A virtual group correction method for forward and reverse intelligent correction of elbow joint

Abstract

The application discloses a method for virtual group correction of a bend pipe joint, which comprises the following steps: 3D scanning of a new bend pipe and two old pipes, spatial matching of two axis lines of the new bend pipe with two axis lines of the two old pipes, searching for an optimal assembly position, calculating boundary data of a ring track and extracting track correction features, adding the track correction features to the above-mentioned preliminary cutting control data, compensating for track installation deviation when a cutting robot cuts, and generating final cutting control data. The application has the following beneficial effects: handheld 3D scanning of the new bend pipe and the old pipes, identification of point cloud data, simulation of a cutting route, acquisition of final cutting control data, control of a walking route of the cutting robot and control data of movement of a cutting torch on a sliding rail, automatic cutting of the cutting robot, and provision of data support for efficient completion of pipeline repair.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline repair, and particularly relates to a virtual group alignment unloading method for a straight pipe joint. BACKGROUND

[0002] When a damaged oil or gas pipeline needs to be repaired or the pipeline needs to be relocated, the problem of a dead end will be encountered. The repair process usually involves cutting the damaged old pipeline by cold cutting, leaving two sections of the pipeline, and then welding a new straight pipe or a new elbow pipe to the two ends of the old pipeline. After the old pipeline is cut, it will usually be misaligned due to stress, causing the two ends to be staggered in any spatial position, which is a dead end. In the traditional repair process, the distance between the two old pipelines is first determined, and then a new pipeline (either a straight pipe or an elbow pipe) that is longer than the distance is selected. The new pipeline is then cut (referred to as forward unloading) or the old pipeline is cut (referred to as reverse unloading). The new pipeline and the old pipeline are adjusted, and the cutting line and the angle of the new pipeline are manually confirmed. After cutting, the two ends are welded to complete the repair work. The traditional repair process requires experienced operators to make repeated adjustments, and the gap between the new and old pipelines is uneven, resulting in low efficiency and prolonging the repair time.

[0003] The traditional dead end unloading and cutting of a straight pipe is relatively simple, and pipe workers have a mature measurement method, which generally involves manual measurement, manual marking, and cutting. However, the measurement of a dead end of an elbow pipe is more complex. First, the size of an elbow pipe is large, with a length of a few meters to over ten meters, making it difficult to measure over long distances. Second, in order to improve measurement accuracy, the new elbow pipe often needs to be horizontally calibrated and the pipe opening needs to be polished, which consumes a lot of time. Third, it is relatively difficult to accurately measure the old pipeline due to its large size. Due to the above reasons, during a special fire repair operation, it is urgent to improve the measurement speed of the dead end of the elbow pipe and to use intelligent equipment to assist manual cutting. There are two cutting methods for intelligent cutting:

[0004] Forward unloading: the intelligent cutting is performed on the straight pipe sections (sleeves) at both ends of the new elbow pipe. The track is installed on the sleeves. The cutting robot runs along the track. After cutting, the two ends of the new elbow pipe form a spatial trajectory, and the inner diameter trajectory curve is a matching curve. The two pipe openings of the old pipeline are cut in other ways, generally as a right circular opening, and the inner diameter curve is a matching curve.

[0005] Reverse unloading: the new elbow pipe is a pre-fabricated elbow pipe, and the two ports are generally right circular openings with an inner diameter curve that is a matching curve. The old pipeline is cut by intelligent cutting. The track is installed on the old pipeline, and the cutting robot runs along the track. After cutting, the two pipe openings of the old pipeline form a spatial trajectory, and the inner diameter trajectory curve is a matching curve. SUMMARY

[0006] The present application aims to provide a pipe jointing positive and reverse intelligent deviation correction virtual group pairing cutting method to solve or partially solve the above technical problems.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0008] A pipe jointing positive and reverse intelligent deviation correction virtual group pairing cutting method, comprising positive cutting or reverse cutting, comprising the following steps:

[0009] S1. Three-dimensional data acquisition: 3D scanning of a new pipe and two old pipes to obtain point cloud data; analyzing the point cloud data through a pipe shape identification module to extract the spatial position information of the new pipe and the old pipes, including the diameter, axis, end face circle geometric information and spatial attitude angle of the cylinder;

[0010] S2. Spatial matching: spatially matching the axes of the two ends of the new pipe with the axes of the two old pipes, adjusting the attitude of the new pipe to obtain the best assembly position, ensuring that the axes of the two ends of the new pipe intersect with the axes of the old pipes and the inclination is less than 3 degrees, and obtaining the intersection lines of the new pipe and the two old pipes;

[0011] S3. Deviation correction and compensation and cutting control: installing a cutting robot and a cutting torch on a ring track, generating final cutting control data containing deviation correction and compensation based on the point cloud data of step S1 and the intersection lines of step S2, the final cutting control data being used to control the cutting robot to move circumferentially along the new pipe or the old pipe and dynamically control the cutting torch to move axially along the new pipe or the old pipe through the outer boundary data of the ring track;

[0012] The pipe shape identification module extracts the cylinder information, which comprises:

[0013] S11. Axis estimation: determining the principal component direction of the point cloud data through principal component analysis as the preliminary axis direction of the cylinder; calculating the point cloud centroid and constructing the preliminary axis in combination with the preliminary axis direction;

[0014] S12. Parameter optimization: establishing a coordinate system based on the preliminary axis, and constructing a target function in combination with the input pipe outer diameter; solving the accurate axis parameters by using a nonlinear least squares optimization method.

[0015] Preferably, the pipe shape identification module further comprises:

[0016] S13. Noise elimination: establishing a projection plane perpendicular to the axis of the cylinder, and projecting the point cloud data to the projection plane;

[0017] Identifying the outer circle or inner circle that meets the input pipe outer diameter / inner diameter on the projection plane, and eliminating the noise points outside the outer circle / inner circle.

[0018] Preferably, the difference between the forward blanking and the reverse blanking includes:

[0019] Forward blanking: the cutting object is a new bend pipe; the cutting track is along the circumferential direction of the new bend pipe, and the cutting torch moves along the axial direction of the new bend pipe to compensate for the deviation;

[0020] Reverse blanking: the cutting object is an old pipe; the cutting track is along the circumferential direction of the old pipe, and the cutting torch moves along the axial direction of the old pipe to compensate for the deviation.

[0021] Preferably, it further includes step S4. Virtual group verification: verifying the feasibility of the final cutting control data and outputting error correction parameters by manually adjusting the virtual group effect under the connection state of the virtual new bend pipe and the old pipe in the same coordinate system;

[0022] The virtual group verification step includes:

[0023] Constructing virtual models of the new bend pipe and the old pipe in a three-dimensional modeling software;

[0024] Adjusting the spatial position of the new bend pipe through interactive dragging to simulate the actual group state;

[0025] Verifying the feasibility of the final cutting control data and outputting error correction parameters.

[0026] Preferably, the cutting robot includes:

[0027] A walking wheel walking along the annular track, and a stop edge arranged outside the walking wheel to clamp the edge of the annular track;

[0028] A slide rail arranged along the axial direction of the pipe, and a cutting torch movably installed on the slide rail, wherein the movement of the cutting torch is controlled by a control module.

