A real-time visualization method and device for ultrasonic detection of weld defects

Abstract

The present invention discloses a real-time visualization method and device for ultrasonic detection of weld defects, which relates to the technical field of nondestructive detection of metal weld defects, and includes the following specific steps: Step 1: Use the device to scan the weld (such as the weld of an in-service pressure vessel), obtain the ultrasonic data of the weld and the inertial sensor data reflecting the plane position of the defect, and determine the defect category; Step 2: Analyze the ultrasonic data and the inertial sensor data, determine the spatial coordinates of the weld defect, and realize the spatial positioning and visualization of the defect; Step 3: Simulate and verify the ultrasonic detection process of the defective weld. This method, through ultrasonic and inertial sensor data, completes the visualization of ultrasonic propagation in the detection process and the volume visualization of weld defects, establishes a visualization database, realizes information traceability, and uses the data for dynamic safety evaluation of equipment. It can not only evaluate the safety of the equipment during regular inspection, but also provide data and model support for dynamic monitoring and evaluation of the equipment during in-service use.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive detection of metal weld defects, and in particular to a real-time visualization method and device for ultrasonic detection of weld defects. Background Art

[0002] Equipment is an important symbol of modern civilized society and an important foundation for social development. Without equipment, human beings will return to the ancient agricultural and pastoral era of manual labor. Welding is the basic process of almost all equipment manufacturing processes. Equipment involving major safety, such as boilers, pressure vessels, pressure pipes, elevators, lifting machinery, amusement facilities, motor vehicles, etc., have been included in the special equipment management by the state, and welds are the key parts that determine the safety and reliability of welding equipment or structures. For this reason, the Special Equipment Safety Management Regulations and relevant national standards not only require non-destructive testing of welds after equipment manufacturing is completed, but also require regular non-destructive testing and evaluation of welds of in-service equipment or structures. The number of special equipment in the petroleum and chemical industries is huge, and the regular inspection tasks are heavy. Production needs to be stopped during the regular inspection period. A large number of professionals and instruments are invested, the labor intensity is high, and the inspection cycle is long.

[0003] Ultrasonic testing technology has always been the main means of non-destructive testing of welds due to its advantages of low cost, high accuracy, environmental friendliness and portability. However, traditional ultrasonic testing has problems such as high requirements on the quality of testing personnel, long weld evaluation report cycle, poor traceability of testing data and inability to review. Visualizing ultrasonic information during weld testing can improve the evaluation efficiency of the testing process, reduce the requirements for testing personnel, improve data traceability and shorten the reporting cycle.

[0004] At present, in the literature research on ultrasonic testing of welds, "Analysis of Nondestructive Testing Methods for Finished Oil Pipelines", relevant comparative analysis shows that ultrasonic testing has advantages over phased array ultrasonic testing in terms of detection calibration, adjustment, technical requirements, etc. At the same time, most phased array devices have complex structures, such as: "Pressure Vessel Defect Detection Device" (CN201720851191.1) realizes the purpose of automatic detection of girth welds through the circumferential movement of the stepper motor on the gear groove; "A Weld Flaw Detection Device and Use Method for Pressure Vessels" (CN202211174021.6) designs a set of large-scale ultrasonic sliding ultrasonic detection devices based on ultrasonic waves, and transports the pressure vessel into the device to complete the detection and mark the defective parts; "A Through-Part Girth Weld Automatic Ultrasonic Detection Device" (CN202211103419. 0) It adopts a segmented splicing structure, which contains a laser paint removal module inside to automatically complete the defect detection of the weld; "An ultrasonic automatic detection device for ring welds" (CN202222485787.8) uses a tram to automatically complete the defect detection of the weld, ensuring the accuracy of the movement trajectory of the car and the relevant information of the defect; "An ultrasonic detection device for ring welds" (CN202320130479.5) designs a mobile ultrasonic ring weld detection box, which can complete the detection of the weld through the cylinder and translation structure, and is equipped with a vacuum cleaner to clean the detection surface. However, the existing technology still has the following limitations:

[0005] (1) There is a lack of real-time visualization of the ultrasonic propagation process, and high requirements for the judgment of defects and their evaluation reliability;

[0006] (2) It is impossible to form a visual database of ultrasonic detection of weld defects and their location, which is not convenient for achieving traceability and cannot provide support for dynamic monitoring of weld safety of production process equipment.

