Probing type pipe fitting inner wall welding seam positioning device

Abstract

The invention discloses a probing type pipe fitting inner wall welding seam positioning device which comprises a cylindrical shell and a conical shell, the conical shell is arranged at one end of the cylindrical shell, and an annular laser and an optical camera are arranged on the conical shell so as to position a pipeline inner wall welding seam; the cylindrical shell is connected with the right-angle fixing support, and the cylindrical shell is installed through the right-angle fixing support. The optical camera is installed on the conical shell through a camera support, and the camera support is used for adjusting the pitching angle of the optical camera through a C-shaped sliding groove and a camera support positioning pin. According to the probing type pipe fitting inner wall welding seam positioning device, after the angle of the camera is fixed, welding seam detection can be conducted on pipelines within a certain inner diameter range, the C-shaped sliding groove is connected to the tail of the camera so as to adjust the pitching angle of the camera, and the detection range can be adjusted; due to the flexibility, the equipment can be widely applied to pipeline welding seam detection occasions with various inner diameter ranges.

Description

Technical Field

[0001] The invention belongs to the field of offshore oil engineering and wind power engineering pipe frame construction, and in particular relates to an exploratory pipe inner wall weld positioning device. Background Art

[0002] Fixed offshore oil platforms or wind power platforms cannot do without the jacket. The jacket is equivalent to the "base" that holds the huge platform above the sea. The traditional process of jacket construction is to first prefabricate the jacket legs (main pipes) and tie pipes (branch pipes) as a whole, and then perform spatial assembly and welding of the main pipes and branch pipes with the cooperation of multiple large crawler cranes.

[0003] This high-space pairing process occupies a lot of equipment, is difficult to operate, and has a high risk factor. After exploration, it was proposed to miniaturize the main pipe and branch pipe segments, and turn the end positions that need to be paired into standardized nodes (the combination of the main pipe and the branch pipe). The nodes are prefabricated in the workshop first, and the high-altitude pairing becomes a node-based main pipe and branch pipe extension, which solves the above problems. After the nodes are miniaturized and standardized, automated manufacturing becomes possible. Both automated pairing and welding devices need to use the weld of the main pipe as the reference baseline during the node prefabrication process. Therefore, digital detection of pipe fitting welds has become an urgent problem to be solved.

[0004] Therefore, it is urgent to design a probe-type pipe inner wall weld positioning device to solve the problem of digital detection of pipe welds mentioned above. Summary of the invention

[0005] In order to solve the technical problem mentioned in the background technology that both the automated assembly and welding devices need to use the weld of the main pipe as the reference baseline in the node prefabrication process, and the pipe welds need to be digitally detected, a probe-type pipe inner wall weld positioning device is provided to solve the problem of digital detection of pipe welds.

[0006] To achieve the above-mentioned purpose, the specific technical scheme of the probe-type pipe inner wall weld positioning device of the present invention is as follows: A probe-type pipe inner wall weld positioning device comprises a cylindrical shell and a conical shell, wherein the conical shell is arranged at one end of the cylindrical shell, and a ring laser and an optical camera are arranged on the conical shell to position the pipe inner wall weld; the cylindrical shell is connected to a right-angle fixed bracket, and the cylindrical shell is installed by the right-angle fixed bracket; the optical camera is installed on the conical shell by a camera support, and the camera support is adjusted by a C-shaped slide groove and a camera support positioning pin to adjust the pitch angle of the optical camera.

[0007] Furthermore, a camera protection shell is provided at the connection between the cylindrical shell and the conical shell, and an optical camera is provided in the camera protection shell.

[0008] Furthermore, a ring laser is installed at one end of the conical shell away from the cylindrical shell.

[0009] Furthermore, the ring laser emits a ring laser to form a ring laser mark on the inner wall of the pipeline to be inspected. After the optical cameras collect the laser marks in their respective fields of view, they perform image stitching.

[0010] Furthermore, a slide slot positioning screw is provided on the camera support, and a fastening nut is connected to the slide slot positioning screw. The slide slot positioning screw is slidably set in the C-shaped slide slot, and the fastening nut is manually tightened to fix the position of the camera support.

[0011] Furthermore, a camera support locating pin is provided in the middle of the camera support, and the camera support locating pin determines the movement center of the camera support.