[0029] The beneficial effects of the present application are: using a handheld or fixed 3D scanning device to scan the new bend pipe and the old pipe, identifying the point cloud data, simulating the welding route, obtaining the final cutting control data, controlling the walking route of the cutting robot and the control data of the movement of the cutting torch on the slide rail, and cooperating with the cutting robot to automatically cut, thereby efficiently completing the pipeline repair. The final cutting control data includes the installation deviation of the edge of the annular track and the deviation compensation of the cutting torch, thereby improving the cutting quality. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a physical schematic diagram of the forward blanking of the present application;

[0031] Figure 2 is a physical schematic diagram of the reverse blanking of the present application;

[0032] Figure 3 is a structural schematic diagram of the cutting robot of the present application;

[0033] Figure 4 is the process flow chart of the positive downfeed of the present application;

[0034] Figure 5 is the calculation step chart of the positive downfeed of the present application;

[0035] Figure 6 is the process flow chart of the reverse downfeed of the present application;

[0036] Figure 7 is the schematic diagram of the space matching of the new pipe and the old pipe. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be further described in detail in combination with the specific embodiments.

[0038] In the description of the present application, it should be noted that the terms "inner", "outer", "upper", "lower", "horizontal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0039] As shown in Figures 1 to 7 , the positive and reverse intelligent deviation correction virtual group downfeed method for pipe joint connection of the present application is a virtual group downfeed method for reconnecting two sections of old pipe 20 in a dead corner state with a new pipe 10; a cutting robot 12 designed by the applicant (for specific structure, refer to patent 2009101950034) is used for pipe cutting, the cutting robot 12 walks on a ring track 14, the ring track 14 is wrapped around the pipe to be cut, a slide rail 16 is arranged axially along the pipe to be cut on the cutting robot 12, a cutting torch 18 for cutting the pipe is movably arranged on the slide rail 16; and a control module (not shown) for controlling the movement of the cutting robot 12 and the cutting torch 18 is further included. The cutting robot 12 has a plurality of walking wheels 22 on both sides for walking on the ring track 14, a stop edge 24 for clamping the outer edge of the ring track 14 is arranged on the outer side of each walking wheel 22; based on the limiting action of the stop edge 24, the walking wheels 22 can not deviate from the ring track 14 when walking, and the trajectory of one round of the walking wheels 22 on the ring track 14 is consistent with the edge height of the ring track 14, so as to facilitate accurate compensation in the later stage. A slide rail 16 is arranged axially along the pipe to be cut on the cutting robot 12, a cutting torch 18 is movably arranged on the slide rail 16, and an electric cylinder (not shown) or a servo motor is arranged on the cutting robot 12 to drive the cutting torch 18.

[0040] Taking the forward blanking (i.e. cutting a new elbow pipe 10 or a sleeve of the new elbow pipe 10, and two old pipes 20 being cut into a perfect circle in a direction perpendicular to their own axes) as an example, the present application comprises the following steps:

[0041] S1. Three-dimensional data acquisition: 3D scanning of the new elbow pipe 10 and the two old pipes 20 is performed by a handheld or fixed scanning device to obtain point cloud data thereof; a pipe shape recognition module is used to analyze the point cloud data and extract spatial position information of the new elbow pipe 10 and the old pipes 20, including the diameter, axis, end face circle geometric information and spatial attitude angle of the cylinder;

[0042] The above-mentioned cylinder information, i.e. the positional relationship of the new elbow pipe 10 and the two old pipes 20 in the same spatial coordinate system, provides data for subsequent virtual assembly (i.e. simulation of assembly in the system); the axes of the two old pipes 20 can be in the same plane or staggered in space, i.e. in a dead-end state.

[0043] S2. Spatial matching: the axes of the two ends of the new elbow pipe 10 are respectively matched with the axes of the two old pipes 20 in space, the attitude of the new elbow pipe 10 is adjusted to obtain the best assembly position, and it is ensured that the axes of the two ends of the new elbow pipe 10 intersect with the axes of the old pipes 20 and the inclination is less than 3 degrees, and the intersection line of the new elbow pipe 10 and the two old pipes 20 is obtained; during the adjustment process, it is necessary to ensure that the two axes of the new elbow pipe 10 always intersect with the axes of the two old pipes 20 and partially overlap to form the best assembly position;