[0007] In order to solve the above problems, the present invention uses theoretical and experimental methods combined with the principle of ultrasonic detection to design a real-time visualization method and device for ultrasonic detection of weld defects. The overall structure of the device is simple and the cost is low. It can not only realize the visualization of ultrasonic propagation and defects, but also establish a complete weld database with defect locations, laying the foundation for in-service dynamic monitoring and real-time analysis of related equipment. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a real-time visualization method and device for ultrasonic detection of weld defects, which solves the problems raised in the above-mentioned background technology.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions: a real-time visualization method and device for ultrasonic detection of weld defects, comprising the following specific steps:

[0010] Step 1: Use the device to scan the weld, obtain the ultrasonic data of the weld and the inertial sensor data reflecting the plane position of the defect, and use the spectrum analysis of the ultrasonic data to determine the type of weld defect;

[0011] Step 2: Analyze the ultrasonic data and inertial sensor data to determine the spatial coordinates of the weld defects and realize the spatial positioning and visualization of the defects;

[0012] Step 3: Simulate and verify the ultrasonic detection process of defective welds.

[0013] Optionally, the specific method flow for judging the weld defect category is as follows:

[0014] (1) A transformer module is provided on the single chip microcomputer, which converts the 220V voltage into a 24V voltage to power the oblique ultrasonic transducer, so that it emits a cyclic pulse signal at a time interval and cyclically reads the ultrasonic echo signal;

[0015] (2) Using FPGA (field programmable gate array, FPGA is composed of a number of logic gate arrays) to collect the echo signal of the microcontroller at high speed. The specific collection process is as follows:

[0016] A. Select the parameters of the angle probe, including K value and frequency, based on industry standards and the wall thickness of the weld structure;

[0017] B. Apply coupling agent to the surface near the weld to be inspected, and use an angled probe with an arc, keeping the two in close contact;

[0018] C. The oblique probe emits ultrasonic waves, and receives echoes of cyclic pulse signals according to the ultrasonic propagation characteristics;

[0019] D. To analyze the ultrasonic echo signal, the signal needs to be processed for noise reduction to improve the signal-to-noise ratio;

[0020] It adopts self-programming and imports data into Unity3D, and completes the real-time display of waveforms through serial communication;

[0021] (3) The discrete defect ultrasonic amplitude signal is subjected to fast Fourier transformation to obtain the spectrum of various defect signals. It is found that the extreme frequencies of the three defects of crack, pore and slag inclusion are different, among which the transformation amplitude of crack is the largest and the transformation amplitude of slag inclusion is the smallest.

[0022] (4) Determine the defect type based on the main frequency.

[0023] Optionally, the single chip microcomputer is provided with two-stage bandpass filtering.

[0024] Optionally, a specific method flow for locating the defect spatial coordinates is as follows:

[0025] (1) By binding the oblique probe to the inertial sensor, before solving the probe attitude, the raw data output by each sensor in the IMU (Inertial measurement unit, a device used to measure the three-axis attitude angle and acceleration of an object, including a gyroscope and an accelerometer) needs to be corrected;

[0026] The calibration method of the accelerometer adopts the vertical hanging method, with the positive hanging and the reverse hanging lasting for 3 minutes each;

[0027] The calibration of the gyroscope uses the static denoising method to obtain the zero bias error of the three axes after static denoising, which is then eliminated in the subsequent process;

[0028] (2) The inertial sensor uploads the attitude data to the host computer through Bluetooth communication, imports it into the quaternion attitude interface of Unity3D, and translates it into double-precision floating-point numbers in real time to complete the attitude synchronization of the virtual probe; and uses the pre-integration algorithm to perform a second integration on the high-frequency IMU acceleration data to obtain the spatial displacement and fit it with the simulation animation function of Unity3D, so that the moving position of the probe is continuously updated with the acceleration data;

[0029] (3) Establish a corresponding database between the three-dimensional coordinates of the probe and the ultrasonic amplitude curve. In the host computer software, click on the acquisition coordinate point to view the amplitude curve of the point;

[0030] (4) Combining the characteristic signal of the defect with the propagation characteristics of the ultrasonic wave, the incident angle and the wall thickness, the three-dimensional coordinates of the defect can be calculated.

