A composite sensor and detection method for pipeline non-destructive testing

Abstract

The application provides a composite sensor and a detection method for pipeline nondestructive testing, relates to the technical field of pipeline nondestructive testing, and comprises a magnetic base of a cylindrical structure; the magnetic base comprises a circular ring part and a center part; an electromagnetic ultrasonic coil; the electromagnetic ultrasonic coil comprises a first coil and a second coil which are interlaced and wound; a plurality of Hall elements are uniformly arranged in the circumferential direction with the center part as the center; and a controller is configured to generate a first control signal based on a magnetic flux leakage signal, to form a target excitation circuit based on the electromagnetic ultrasonic coil, to make the target excitation circuit form electromagnetic ultrasonic waves for detecting a pipeline to be detected, to obtain an ultrasonic echo based on the target excitation circuit, and to generate a detection result according to the magnetic flux leakage signal and the ultrasonic echo. The application realizes omnidirectional magnetic flux leakage detection through the annular magnet structure matched with the circumferentially arranged Hall elements; and through the specific combination of the coil connection mode and the timing control logic, various electromagnetic ultrasonic detection modes can be considered.

Description

Technical Field

[0001] This application relates to the field of pipeline nondestructive testing technology, and in particular to a composite sensor and testing method for pipeline nondestructive testing. Background Technology

[0002] Due to long-term exposure to factors such as media corrosion, pressure fluctuations, and environmental corrosion, pipelines are prone to various defects such as surface cracks, internal porosity / inclusions, and wall thinning. In order to detect defects in a timely manner and take remedial measures, it is necessary to conduct non-destructive testing on pipelines regularly.

[0003] Currently, commonly used technologies for non-destructive testing of pipelines include magnetic flux leakage (MFL) and electromagnetic ultrasonic testing. MFL is based on the principle of magnetic flux leakage at defects in magnetized ferromagnetic materials, identifying defects by detecting changes in the leakage magnetic field. It features high detection speed, but its sensitivity to deep defects is relatively low. Electromagnetic ultrasonic testing utilizes electromagnetic induction to generate ultrasonic waves in the material, analyzing the location, size, and type of defects by receiving reflected wave signals. It is non-contact and can detect deep defects, but its ability to detect thick-walled pipelines is insufficient, and its adaptability to defects in different directions is poor. Therefore, to compensate for the shortcomings of a single technology, a combined electromagnetic ultrasonic and MFL testing scheme has been adopted, which alleviates the aforementioned problems to some extent.

[0004] However, although related technologies have achieved simultaneous magnetic flux leakage detection and electromagnetic ultrasonic detection, the following problems still exist: 1. Because the existing magnet structure is unidirectionally magnetized, it can only detect defects in a single direction, resulting in the detection of cracks perpendicular to the magnetic field direction and the failure to detect cracks in other directions; 2. Due to unidirectional magnetization, only ultrasonic waves in a specific direction can be excited, which also limits the ability to detect cracks in different directions. Therefore, there is an urgent need for a new type of non-destructive testing equipment and method that can achieve multi-mode detection, has high detection accuracy, and is less prone to missing defects. Summary of the Invention

[0005] This application provides a composite sensor and detection method for pipeline non-destructive testing, which solves the problems of limited defect detection direction, high missed detection rate, and inability to achieve both high efficiency and high precision in existing pipeline non-destructive testing technologies due to unidirectional magnetization.

[0006] In a first aspect, embodiments of this application provide a composite sensor for non-destructive testing of pipelines, comprising:

[0007] A magnetic substrate; the magnetic substrate has a cylindrical structure; the first end face of the magnetic substrate includes an annular portion and a central portion located at the center of the annular portion; the magnetic properties of the annular portion and the central portion are opposite; the first end face is the side of the magnetic substrate facing the pipe under test when the composite sensor performs non-destructive testing on the pipe under test;

[0008] An electromagnetic ultrasonic coil is disposed on the first end face; the electromagnetic ultrasonic coil includes a first coil and a second coil that are intertwined; the first coil and the second coil are located in the same plane;

[0009] Multiple Hall elements are embedded between the annular portion and the central portion; the multiple Hall elements are evenly arranged circumferentially with the central portion as the center;

[0010] A controller electrically connected to the Hall element and the electromagnetic ultrasonic coil is configured to: generate a first control signal based on the leakage magnetic signal acquired by the Hall element; the first control signal is used to construct a target excitation circuit based on the electromagnetic ultrasonic coil, so that the target excitation circuit generates electromagnetic ultrasonic waves for detecting the pipe under test; and to acquire ultrasonic echoes based on the target excitation circuit, and generate detection results based on the leakage magnetic signal and the ultrasonic echoes.