[0012] Furthermore, the right-angle fixing bracket includes a first fixing plate and a second fixing plate, the first fixing plate is provided with a cable through hole, and two reinforcing ribs are welded between the first fixing plate and the second fixing plate.

[0013] Furthermore, a fixing screw is screwed on the first fixing plate, and the fixing screw is connected to the cylindrical shell. A threaded mounting hole is provided on the second fixing plate so as to be connected to the motion mechanism.

[0014] Furthermore, a plurality of internal frames are arranged at intervals inside the conical shell to fix and support the conical shell.

[0015] Furthermore, a plurality of camera protection shells are radially and spaced apart at the connection between the cylindrical shell and the conical shell.

[0016] The probe-type pipe inner wall weld positioning device of the present invention has the following advantages: After fixing the camera angle, the welds of pipes within a certain inner diameter range can be inspected. By connecting a C-shaped slide at the rear of the camera to adjust the pitch angle of the camera, the inspection range can be adjusted. This flexibility allows the device to be widely used in various inner diameter ranges of pipe weld inspection occasions. This application detects the linear fluctuations of the circular laser marking line on the inner wall of the pipe, and identifies the position of the weld on the inner wall of the pipe based on the frequency domain analysis method combined with a bandpass filter. Therefore, it has a strong anti-noise effect and is less affected by environmental interference, making this method have high sensitivity, detection efficiency and adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the probe-type pipe inner wall weld positioning device of the present invention; Figure 2 It is a schematic diagram of the internal structure of the probe-type pipe inner wall weld positioning device of the present invention; Figure 3 It is a front view of the probe-type pipe inner wall weld positioning device of the present invention; Figure 4 It is a side view of the C-shaped slideway of the probe-type pipe inner wall weld positioning device of the present invention; Figure 5 It is an isometric projection diagram of a C-shaped slideway of the probe-type pipe inner wall weld positioning device of the present invention; Figure 6 It is a schematic structural diagram of a right-angle fixing bracket of a probe-type pipe inner wall weld positioning device of the present invention; Figure 7 This is a schematic diagram of the coordinate distribution of the inner wall of the pipeline; Figure 8 It is the frequency spectrum of the normalized pipe inner wall coordinates; Fig. 9 It is the distribution diagram of the weld position detection signal after bandpass filtering; Fig.10 This is a schematic diagram of the software interface and weld position detection; Fig.11 This is a locally enlarged view of the weld location.

[0018] Description of the markings in the figure: 1. Cylindrical shell; 2. Conical shell; 3. Ring laser; 4. Camera protective shell; 5. Right-angle fixing bracket; 51. First fixing plate; 52. Second fixing plate; 6. Optical camera; 7. C-type slide groove; 8. Internal skeleton; 9. Threaded mounting hole; 10. Fastening nut; 11. Slide groove positioning screw; 12. Camera support; 13. Camera support positioning pin; 14. Fixing screw; 15. Cable through hole; 16. Reinforcement rib. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] Those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0021] Please refer to the attached Figure 1 To Attachment Fig.11 The invention discloses a probe-type pipe inner wall weld positioning device.

[0022] like Figures 1 to 3 As shown, the probe-type pipe inner wall weld positioning device of the present invention includes a cylindrical shell 1 and a conical shell 2, the conical shell 2 is arranged at one end of the cylindrical shell 1, and a ring laser 3 and an optical camera 6 are arranged on the conical shell 2 to position the inner wall weld of the pipeline; the cylindrical shell 1 is connected to the right-angle fixed bracket 5, and the cylindrical shell 1 is installed by the right-angle fixed bracket 5; the optical camera 6 is installed on the conical shell 2 by a camera support 12, and the camera support 12 is adjusted by a C-shaped slide groove 7 and a camera support positioning pin 13 to adjust the pitch angle of the optical camera 6.

[0023] After the camera angle is fixed, the weld seam of the pipe within a certain inner diameter range can be inspected. The C-shaped slide slot 7 is connected to the rear of the camera to adjust the pitch angle of the camera, and the inspection range can be adjusted. This flexibility allows the device to be widely used in various inner diameter ranges of pipe weld inspection occasions. The present application detects the linear fluctuation of the circular laser marking line on the inner wall of the pipe, and identifies the position of the weld seam on the inner wall of the pipe based on the frequency domain analysis method combined with a bandpass filter. Therefore, it has a strong anti-noise effect and is less affected by the environment, which makes the method have high sensitivity, detection efficiency and adaptability.

