutting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the present invention when feeding forward; Figure 2 This is a schematic diagram of the reverse blanking process of the present invention; Figure 3 It is a schematic structural diagram of the cutting robot of the present invention; Figure 4 This is a process flow chart of the forward feeding method of the present invention; Figure 5 This is a diagram of the calculation steps for forward feeding of the present invention; Figure 6 It is a process flow chart of reverse blanking of the present invention; Figure 7 This is a schematic diagram of the spatial matching between the new pipe and the old pipe. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be further described in detail below in conjunction with specific implementation methods.

[0014] In the description of the present invention, it should be noted that the terms "inside", "outside", "up", "down", "horizontal", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limiting the present invention.

[0015] like Figures 1 to 7 As shown, a virtual pairing and cutting method for intelligently correcting the forward and reverse directions of a bend pipe joint of the present invention is a virtual pairing and cutting method for reconnecting two sections of old pipe 20 in a dead end state with a new bend pipe 10; it uses a cutting robot 12 designed by the applicant (specific structure reference patent 2009101950034) to cut the pipe, the cutting robot 12 walks on a circular track 14, the circular track 14 surrounds the pipe to be cut, the cutting robot 12 is provided with a slide rail 16 along the axial direction of the pipe to be cut, and a cutting torch 18 for cutting the pipe is movably provided on the slide rail 16; and it also includes a control module (not shown) that controls the movement of the cutting robot 12 and the cutting torch 18. The cutting robot 12 has several wheels 22 on both sides that travel on a circular track 14. Each wheel 22 is equipped with a rib 24 on its outer side to grip the outer edge of the track 14. The rib 24 acts as a stop, ensuring that the wheels 22 do not deviate from the track 14 during travel. The path of the wheels 22 after completing one orbit around the track 14 is highly aligned with the track's edge, facilitating precise compensation later. A slide rail 16 is provided on the cutting robot 12 along the axis of the pipe to be cut. A cutting torch 18 is movably mounted on the slide rail 16. An electric cylinder (not shown) or servo motor drives the cutting torch 18.

[0016] Taking forward cutting (i.e. cutting a new elbow 10 or a sleeve of the new elbow 10, with two old pipes 20 pre-cut into perfect circles in a direction perpendicular to their own axes) as an example, the present invention includes the following steps: S1. 3D Data Acquisition: 3D scans of the new curved pipe 10 and two sections of the old pipe 20 are performed using a handheld or fixed scanning device to obtain point cloud data. The pipe shape recognition module analyzes the point cloud data to extract spatial position information for the new curved pipe 10 and the old pipe 20, including the cylinder's diameter, axis, end face geometry, and spatial orientation angle. The above cylindrical information, namely the positional relationship between the new bent pipe 10 and the two sections of old pipe 20 in the same spatial coordinate system, provides data for subsequent virtual pairing (that is, simulated pairing in the system); the axes of the two sections of old pipe 20 can be in the same plane or staggered in space, that is, a dead end state.

[0017] S2. Spatial matching: The axes of the new pipe 10 at both ends are spatially aligned with the axes of the two old pipe sections 20. The new pipe 10 is adjusted to achieve the optimal assembly position, ensuring that the axes of the new pipe 10 at both ends intersect with the axes of the old pipe 20 with an inclination of less than 3 degrees. The intersection line between the new pipe 10 and the two old pipe sections 20 is determined. During the adjustment process, the axes of the new pipe 10 and the two old pipe sections 20 must always intersect and partially overlap to achieve the optimal assembly position. S3. Deviation Compensation and Cutting Control: Install circular track 14 onto the new curved pipe 10. Install cutting robot 12 and cutting torch 18 on circular track 14. Generate final cutting control data including deviation compensation based on the point cloud data from step S1 and the intersection line from step S2. This final cutting control data is used to control the circumferential movement of cutting robot 12 along the new curved pipe 10 and dynamically control the axial movement of cutting torch 18 along the new curved pipe 10 using data from the outer boundary of circular track 14. The step of extracting cylindrical information by the tube shape recognition module includes: S11. Axis Estimation: Use principal component analysis (PCA) to determine the principal component directions of the point cloud data, which serve as the preliminary axis directions for the cylinder. Calculate the point cloud centroid and construct a preliminary axis based on these preliminary axis directions. Principal component analysis (PCA) of point cloud data is a commonly used dimensionality reduction and feature extraction method for analyzing the spatial distribution characteristics of point clouds (such as direction and shape). S12. Parameter Optimization: Establish a coordinate system based on the preliminary axis and construct the objective function based on the input pipe outer diameter. Use a nonlinear least squares optimization method to determine the precise axis parameters.

[0018] S13. Noise Removal: Create a projection plane perpendicular to the cylinder axis and project the point cloud data onto the projection plane. Identify the outer circle or inner circle on the projection surface that matches the outer diameter / inner diameter of the input pipe, and remove noise points outside the outer circle / inner circle.

[0019] The above method is a simple and easy method for extracting cylinder information, which has a small amount of calculation and a fast calculation speed, and is suitable for the use scenario of the present invention.

[0020] The present invention also includes: Step S4. Virtual pair verification: Virtually verify the connection status of the new elbow 10 and the old pipe 20 in the same coordinate system, manually adjust the virtual pairing effect, and generate the final cutting control data; The virtual pair verification steps include: Constructing virtual models of the new elbow 10 and the old pipe 20 in a three-dimensional modeling software; Adjust the spatial position of the new elbow 10 by interactive dragging to simulate the actual pairing state; Verify the feasibility of the final cutting control data and output error correction parameters. It can be manually debugged on the computer to obtain the group results and simplify the calculation.