[0011] Based on this scheme, the synergy between magnetic flux leakage detection of multi-directional defects and multi-mode ultrasonic excitation is realized, which significantly improves the detection coverage of crack defects in different directions, avoids the missed detection problem caused by traditional unidirectional magnetization, and improves the detection accuracy by fusing the two detection data.

[0012] In some embodiments, the first coil includes a first terminal and a second terminal, the first terminal being located on the outer ring of the electromagnetic ultrasonic coil and the second terminal being located on the inner ring of the electromagnetic ultrasonic coil;

[0013] The second coil includes a third terminal and a fourth terminal, wherein the third terminal is located in the inner ring of the electromagnetic ultrasonic coil and the fourth terminal is located in the outer ring of the electromagnetic ultrasonic coil;

[0014] The connection between the first terminal and the fourth terminal passes through the center of the electromagnetic ultrasonic coil; the connection between the second terminal and the third terminal passes through the center of the electromagnetic ultrasonic coil.

[0015] Based on this scheme, the propagation direction of ultrasonic waves (such as longitudinal waves and transverse waves) can be flexibly controlled by adjusting the electrical connection relationship of the terminals, thereby cooperating with the multidirectional magnetic field distribution of the magnetic substrate, further expanding the adaptability of the composite sensor to detect defects in different directions, and solving the limitation that traditional unidirectional magnetization can only excite ultrasonic waves in a specific direction.

[0016] In some embodiments, it also includes:

[0017] power supply;

[0018] A connector electrically connected to a power source; the connector is electrically connected to a first terminal, a second terminal, a third terminal, and a fourth terminal, respectively; the connector is configured to: based on a first control signal, switch the electrical connection relationship between the first terminal, the second terminal, the third terminal, the fourth terminal, and the power source to obtain different target excitation circuits.

[0019] In some embodiments, the target excitation circuit includes:

[0020] A first excitation circuit is used to generate a first electromagnetic ultrasonic longitudinal wave; in the first excitation circuit, the second terminal is electrically connected to the fourth terminal, and the first terminal and the third terminal are respectively electrically connected to the positive and negative poles of the power supply.

[0021] The second excitation circuit is used to generate electromagnetic ultrasonic shear waves; in the second excitation circuit, the second terminal is electrically connected to the third terminal, and the first terminal and the fourth terminal are electrically connected to the positive and negative terminals of the power supply, respectively.

[0022] The third excitation circuit is used to generate a second electromagnetic ultrasonic longitudinal wave; in the third excitation circuit, the first terminal is electrically connected to the fourth terminal, the second terminal is electrically connected to the third terminal, and the first terminal and the second terminal are respectively electrically connected to the positive and negative terminals of the power supply.

[0023] Based on this solution, the core problem of traditional testing being able to detect defects in only one direction is solved, realizing multi-dimensional and multi-directional defect detection capabilities, and significantly improving the comprehensiveness and accuracy of testing.

[0024] In some embodiments, the Hall element is provided in eight forms.

[0025] Secondly, this application also provides a pipeline non-destructive testing method, applied to the composite sensor for pipeline non-destructive testing described in the first aspect, the method comprising:

[0026] During the movement of the composite sensor inside the pipe under test, leakage magnetic signals are acquired based on Hall elements;

[0027] The ultrasonic scanning area is determined based on the magnetic flux leakage signal;

[0028] Electromagnetic ultrasound is used to scan the ultrasonic scanning area based on the electromagnetic ultrasound generated by the target excitation circuit, so as to obtain ultrasonic echo based on the target excitation circuit.

[0029] The detection results are generated based on the magnetic flux leakage signal and the ultrasonic echo.