[0024] Further, if Figure 1 As shown, a camera protection shell 4 is provided at the connection between the cylindrical shell 1 and the conical shell 2, and an optical camera 6 is provided inside the camera protection shell 4; a ring laser 3 is installed at one end of the conical shell 2 away from the cylindrical shell 1; the ring laser 3 emits a ring laser to form a ring laser mark on the inner wall of the pipeline to be inspected, and the optical cameras 6 respectively collect the laser marks in their respective fields of view and then perform image stitching.

[0025] In this embodiment, preferably, the top of the cylindrical shell 1 is a conical shell 2, which is formed by integrated milling. Five camera protective shells 4 are installed at the connection between the cylindrical shell 1 and the conical shell 2, and are evenly distributed in the radial direction of the cylindrical shell 1. The shell provides protection for internal devices and cables from dust and collision.

[0026] The ring laser 3 is installed at the top of the conical shell 2, emitting a 650nm wavelength ring laser beam with a power of 200mW; the ring laser 3 emits a ring laser to form a ring laser mark on the inner wall of the pipeline to be detected. After the five optical cameras 6 respectively collect the laser marks in their respective fields of view, they perform image stitching to form complete ring mark coordinates in the software system, and then through polar coordinate transformation, Fourier transform, bandpass filtering, Fourier inverse transform, and setting appropriate thresholds, the weld position on the inner wall of the pipeline is finally obtained.

[0027] Further, if Figure 1 and Figure 4As shown, a slide groove positioning screw 11 is provided on the camera support 12, and a fastening nut 10 is connected to the slide groove positioning screw 11. The slide groove positioning screw 11 is slidably set in the C-shaped slide groove 7, and the fastening nut 10 is manually tightened to fix the position of the camera support 12; a camera support positioning pin 13 is provided in the middle of the camera support 12, and the camera support positioning pin 13 determines the movement center of the camera support 12.

[0028] In this embodiment, preferably, the C-shaped slide groove 7 is installed on both sides of the bottom of the camera support 12 and is symmetrically distributed. The pitch angle of the optical camera 6 is completed by the slide groove positioning screw 11 and the camera support positioning pin 13; the camera support positioning pin 13 determines the movement center of the camera support 12, and the C-shaped slide groove 7 determines the movement range of the camera support 12. Finally, the position of the camera support 12 is fixed by manually tightening the fastening nut 10 to complete the adjustment of the camera pitch angle.

[0029] Further, if Figure 5 and Figure 6 As shown, the right-angle fixed bracket 5 includes a first fixing plate 51 and a second fixing plate 52, the first fixing plate 51 is provided with a cable through hole 15, and two reinforcing ribs 16 are welded between the first fixing plate 51 and the second fixing plate 52; a fixing screw 14 is threaded on the first fixing plate 51, and the fixing screw 14 is connected to the cylindrical shell 1, and a threaded mounting hole 9 is provided on the second fixing plate 52 for connection with the moving mechanism; a plurality of internal skeletons 8 are arranged at intervals inside the conical shell 2 to fix and support the conical shell 2; a plurality of camera protective shells 4 are arranged radially and at intervals at the connection between the cylindrical shell 1 and the conical shell 2.

[0030] In this embodiment, preferably, the right-angle fixed bracket 5 is formed by vertically welding a first fixed plate 51 and a second fixed plate 52. The first fixed plate 51 is connected to the cylindrical shell 1 by a fixing screw 14. The first fixed plate 51 is provided with a cable through hole 15 to solve the wiring problem of the optical camera 6. The optical camera 6 adopts a 1200w pixel array camera, and the working distance range includes 300mm to 1500mm. The second fixed plate 52 is provided with a plurality of threaded mounting holes 9 to facilitate connection with other motion mechanisms.

[0031] Two reinforcing ribs 16 are welded in parallel and spaced apart between the first fixing plate 51 and the second fixing plate 52 to enhance the overall rigidity, and the two reinforcing ribs 16 are located on both sides of the cable through-hole 15; the internal skeleton 8 is five aluminum alloy special-shaped plates, which are cut from 3 mm thick aluminum alloy plates and play a role in fixing the outer shell and supporting the inner part of the conical outer shell 2.

[0032] The use process of the probe-type pipe inner wall weld positioning device of the present application is as follows: This embodiment requires that the detection pipe diameter range is 760mm-2650mm, the weld height is 1mm-3mm, and the weld width is about 5mm-10mm.