[0031] Optionally, the process of simulating and verifying the ultrasonic detection process of defective welds is as follows:

[0032] (1) A weld model is pre-built using COMSOL software, and the following parameters are converted into variables, including the height of the weld structure, the diameter of the cylinder, and the wall thickness;

[0033] (2) Input the parameters in the form of an input box through the software prefabricated App, thus completing the parametric modeling of the overall three-dimensional model of the pressure vessel;

[0034] (3) According to the industry standard NBT47013.3-2015, the specifications of the angle probe are selected based on the wall thickness of the pressure vessel, and the range of ultrasonic testing required is dynamically rendered by combining the K value of the angle probe with the wall thickness of the pressure vessel;

[0035] (4) Combining the piezoelectric-acoustic physical field simulation of COMSOL and the three-dimensional spatial coordinates of the probe and the defect, the axial cross-section of the pressure vessel is parameterized and the amplitude curve is simulated. The curve is then compared with the actual amplitude curve for verification and analysis.

[0036] A real-time visualization device for ultrasonic detection of weld defects comprises a computer with a multifunctional software system for data acquisition, data processing, data analysis, defect visualization and ultrasonic detection process simulation.

[0037] Optionally, the computer is interactively connected to the FPGA sampling board, the FPGA sampling board is interactively connected to the single-chip microcomputer, the single-chip microcomputer is interactively connected to the detection vehicle, encoding motors are respectively provided at the front and rear of the bottom end of the detection vehicle, a rotating hinge is provided on the outside of the encoding motor, a large magnetic wheel is provided on the side of the rotating hinge away from the encoding motor, auxiliary rail slots are provided on both sides of the detection vehicle, a metal film track slot is horizontally penetrated inside the auxiliary rail slot, small magnetic wheels are provided at both ends of the metal film track slot, an inertial sensor is provided in the middle of the top end of the detection vehicle, coupling agent spray devices are provided on both sides of the inertial sensor, and magnetic pressure spring supports connected to the detection vehicle are provided on both sides of the outside of the coupling agent spray device.

[0038] Optionally, the single chip microcomputer has an ultrasonic excitation, and the single chip microcomputer also includes a 220V to 24V transformer and an ultrasonic echo signal sampling point.

[0039] Optionally, the auxiliary rail slots are symmetrically distributed about a center line of the inspection vehicle.

[0040] Optionally, the magnetic pressure spring support and the coupling agent spraying device are symmetrically distributed about the center line of the inertial sensor.

[0041] The present invention provides a real-time visualization method and device for ultrasonic detection of weld defects, which has the following features:

[0042] Beneficial effects:

[0043] The real-time visualization method and device for ultrasonic detection of weld defects solves the visualization of the ultrasonic non-destructive detection process, reduces the requirements for detection personnel, and improves the reliability and speed of defects and their evaluation; improves the detection efficiency, including improving the detection efficiency and the efficiency of forming evaluation reports, shortening the detection cycle, and reducing the impact cycle on production; the formed visualization database of ultrasonic detection of weld defects and their positioning provides basic support for the traceability of weld safety evaluation and the dynamic monitoring of equipment weld safety, which is conducive to further improving production safety; the device has a simple structure, good portability, low cost, and can also identify the type of weld defects;

[0044] The design improves the traditional A-type ultrasonic pulse reflection defect detection method. While retaining the characteristics of A-type ultrasound (economical, portable, simple structure, and accurate positioning), it can effectively avoid missed detection and misjudgment of artificial defects; combined with the requirements of industry standard NBT47013.3-2015 and the inertial data of the probe, the detection range is visualized; while improving the detection efficiency, it can provide a new online monitoring method for in-service pressure vessels; it solves the visualization of the ultrasonic non-destructive testing process, reduces the requirements for inspection personnel, and improves the reliability of defects and their evaluation; establishes a visual database for ultrasonic detection of weld defects and their positioning, which provides basic support for the traceability of weld safety evaluation and the dynamic monitoring of equipment weld safety, which is conducive to further improving production safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the detection principle flow in the first embodiment of the invention;

[0046] Figure 2 It is a flow chart of a method for distinguishing different defect types of an in-service pressure vessel in the first embodiment of the invention;

[0047] Figure 3 It is a schematic flow chart of a method for locating the spatial coordinates of defects in an in-service pressure vessel in the first embodiment of the invention;