[0030] Based on this scheme, the rapid positioning characteristic of magnetic flux leakage detection is used to narrow the ultrasonic scanning range, avoiding the redundancy of full-area scanning and improving detection efficiency. At the same time, by fusing the two detection data, the shortcomings of magnetic flux leakage detection (fast but low resolution) and ultrasonic detection (high resolution but time-consuming) are complemented, significantly improving the accuracy and reliability of detection.

[0031] In some embodiments, the magnetic flux leakage signal includes a Hall element code; the Hall element code corresponds to the defect within the circumferential angular range of the pipe under test; the step of determining the ultrasonic scanning area based on the magnetic flux leakage signal includes:

[0032] Extract the Hall element code from the leakage magnetic signal;

[0033] The circumferential angular range of the defect in the pipe under test is determined based on the Hall element encoding.

[0034] The circumferential angle range is defined as the ultrasound scanning area.

[0035] Based on this scheme, the encoding in the magnetic flux leakage signal can directly map the circumferential distribution range of the defect, allowing ultrasonic scanning to be performed only on this area, avoiding the waste of resources from full-circumference scanning. This design not only improves detection efficiency (reducing invalid scans) but also reduces the interference of background noise on ultrasonic echoes through precise positioning, thereby improving the signal-to-noise ratio of the scanning results and the accuracy of defect identification.

[0036] In some embodiments, the step of performing electromagnetic ultrasonic scanning on the ultrasonic scanning area based on electromagnetic ultrasonic waves generated by the target excitation circuit includes:

[0037] Within a preset time period, different target excitation circuits are cyclically switched to generate different electromagnetic ultrasound waves to perform electromagnetic ultrasound scanning on the ultrasound scanning area; the target excitation circuit includes a first excitation circuit for generating a first electromagnetic ultrasound longitudinal wave; a second excitation circuit for generating an electromagnetic ultrasound transverse wave; and a third excitation circuit for generating a second electromagnetic ultrasound longitudinal wave.

[0038] In some embodiments, before determining the ultrasonic scanning area based on the magnetic flux leakage signal, the method further includes:

[0039] Determine the validity of the leakage magnetic signal;

[0040] If the signal-to-noise ratio corresponding to the leakage magnetic signal exceeds a preset threshold, then the leakage magnetic signal is determined to be valid.

[0041] Based on this scheme, subsequent ultrasonic scanning is triggered only when the magnetic flux leakage signal is valid, avoiding meaningless scans caused by invalid signals and reducing detection time and energy consumption. This design improves the robustness of the method, ensuring that detection resources are used only for valid defect areas, further improving overall detection efficiency and the reliability of results.

[0042] In some embodiments, the method further includes:

[0043] While performing electromagnetic ultrasonic scanning on the ultrasonic scanning area, the leakage magnetic signal of the ultrasonic scanning area is acquired based on the Hall element;

[0044] A joint dataset was established based on magnetic flux leakage signals and ultrasonic echoes;

[0045] Cross-validation is performed based on data from the joint dataset.

[0046] The composite sensor provided in this application uses a ring-shaped magnet structure combined with circumferentially arranged Hall elements to achieve omnidirectional magnetic flux leakage detection. At the same time, through a specific combination of coil connection mode and timing control logic, it can accommodate multiple electromagnetic ultrasonic detection modes. This application improves the detection capability and accuracy of defects by combining preliminary magnetic flux leakage localization with precise ultrasonic orientation, effectively preventing missed detections. Attached Figure Description

[0047] Figure 1 A schematic diagram of the structure of a composite sensor for non-destructive testing of pipelines provided in an embodiment of this application;

[0048] Figure 2 A schematic diagram of the magnetic substrate in the composite sensor for non-destructive testing of pipelines provided in this application embodiment;

[0049] Figure 3 A schematic diagram of the electromagnetic ultrasonic coil in the composite sensor for non-destructive testing of pipelines provided in an embodiment of this application;

[0050] Figure 4 A cross-sectional view of the composite sensor provided in this application embodiment when performing non-destructive testing on the pipeline under test;

[0051] Figure 5 A control principle diagram of a composite sensor for non-destructive testing of pipelines provided in an embodiment of this application;

[0052] Figure 6 A wiring diagram of the first target excitation circuit provided in the embodiments of this application;

[0053] Figure 7 A wiring diagram of the second target excitation circuit provided in the embodiments of this application;

[0054] Figure 8 A wiring diagram of the third target excitation circuit provided in the embodiments of this application.