[0044] S3. Deviation correction compensation and cutting control: the annular track 14 is installed on the new elbow pipe 10, the cutting robot 12 and the cutting torch 18 are installed on the annular track 14, the final cutting control data containing deviation correction compensation are generated based on the point cloud data of step S1 and the intersection line of step S2, and the final cutting control data are used to control the cutting robot 12 to move along the circumference of the new elbow pipe 10 and dynamically control the cutting torch 18 to move along the axis of the new elbow pipe 10 through the outer boundary data of the annular track 14;

[0045] The step of extracting cylinder information by the pipe shape recognition module comprises:

[0046] S11. Axis estimation: the principal component direction of the point cloud data is determined by principal component analysis as the preliminary axis direction of the cylinder; the point cloud centroid is calculated, and a preliminary axis is constructed in combination with the preliminary axis direction; the principal component analysis (PCA) of the point cloud data is a commonly used dimension reduction and feature extraction method, which is used to analyze the spatial distribution characteristics (such as direction, shape, etc.) of the point cloud;

[0047] S12. Parameter optimization: a coordinate system is established based on the preliminary axis, and a target function is constructed in combination with the input pipe outer diameter; the nonlinear least squares optimization method is used to solve the accurate axis parameters.

[0048] S13. Noise elimination: a projection plane perpendicular to the axis of the cylinder is established, and the point cloud data is projected onto the projection plane;

[0049] Identify the outer circle or inner circle on the projection plane that meets the outer diameter / inner diameter of the input pipe, and eliminate noise points outside the outer circle / inner circle.

[0050] The above method is a simple and easy method for extracting cylindrical information, which has small calculation amount and fast calculation speed, and is suitable for the use scene of the application.

[0051] The application also includes:

[0052] Step S4. Virtual group verification: verify the connection state of the new elbow pipe 10 and the old pipe 20 in the same coordinate system, manually adjust the virtual group effect, verify the feasibility of the final cutting control data, and output error correction parameters;

[0053] The virtual group verification step includes:

[0054] Constructing a virtual model of the new elbow pipe 10 and the old pipe 20 in a three-dimensional modeling software;

[0055] Adjust the spatial position of the new elbow pipe 10 by interactive dragging to simulate the actual group state;

[0056] 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 result and simplify the calculation.

[0057] S5. Import the final cutting control data into the control module through the USB interface, ignite the cutting torch 18, and control the cutting robot 12 to rotate around the ring track 14 according to the final cutting control data, while controlling the cutting torch 18 to perform deviation correction compensation, complete the complete cutting of the pipe to be cut. The new elbow pipe 10 cut down is handed over to the operator to align and group according to the alignment mark of the new elbow pipe 10 and the old pipe 20, fixed and welded.

[0058] The application also includes a reverse blanking method: the cutting operation includes installing the ring track 14 on the two old pipes 20, and then installing the cutting robot 12 on the ring track 14 to cut the old pipes 20, and the other steps are the same as before.

[0059] As shown in the drawings, in terms of operation flow, the new bend pipe 10 can complete scanning data in advance due to no need of cutting during reverse unloading; for forward unloading, the slide rail 16, cutting torch 18 and new bend pipe 10 can be erected in advance and scanning data can be completed in advance; the new bend pipe 10 also does not need to be polished in cross section, further saving process. The adjustment of the operation steps can greatly improve the operation efficiency of the pipe worker and reduce the operation window period for the repair operation with a small time window period. There is no reverse unloading processing method in the industry at present, and the current operation mode is concentrated on forward unloading. Compared with forward unloading, reverse unloading requires less time and is more efficient. The structure of the cutting robot 12 of the present application makes its walking track close to the annular track 14. After obtaining the data of the edge of the annular track 14 from the point cloud data, the deviation of the annular track 14 caused by installation and other reasons can be compensated, so as to obtain a more accurate cutting surface.