[0048] Figure 4 It is a schematic diagram of simulation animation function fitting in the first embodiment of the invention;

[0049] Figure 5 It is a schematic diagram of the axial cross-sectional structure of the pressure vessel in the first embodiment of the invention;

[0050] Figure 6 It is a flow chart of the defect ultrasonic simulation verification method in the first embodiment of the invention;

[0051] Figure 7 It is a simulation schematic diagram of the amplitude curve in the first embodiment of the invention;

[0052] Figure 8 This is a schematic diagram of the main structure in the second embodiment of the invention;

[0053] Fig. 9 It is a schematic diagram of the top view structure in the second embodiment of the invention;

[0054] Fig.10 It is a schematic diagram of the ultrasonic amplitude curve of a crack in the second embodiment of the invention;

[0055] Fig.11 It is a schematic diagram of the pore ultrasonic amplitude curve in the second embodiment of the invention;

[0056] Fig.12It is a schematic diagram of the slag inclusion ultrasonic amplitude curve in the second embodiment of the invention.

[0057] In the figure: 1. Computer; 2. FPGA sampling board; 3. Single chip microcomputer; 301. 220V to 24V transformer; 302. Ultrasonic echo signal sampling point; 4. Small magnetic wheel; 5. Metal film track groove; 6. Magnetic pressure spring support; 7. Coupling agent spray device; 8. Inertial sensor; 9. Encoder motor; 10. Rotary hinge; 11. Auxiliary rail slot; 12. Large magnetic wheel; 13. Inspection vehicle; 14. Oblique probe slot. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0059] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and 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 operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0060] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] Example 1: Please refer to Figures 1 to 7 , a real-time visualization method for ultrasonic detection of weld defects, comprising the following specific steps:

[0062] Step 1: Identify different defect types of pressure vessels in service;

[0063] The specific method and process for distinguishing different defect types of in-service pressure vessels are as follows:

[0064] (1) The single chip computer 3 is provided with a voltage conversion module, which converts the 220V voltage into a 24V voltage to power the oblique ultrasonic transducer, so that it emits a cyclic pulse signal within a time interval and cyclically reads the ultrasonic echo signal. The single chip computer 3 is provided with a two-stage bandpass filter;

[0065] (2) using FPGA to collect echo signals of single-chip computer 3 at high speed;

[0066] A. Select the parameters of the angle probe, including K value and frequency, based on the industry standard and the wall thickness of the pressure vessel;

[0067] B. Apply coupling agent on the surface of the pressure vessel to be tested and use an angled probe with a curvature, keeping the two in close contact;

[0068] C. The oblique probe emits ultrasonic waves, and receives echoes of cyclic pulse signals according to the ultrasonic propagation characteristics;

[0069] D. To analyze the ultrasonic echo signal, the signal needs to be processed for noise reduction to improve the signal-to-noise ratio;

[0070] The program was programmed in MATLAB and imported into Unity3D, and the real-time display of the waveform was completed through serial communication.

[0071] (3) The discrete defect ultrasonic amplitude signal is subjected to fast Fourier transformation to obtain the spectrum of various defect signals. It is found that the extreme frequencies of the three defects of crack, pore and slag inclusion are different, among which the transformation amplitude of crack is the largest and the transformation amplitude of slag inclusion is the smallest.

[0072] (4) The defect type can be determined based on the main frequency;

[0073] Step 2: Locate the spatial coordinates of defects in the pressure vessel in service;

[0074] The specific method and process for locating the spatial coordinates of defects in in-service pressure vessels are as follows:

[0075] (1) By binding the oblique probe to the inertial sensor 8, the raw data output by each sensor in the IMU needs to be corrected before solving the probe attitude;

[0076] The calibration method of the accelerometer adopts the vertical hanging method, with the positive hanging and the reverse hanging lasting for 3 minutes each;

[0077] The calibration of the gyroscope uses the static denoising method to obtain the zero bias error of the three axes after static denoising, which is then eliminated in the subsequent process;

[0078] (2) The inertial sensor 8 uploads the attitude data to the host computer through Bluetooth communication, imports it into the quaternion attitude interface of Unity3D, and translates it into double-precision floating-point numbers in real time to complete the attitude synchronization of the virtual probe; and uses the pre-integration algorithm to perform secondary integration on the high-frequency IMU acceleration data to obtain the spatial displacement and fit it with the simulation animation function of Unity3D, so that the moving position of the probe is continuously updated with the acceleration data;