[0055] Wherein, 1-magnetic substrate; 11-first end face; 111-circular part; 112-center part; 2-electromagnetic ultrasonic coil; 21-first coil; 211-first terminal; 212-second terminal; 22-second coil; 221-third terminal; 222-fourth terminal; 3-Hall element; 100-tested pipe. Detailed Implementation

[0056] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0057] See Figure 1 This is a schematic diagram of the structure of a composite sensor for non-destructive testing of pipelines provided in an embodiment of this application; see also... Figure 2 This is a schematic diagram of the magnetic substrate in a composite sensor for non-destructive testing of pipelines provided in an embodiment of this application; see also... Figure 3 This is a schematic diagram of the electromagnetic ultrasonic coil in the composite sensor for non-destructive testing of pipelines provided in an embodiment of this application.

[0058] Depend on Figures 1 to 3 As can be seen, in some embodiments, the composite sensor for non-destructive testing of pipelines provided in this application may include:

[0059] Magnetic substrate 1; Magnetic substrate 1 is a cylindrical structure composed of cylindrical magnets, used to form a magnetic field; wherein, the side of magnetic substrate 1 facing the pipe 100 to be tested is defined as the first end face 11, the first end face 11 of magnetic substrate 1 is composed of a ring portion 111 and a central portion 112 located at the center of the ring portion 111, wherein the magnetic properties of the ring portion 111 and the central portion 112 are opposite, for example, the magnetic properties of the ring portion 111 are the S pole, and the magnetic properties of the central portion 112 are the N pole; when the composite sensor in the embodiment of this application is used to perform non-destructive testing on the pipe 100 to be tested, a magnetic field can be formed with the central portion 112 as the center and in the directions of each part of the ring portion 111.

[0060] In this embodiment, a magnet structure with a central N pole and an outer ring S pole is used to form a radially radiating three-dimensional magnetic field in the detection area. Compared with the traditional unidirectional magnetization method, the magnetic field coverage has no directional dead angles, ensuring that defects in any direction can generate detectable leakage magnetic signals.

[0061] See Figure 4 This is a cross-sectional view of the composite sensor provided in this application embodiment when performing non-destructive testing on the pipeline under test;

[0062] In some embodiments, the magnetic substrate 1 may be composed of a combination of multiple magnets, for example, see [link to relevant documentation]. Figure 4 The magnetic substrate 1 can be composed of a cylindrical magnet (with its N pole as the central part 112) and two annular magnets sequentially nested around it. The thicker annular magnet has its S pole as the ring part 111, while the thinner annular magnet connects the cylindrical magnet to the other annular magnet. The magnetic properties of the connecting parts between adjacent magnets are opposite. By assembling the magnetic substrate 1 using a magnet array, the unilateral magnetic field strength can be increased, thereby improving the ability to detect defects.

[0063] See Figure 2 The composite sensor provided in this application embodiment also includes a plurality of Hall elements 3 embedded between the annular portion 111 and the central portion 112; the plurality of Hall elements 3 are evenly arranged circumferentially with the central portion 112 as the center.

[0064] In this embodiment, the Hall element 3 is a sensor used to monitor the leakage magnetic field on the surface of the metal (the pipe under test 100) in real time. When there are defects such as cracks on the surface of the pipe under test 100, a leakage magnetic field will be formed at the defect location. The Hall element 3 can capture and record information such as the position and direction of the leakage magnetic field, thereby realizing leakage magnetic field detection. Since the central part 112 and the annular part 111 form a ring magnetization structure, a magnetic field in all directions from the center to the outside can be generated. At the same time, multiple Hall elements 3 are arranged circumferentially, which can monitor the changes in magnetic field in different directions individually, thereby enabling comprehensive detection of cracks and defects that may exist in the pipe under test in various directions, avoiding missed detections.

[0065] In some embodiments, to further reduce the probability of missed detection, the number of Hall elements 3 can be designed according to actual needs. For example, the number can be set to 8, 16, or other quantities to more accurately obtain the specific location of the defect and perform other subsequent precise controls. The Hall elements 3 are distributed along the circumference at equal angles, and each Hall sensor independently collects magnetic field distortion data in the corresponding direction. Through a multi-channel synchronous sampling algorithm, omnidirectional identification of 0.1mm-level cracks can be achieved, and the detection sensitivity remains consistent for cracks at any angle to the magnetic field direction (including blind zone cracks parallel to traditional unipolar magnetic fields).