[0021] S5. The final cutting control data is imported into the control module via the USB interface, and the cutting torch 18 is ignited. The control module then controls the cutting robot 12 to orbit along the circular track 14 according to the final cutting control data, while simultaneously controlling the cutting torch 18 to perform correction feature compensation, thus completing the complete cutting of the pipe to be cut. The cut new bend 10 is then handed over to the operator for alignment, fixing, and welding based on the matching markings of the new bend 10 and the old pipe 20.

[0022] The present invention also includes a reverse cutting method: the cutting operation includes installing the circular track 14 on two old pipes 20, and then installing the cutting robot 12 on the circular track 14 to cut the old pipes 20, and the other steps are the same as before.

[0023] As shown in the attached drawings, in terms of the operational process, when reverse cutting, the new bend 10 does not need to be cut, so the scanning data can be completed in advance; for forward cutting, the slide rail 16, cutting torch 18, and new bend 10 can be set up in advance and the scanning data can be completed in advance; the new bend 10 also does not need to be polished in section, which further saves the process. This adjustment of the operating steps can greatly improve the efficiency of the pipe workers and reduce the operating window for emergency repair operations with a small time window. At present, there is no reverse cutting processing method in the industry, and the focus is on the forward cutting operation method. Compared with forward cutting, reverse cutting takes less time and is more efficient. The structure of the cutting robot 12 of the present invention makes its walking trajectory close to the circular track 14. After obtaining the data of the edge of the circular track 14 from the point cloud data, the deviation of the circular track 14 caused by installation and other reasons can be compensated, thereby obtaining a more accurate cutting surface.

[0024] Compared to straight pipe cutting, where the cutting target is a single straight pipe with a single axis, the two cutting torches move along the pipe axis, requiring only one dimension to consider, making the process simpler. However, the present invention addresses the processing of newly curved pipes 10, which have two axes in different directions, making the process more complex.

[0025] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for virtual pairing and blanking of pipe elbows with intelligent forward and reverse deviation correction, which includes forward blanking or reverse blanking, characterized in that: The following steps are involved: S1. 3D Data Acquisition: 3D scans are performed on the new bend and two sections of the old pipe to obtain point cloud data. The pipe shape recognition module analyzes the point cloud data to extract spatial position information for the new and old pipes, including the cylinder's diameter, axis, end face geometry, and spatial orientation angle. S2. Spatial Matching: Spatially align the axes of the new elbow with the axes of the two old pipe sections. Adjust the new elbow's position to achieve the optimal assembly position. Ensure that the axes of the new elbow intersect with the axes of the old pipe with an inclination of less than 3 degrees. Determine the intersection line between the new elbow and the two old pipe sections. S3. Deviation Compensation and Cutting Control: The cutting robot and cutting torch are mounted on a circular track. Based on the point cloud data from step S1 and the intersection line from step S2, final cutting control data including deviation compensation is generated. This final cutting control data is used to control the circumferential movement of the cutting robot along the new or old pipe bend and to dynamically control the axial movement of the cutting torch along the new or old pipe bend using the outer boundary data of the circular track. The step of extracting cylindrical information by the tube shape recognition module includes: S11. Axis Estimation: Use principal component analysis to determine the principal component directions of the point cloud data, which serve as the preliminary axis directions of the cylinder. Calculate the point cloud centroid and construct a preliminary axis based on the preliminary axis directions. S12. Parameter Optimization: Establish a coordinate system based on the preliminary axis and construct the objective function based on the input pipe outer diameter. Use a nonlinear least squares optimization method to determine the precise axis parameters.

2. The method according to claim 1, characterized in that The tube shape recognition module further includes: S13. Noise Removal: Create a projection plane perpendicular to the cylinder axis and project the point cloud data onto the projection plane. Identify the outer circle or inner circle on the projection surface that matches the outer diameter / inner diameter of the input pipe, and remove noise points outside the outer circle / inner circle.

3. The method according to claim 1, characterized in that The differences between forward blanking and reverse blanking include: Forward cutting: The cutting object is a new curved pipe; the cutting trajectory is along the circumference of the new curved pipe, and the cutting torch moves along the axial direction of the new curved pipe to perform correction compensation; Reverse cutting: The cutting object is the old pipe; the cutting trajectory is along the circumference of the old pipe, and the cutting torch moves along the axial direction of the old pipe to perform deviation correction and compensation.

4. The method according to claim 1, wherein The process also includes step S4. Virtual pairing verification: virtualizing the connection between the new elbow and the old pipe in the same coordinate system, manually adjusting the virtual pairing effect, and generating final cutting control data. The virtual group pair verification step includes: Construct virtual models of the new elbow and the old pipe in 3D modeling software; Adjust the spatial position of the new elbow by interactively dragging to simulate the actual pairing state; Verify the feasibility of the final cutting control data and output error correction parameters.

5. The method according to claim 1, characterized in that The cutting robot comprises: The running wheels run along the circular track, and the outer side of the running wheels is provided with a rib for clamping the edge of the circular track; A slide rail is arranged along the axial direction of the pipeline, and a cutting torch is movably mounted on the slide rail. The movement of the cutting torch is controlled by a control module.

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