[0079] (3) Establish a corresponding database between the three-dimensional coordinates of the probe and the ultrasonic amplitude curve. In the host computer software, click on the acquisition coordinate point to view the amplitude curve of the point;

[0080] (4) Combining the characteristic signal of the defect with the propagation characteristics of the ultrasonic wave, the incident angle and the wall thickness, the three-dimensional coordinates of the defect can be calculated;

[0081] Step 3: Ultrasonic simulation verification of defects;

[0082] The process of simulation verification of ultrasonic testing of welds with defects is as follows:

[0083] (1) Pre-build a pressure vessel using COMSOL software and change the following parameters into variables, including the head height, cylinder diameter, and wall thickness;

[0084] (2) Input the parameters in the form of an input box through the software prefabricated App, thus completing the parametric modeling of the overall three-dimensional model of the pressure vessel;

[0085] (3) According to the industry standard NBT47013.3-2015, the specifications of the angle probe are selected based on the wall thickness of the pressure vessel, and the range of ultrasonic testing required is dynamically rendered by combining the K value of the angle probe with the wall thickness of the pressure vessel;

[0086] (4) Combining the piezoelectric-acoustic physical field simulation of COMSOL and the three-dimensional spatial coordinates of the probe and the defect, the axial cross-section of the pressure vessel is parameterized and the amplitude curve is simulated. The curve is then compared with the actual amplitude curve for verification and analysis.

[0087] Example 2: Please refer to Figures 8 to 9A real-time visualization device for ultrasonic detection of weld defects includes a computer 1, wherein the computer 1 is interactively connected to an FPGA sampling board 2, the FPGA sampling board 2 is interactively connected to a single-chip microcomputer 3, and the single-chip microcomputer 3 is interactively connected to a detection vehicle 13. Encoding motors 9 are respectively arranged at the front and rear of the bottom of the detection vehicle 13, a rotating hinge 10 is arranged on the outer side of the encoding motor 9, and a large magnetic wheel 12 is arranged on the side of the rotating hinge 10 away from the encoding motor 9. Auxiliary rail slots 11 are arranged on both sides of the detection vehicle 13, and a metal film track slot 5 is horizontally penetrated inside the auxiliary rail slot 11, and small magnetic wheels 4 are arranged at both ends of the metal film track slot 5. An inertial sensor 8 is arranged in the middle of the top of the detection vehicle 13, and coupling agent spraying devices 7 are arranged on both sides of the inertial sensor 8. Magnetic pressure spring pillars 6 connected to the detection vehicle 13 are arranged on both sides of the outer side of the coupling agent spraying device 7.

[0088] In this embodiment, the single chip microcomputer 3 has an ultrasonic excitation device, and the single chip microcomputer 3 also includes a 220V to 24V transformer 301 and an ultrasonic echo signal sampling point 302 .

[0089] In this embodiment, the auxiliary rail slots 11 are symmetrically distributed about the center line of the inspection vehicle 13 .

[0090] In this embodiment, the magnetic pressure spring support 6 and the coupling agent spraying device 7 are symmetrically distributed about the center line of the inertial sensor 8 .