[0033] First, the pitch angle of the camera is calibrated according to the required detection range. The equipment is calibrated using cylindrical welded pipes with diameters of 760 mm and 2650 mm respectively. After the camera of the device penetrates at least 50 mm into the pipe mouth, the ring laser 3 is started. The operator manually adjusts the slot positioning screws 11 on the C-shaped slot 7 to adjust the pitch angle of the optical camera 6 so that the field of view of the five optical cameras 6 includes the inner wall area of ​​the detected pipeline, and can completely and clearly capture the laser marks on the inner wall of the pipeline within the diameter range of 760 mm to 2650 mm. After the angle is determined, tighten the fastening nut 10.

[0034] After completing the above calibration, perform weld inspection according to the following steps: 1. The device is driven by a robotic arm to probe into the pipe. After ensuring that the camera penetrates at least 50 mm into the pipe mouth, the ring laser 3 is started to emit laser. The plane formed by the laser beam is perpendicular to the axial direction of the pipe, thus forming a red laser ring perpendicular to the axial direction of the pipe on the inner wall of the pipe.

[0035] 2. The host computer splices the images collected by the five optical cameras 6 to obtain the integrated coordinate values ​​of the ring laser mark in polar coordinates with the ring laser 3 as the origin. Assume that this polar coordinate system is P:R,θ, then the coordinate value of the ring laser mark is (R(θ),θ), 0≤θ≤2π, and the horizontal position is θ=0, and R(θ) is the distance from the inner wall of the pipe to the origin of the polar coordinates when the angle is θ.

[0036] 3. Convert the point set {(R(θ),θ) | 0≤θ≤2π} according to (1) to obtain the mapping from the polar coordinate system P:R to the Cartesian coordinate system W:XOY , 0≤θ≤2π (1) The point set {θ, R(θ)} is converted into the point set {(x, y)} in the rectangular coordinate system. Since the data in formula (1) is discrete sampling, the point set {(x, y)} can be expressed as a sequence {y0, y1, ..., yN-1}, N = 2π / ∆θ, where ∆θ is the angular resolution of the camera for laser marking sampling, ∆θ>0.

[0037] 4. Use (2) to perform Fourier transform on {y0,y1,...,yN-1} (2) Set a suitable band-pass filter \(0 < b_{min}<b_{max}<1\) (where \(b_{min}\) and \(b_{max}\) are the lower and upper cut-off frequencies of the band-pass filter in the normalized frequency range, and these two frequencies are set according to the characteristics of the actual object). Use formula (3) to perform band-pass filtering on it so as to remove the low-frequency background signal and high-frequency noise, and obtain the weld signal in the frequency domain , where \(k\) is the frequency index.

[0038] (3) 5. Use formula (4) to perform inverse Fourier transform to obtain the coordinates of the weld in the Cartesian coordinate system \(W:XOY\) , where \(n = 0,1,\cdots,N - 1\), (4) The point set \(\{( , )\}\) is the signal of the inner wall of the pipeline after band-pass filtering, which can be expressed in the polar coordinate system \(P:R,\theta\), , \(0\leq \leq2\pi\), \(n = 0,1,\cdots,N - 1\) (5) For the radius sequence \({ \}\) obtained from formula (5), find the serial number \(n\) corresponding to the maximum value of \({ \) max , \(n = 0,1,\cdots,N - 1\) (6) Then is the position corresponding to the detected weld, and the angle of the weld in polar coordinates is .

[0039] Example 1. For a welded pipe with an inner diameter of 1628 mm, the weld height is about 2 mm, and the weld width is about 8.1 mm. The test process and results of the present invention are as follows: The host controls the camera to sample and splice the annular laser line. After polar coordinate conversion corresponding to formula (1), the inner wall coordinate diagram of the pipeline in polar coordinates as shown in Figure 7 is obtained, and the sequence is denoted as \(\{y_0,y_1,\cdots,y_{N - 1}\}\), \(N = 10000\). Perform Fourier transform using formula (2) to obtain the frequency spectrum as shown in Figure 8 .