[0060] Compared with the unloading of straight pipes, the cutting object is a single straight pipe, that is, there is an axis direction, and two cutting torches move along the pipe axis direction. Only one-dimensional influencing factors need to be considered, and it is simple. The present application is for the processing process of the new bend pipe 10, which has two different direction axes, and is more complex to process.

[0061] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A virtual group of a pipe elbow joint forward and reverse intelligent deviation correction blanking method, comprising forward blanking or reverse blanking, characterized in that, The method comprises the following steps: S1. Three-dimensional data acquisition: 3D scanning is performed on the new elbow pipe and the two old pipes to obtain point cloud data; the point cloud data is analyzed by a pipe shape identification module to extract the spatial position information of the new elbow pipe and the old pipes, including the diameter, axis, end face circle geometric information and spatial attitude angle of the cylinder; S2. Spatial matching: the axes of the two ends of the new elbow pipe are respectively matched with the axes of the two old pipes in space, the attitude of the new elbow pipe is adjusted to obtain the best assembly position, and it is ensured that the axes of the two ends of the new elbow pipe and the axes of the old pipes intersect and the inclination is less than 3 degrees, and the intersection lines of the new elbow pipe and the two old pipes are obtained; S3. Deviation correction compensation and cutting control: a cutting robot and a cutting torch are installed along the annular track, based on the point cloud data of step S1 and the intersection lines of step S2, final cutting control data containing deviation correction compensation are generated, and the final cutting control data are used to control the cutting robot to move along the circumference of the new elbow pipe or the old pipe and to dynamically control the cutting torch to move along the axis of the new elbow pipe or the old pipe through the outside boundary data of the annular track; The step of analyzing the point cloud data by the pipe shape identification module to extract the spatial position information of the new elbow pipe and the old pipes comprises: S11. Axis estimation: the principal component direction of the point cloud data is determined by principal component analysis as the preliminary axis direction of the cylinder; the point cloud centroid is calculated, and a preliminary axis is constructed in combination with the preliminary axis direction; S12. Parameter optimization: a coordinate system is established based on the preliminary axis, and a target function is constructed in combination with the input pipe outer diameter; a nonlinear least squares optimization method is used to solve the accurate axis parameters; S13. Noise removal: a projection plane perpendicular to the axis of the cylinder is established, and the point cloud data is projected onto the projection plane; The outer circle or the inner circle conforming to the input pipe outer diameter / inner diameter on the projection plane is identified, and the noise points other than the outer circle / inner circle are removed; S4. Virtual group verification: the connection state of the new elbow pipe and the old pipes is virtually verified in the same coordinate system, the virtual group effect is manually adjusted, the feasibility of the final cutting control data is verified, and error correction parameters are output; The virtual group verification step comprises: A virtual model of the new elbow pipe and the old pipes is constructed in a three-dimensional modeling software; The spatial position of the new elbow pipe is adjusted by interactive dragging to simulate the actual group state; The feasibility of the final cutting control data is verified, and error correction parameters are output; S5. The final cutting control data are imported into a control module through a USB interface, the cutting torch is ignited, and the control module controls the cutting robot to complete the complete cutting of the pipe to be cut by rotating around the annular track according to the final cutting control data; The difference between the forward cutting and the reverse cutting comprises: Forward cutting: the cutting object is the new elbow pipe; the cutting track is along the circumferential direction of the new elbow pipe, and the cutting torch moves along the axial direction of the new elbow pipe for deviation correction compensation; Reverse cutting: the cutting object is the old pipe; the cutting track is along the circumferential direction of the old pipe, and the cutting torch moves along the axial direction of the old pipe for deviation correction compensation.

2. The method of claim 1, wherein, The cutting robot comprises: A walking wheel that walks along the annular track, and a stop edge that clamps the edge of the annular track is arranged outside the walking wheel; A slide rail is arranged along the axial direction of the pipe, and a cutting torch is movably installed on the slide rail, and the movement of the cutting torch is controlled by the control module in linkage.

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