[0091] like Figures 1 to 12As shown, firstly, the accelerometer and gyroscope of the inertial sensor 8 are calibrated, and the carrier coordinate system is reset; in combination with the specific parameters (wall thickness) of the detection object, the appropriate oblique probe parameters (K value, frequency) are selected, and the selected oblique probe is embedded in the oblique probe slot 14 of the detection vehicle 13; according to the industry standard NBT47013.3-2015, the detection range of the weld is determined, the small magnetic wheel 4 and the large magnetic wheel 12 are fitted with the pressure vessel to be tested, and the coupling agent spray device 7 is filled; the coupling agent spray device 7 is turned on, and the ultrasonic excitation is started. After the waveform signal of this point is transmitted to the computer 1, the encoding motor 9 is started to slowly move the detection vehicle 13 from the left end to the right end of the metal film track groove 5. Each time the detection vehicle 13 moves, an ultrasonic excitation signal is emitted, and the ultrasonic waveform data is collected at high speed by the FPGA sampling board 2. When the detection vehicle 13 moves to the right end, the metal film track groove 5 is Move along the circumferential direction of the pressure vessel, and complete the front laying of the track while the inspection vehicle 13 is stationary, so that the inspection vehicle 13 is again at the left end of the metal film track groove 5, and repeat this operation until the entire circumferential detection is completed; after the circumferential detection is completed, the inspection vehicle 13 is lifted by pressing the magnetic pressure spring support 6 on the top of the inspection vehicle 13, and the four large magnetic wheels 12 of the inspection vehicle 13 are rotated by the rotating hinge 10 to rotate to the axial direction parallel to the pressure vessel, and the magnetic pressure spring support 6 is pressed again to make the large magnetic wheels 12 fit the pressure vessel and complete the axial displacement. The displacement size is recorded by the encoder motor 9 and controlled by the computer 1, and the above-mentioned circumferential detection method is repeated until the non-destructive detection of the entire circumferential weld to be inspected is completed; (Note: The pressure vessel mainly has circumferential welds and longitudinal welds. Since the metal film track groove 5 is made of a relatively soft material, it can also be paved to complete the detection of the longitudinal weld);

[0092] Then, the inertial data of the probe and the movement data of the encoder motor 9 are obtained through the inertial sensor 8, and the discrete ultrasonic three-dimensional sampling points on the pressure vessel are matched one by one with the discrete ultrasonic amplitude curves in the computer 1. Taking pores, slag and cracks as examples, the ultrasonic amplitude curves are as follows: Figures 10 to 12 As shown:

[0093] The discrete amplitude curve can be transformed into a short-time Fourier transform through the algorithm of computer 1 to distinguish the main frequencies of the three defects, thereby realizing the recognition of characteristic signals and the determination of defects; the spatial position of the defect can be calculated by combining the known spatial position of the sampling point of the defect with the probe parameters (K value); the spatial position of the defect is parameterized by COMSOL software (narrow rectangles are used for cracks and circles are used for pores and slag inclusions) to complete the two-dimensional cross-sectional modeling of the sampling point, and piezoelectric acoustic ultrasonic simulation is performed by COMSOL software, and the simulation results are discretely compared with the actually measured ultrasonic amplitude curve, which can assist in determining whether the defect exists and avoid missed detection and false detection.