[0040] Apply the band-pass filtering described in formula (3) to the Figure 8 shown frequency spectrum. The upper and lower cut-off frequencies are taken as \(b_{min}=0.25\) and \(b_{max}=0.95\) respectively. Then, according to formula (4), the signal distribution after inverse Fourier transform is obtained as shown in Fig. 9 Formula (5) maps the signal in the plane coordinates of formula (4) to the polar coordinates. The signal sequence { } is processed as in formula (6) to obtain the sequence { }The subscript of the maximum value in =4392, which corresponds to the position of the detected weld =158.1°, Fig.10 This is the software interface and the schematic diagram of the weld detection. The green circle in the figure is the inner wall of the pipe, and the blue straight line indicates that the weld being detected is located at 158.1°. Fig.11 The above results prove the effectiveness of the present invention in the application example.

[0041] The probe-based pipe inner wall weld positioning device can detect welds of pipes within a certain inner diameter range by fixing the camera angle. The C-shaped slide 7 is connected to the rear of the camera to adjust the camera's pitch angle, and the detection range can be adjusted. This flexibility allows the device to be widely used in pipe weld detection occasions with a variety of inner diameter ranges. This application detects the linear fluctuations of the annular laser marking line on the inner wall of the pipe, and identifies the position of the weld on the inner wall of the pipe based on the frequency domain analysis method combined with a bandpass filter. Therefore, it has a strong anti-noise effect and is less affected by environmental interference, making the method have high sensitivity, detection efficiency and adaptability.

[0042] By connecting the right-angle fixed bracket 5 with the motion mechanism, the position of the ring laser 3 can be adjusted, so that the mechanism can penetrate into the interior of the pipeline for detection, which has a high degree of automation and enhances work efficiency and convenience of operation; the conical housing 2 provides physical protection for the internal ring laser 3, camera and other sensitive components, extending the service life of the equipment. The protective shell outside the camera further ensures the safety of the camera working in various environments, enhancing the durability and reliability of the equipment.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A probe-type pipe inner wall weld positioning device, characterized in that: It includes a cylindrical shell and a conical shell. The conical shell is arranged at one end of the cylindrical shell. A ring laser and an optical camera are arranged on the conical shell to locate the weld on the inner wall of the pipeline. The cylindrical shell is connected to a right-angle fixed bracket, and the cylindrical shell is installed through the right-angle fixed bracket. The optical camera is installed on the conical shell by a camera support, and the camera support is adjusted by a C-shaped slide groove and a camera support positioning pin to adjust the pitch angle of the optical camera.

2. The probe-type pipe inner wall weld positioning device according to claim 1 is characterized in that: A camera protection shell is arranged at the connection between the cylindrical shell and the conical shell, and an optical camera is arranged in the camera protection shell.

3. The probe-type pipe inner wall weld positioning device according to claim 2 is characterized in that: A ring laser is installed at one end of the conical shell away from the cylindrical shell.

4. The probe-type pipe inner wall weld positioning device according to claim 3 is characterized in that: The ring laser emits a ring laser to form a ring laser mark on the inner wall of the pipeline to be inspected. After the optical cameras collect the laser marks in their respective fields of view, they perform image stitching.

5. The probe-type pipe inner wall weld positioning device according to claim 1, characterized in that: The camera support is provided with a slide groove positioning screw, and the slide groove positioning screw is connected with a fastening nut. The slide groove positioning screw is slidably set in the C-shaped slide groove, and the fastening nut is manually tightened to fix the position of the camera support.

6. The probe-type pipe inner wall weld positioning device according to claim 5, characterized in that: A camera support locating pin is arranged in the middle of the camera support, and the camera support locating pin determines the movement center of the camera support.

7. The probe-type pipe inner wall weld positioning device according to claim 1, characterized in that: The right-angle fixing bracket includes a first fixing plate and a second fixing plate. The first fixing plate is provided with a cable through hole. Two reinforcing ribs are welded between the first fixing plate and the second fixing plate.

8. The probe-type pipe inner wall weld positioning device according to claim 7, characterized in that: A fixing screw is screwed on the first fixing plate, and the fixing screw is connected to the cylindrical shell. A threaded mounting hole is provided on the second fixing plate so as to be connected to the motion mechanism.

9. The probe-type pipe inner wall weld positioning device according to claim 3, characterized in that: A plurality of internal frames are arranged at intervals inside the conical shell to fix and support the conical shell.

10. The probe-type pipe inner wall weld positioning device according to claim 2, characterized in that: A plurality of camera protection shells are arranged radially and at intervals at the connection between the cylindrical shell and the conical shell.

Images