[0094] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A real-time visualization method for ultrasonic detection of weld defects, characterized in that: The specific steps include: Step 1: Use the device to scan the weld, obtain the ultrasonic data of the weld and the inertial sensor data reflecting the plane position of the defect, and use the spectrum analysis of the ultrasonic data to determine the type of weld defect. The specific method flow is as follows: (1) A transformer module is provided on the single chip computer (3), which converts the 220V voltage into a 24V voltage to power the oblique ultrasonic transducer, so that it emits a cyclic pulse signal within a time interval and cyclically reads the ultrasonic echo signal; (2) Using FPGA to collect the echo signal of the single chip computer (3) at high speed, the specific collection process is as follows: A. Select the parameters of the angle probe, including K value and frequency, based on industry standards and the wall thickness of the weld structure; B. Apply coupling agent to the surface near the weld to be inspected, and use an angled probe with an arc, keeping the two in close contact; C. The oblique probe emits ultrasonic waves, and receives echoes of cyclic pulse signals according to the ultrasonic propagation characteristics; D. To analyze the ultrasonic echo signal, the signal needs to be processed for noise reduction to improve the signal-to-noise ratio; It adopts self-programming and imports data into Unity3D, and completes the real-time display of waveforms through serial communication; (3) The discrete defect ultrasonic amplitude signal is subjected to fast Fourier transformation to obtain the spectrum of various defect signals. It is found that the extreme frequencies of the three defects of crack, pore and slag inclusion are different, among which the transformation amplitude of crack is the largest and the transformation amplitude of slag inclusion is the smallest. (4) Determine the defect type based on the main frequency; Step 2: Analyze the ultrasonic data and inertial sensor data to determine the spatial coordinates of the weld defects and realize the spatial positioning and visualization of the defects. The specific method flow is as follows: (1) By binding the oblique probe to the inertial sensor (8), the raw data output by each sensor in the IMU needs to be corrected before solving the probe attitude; The calibration method of the accelerometer adopts the vertical hanging method, with the positive hanging and the reverse hanging lasting for 3 minutes each; The calibration of the gyroscope uses the static denoising method to obtain the zero bias error of the three axes after static denoising, which is then eliminated in the subsequent process; (2) The inertial sensor (8) uploads the attitude data to the host computer via Bluetooth communication, imports it into the quaternion attitude interface of Unity3D, and translates it into double-precision floating-point numbers in real time to complete the attitude synchronization of the virtual probe; and uses the pre-integration algorithm to perform a second integration on the high-frequency IMU acceleration data to obtain the spatial displacement and fit it with the simulation animation function of Unity3D, so that the movement position of the probe is continuously updated with the acceleration data; (3) Establish a corresponding database between the three-dimensional coordinates of the probe and the ultrasonic amplitude curve. In the host computer software, click on the acquisition coordinate point to view the amplitude curve of the point; (4) Combining the characteristic signal of the defect with the propagation characteristics of the ultrasonic wave, the incident angle and the wall thickness, the three-dimensional coordinates of the defect can be calculated; Step 3: Simulate and verify the ultrasonic testing process of defective welds. The process is as follows: (1) A weld model is pre-built using COMSOL software, and the following parameters are converted into variables, including the height of the weld structure, the diameter of the cylinder, and the wall thickness; (2) Input the parameters in the form of an input box through the software prefabricated App, thus completing the parametric modeling of the overall three-dimensional model of the pressure vessel; (3) According to the industry standard NBT47013.3-2015, the specifications of the angle probe are selected based on the wall thickness of the pressure vessel, and the range of ultrasonic testing required is dynamically rendered by combining the K value of the angle probe with the wall thickness of the pressure vessel; (4) Combining the piezoelectric-acoustic physical field simulation of COMSOL and the three-dimensional spatial coordinates of the probe and the defect, the axial cross-section of the pressure vessel is parameterized and the amplitude curve is simulated. The curve is then compared with the actual amplitude curve for verification and analysis.

2. A real-time visualization method for ultrasonic detection of weld defects according to claim 1, characterized in that: The single chip computer (3) is provided with two-stage bandpass filtering.

3. A real-time visualization device for ultrasonic detection of weld defects as described in any one of claims 1 to 2, comprising a computer (1) having a multifunctional software system for data acquisition, data processing, data analysis, defect visualization, and ultrasonic detection process simulation.

4. A real-time visualization device for ultrasonic detection of weld defects according to claim 3, characterized in that: The computer (1) is interactively connected to the FPGA sampling board (2), the FPGA sampling board (2) is interactively connected to the single-chip computer (3), and the single-chip computer (3) is interactively connected to the detection vehicle (13). The bottom of the detection vehicle (13) is provided with an encoding motor (9) at the front and rear ends, respectively. A rotating hinge (10) is provided on the outer side of the encoding motor (9). A large magnetic wheel (12) is provided on the side of the rotating hinge (10) away from the encoding motor (9). Auxiliary rail slots (12) are provided on both sides of the detection vehicle (13). 1), a metal film track groove (5) is horizontally penetrated inside the auxiliary track groove (11), small magnetic wheels (4) are arranged at both ends of the metal film track groove (5), an inertial sensor (8) is arranged at the middle of the top of the detection vehicle (13), coupling agent spraying devices (7) are arranged on both sides of the inertial sensor (8), magnetic pressure spring pillars (6) connected to the detection vehicle (13) are arranged on both sides of the outside of the coupling agent spraying device (7), and an oblique probe groove (14) is arranged at the middle of the bottom of the detection vehicle (13).

5. A real-time visualization device for ultrasonic detection of weld defects according to claim 4, characterized in that: The single chip microcomputer (3) has an ultrasonic excitation device inside, and the single chip microcomputer (3) also includes a 220V to 24V transformer (301) and an ultrasonic echo signal sampling point (302).

6. A real-time visualization device for ultrasonic detection of weld defects according to claim 4, characterized in that: The auxiliary rail slots (11) are symmetrically distributed about the center line of the inspection vehicle (13).

7. The real-time visualization device for ultrasonic detection of weld defects according to claim 4, characterized in that: The magnetic pressure spring support (6) and the coupling agent spraying device (7) are symmetrically distributed about the center line of the inertial sensor (8).

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