[0066] In some embodiments, when detecting inside a pipeline, the composite sensor provided in this application achieves static detection through an omnidirectional sensing architecture, which can reduce the problem of failure to detect due to malfunctions of moving parts compared to traditional solutions.

[0067] See Figure 1 and Figure 3 The composite sensor provided in this application embodiment also includes an electromagnetic ultrasonic coil 2 disposed on the first end face 11. When a high-frequency current is passed through the electromagnetic ultrasonic coil 2, eddy currents can be formed in the pipe to be tested. Under the action of an external magnetic field, it will be subjected to mechanical force and generate high-frequency vibration, forming ultrasonic waves, thereby realizing the function of electromagnetic ultrasonic detection.

[0068] The electromagnetic ultrasonic coil 2 produces electromagnetic ultrasonic waves with different morphologies under different excitation methods, resulting in different detection functions. To ensure that the composite sensor provided in this embodiment can accommodate multiple detection modes, see [link to relevant documentation]. Figure 3 The electromagnetic ultrasonic coil 2 may include a first coil 21 and a second coil 22 that are intertwined; wherein the first coil 21 and the second coil 22 are located in the same plane. In this application, by using two sets of coils intertwined, the switching between different detection modes can be achieved without changing the mechanical structure, and the composite sensor can also achieve multi-mode detection during the detection process through program control.

[0069] In some embodiments, the electromagnetic ultrasonic coil 2 may have a multi-layer structure, wherein each layer includes a first coil 21 and a second coil 22 that are intertwined. In this embodiment, a single-layer structure is used as an example to illustrate its function. It should be understood that the multi-layer structure can be regarded as a superposition of the single-layer structure, and it also has the function of achieving the same function or improving the corresponding effect.

[0070] In this embodiment, the electromagnetic ultrasonic coil 2, being disposed on the first end face 11, can utilize leakage magnetic field detection to generate a magnetic field for electromagnetic ultrasonic monitoring. In other words, the magnetic substrate 1 serves as the excitation magnet for the electromagnetic ultrasonic coil 2, thereby integrating the two detection methods while reducing the overall space occupied by the sensor.

[0071] See Figure 5 This is a control principle diagram of a composite sensor for non-destructive testing of pipelines provided in an embodiment of this application.

[0072] like Figure 5As shown, the composite sensor provided in this application embodiment also includes a controller electrically connected to the Hall element 3 and the electromagnetic ultrasonic coil 2 respectively. The controller is configured to: generate a first control signal based on the leakage magnetic signal acquired by the Hall element 3; the first control signal is used to construct a target excitation circuit based on the electromagnetic ultrasonic coil 2, so that the target excitation circuit forms electromagnetic ultrasonic waves for detecting the pipe 100 under test; and to acquire ultrasonic echoes based on the target excitation circuit, and generate detection results based on the leakage magnetic signal and the ultrasonic echoes.

[0073] In this embodiment, to perform multi-mode electromagnetic ultrasonic testing on the pipeline 100 under test, different target excitation circuits can be constructed based on the electromagnetic ultrasonic coils 2, thereby generating electromagnetic ultrasonic waves of different forms using different circuit properties. Specifically, different target excitation circuits can be constructed by changing the circuit connection relationship between the first coil 21 and the second coil 22 and the power supply.

[0074] See Figure 3 and Figure 5 In some feasible embodiments, the first coil 21 may include a first terminal 211 and a second terminal 212, with the first terminal 211 located on the outer ring of the electromagnetic ultrasonic coil 2 and the second terminal 212 located on the inner ring of the electromagnetic ultrasonic coil 2.

[0075] The second coil 22 may include a third terminal 221 and a fourth terminal 222, with the third terminal 221 located in the inner ring of the electromagnetic ultrasonic coil 2 and the fourth terminal 222 located in the outer ring of the electromagnetic ultrasonic coil 2.

[0076] The connection between the first terminal 211 and the fourth terminal 222 passes through the center of the electromagnetic ultrasonic coil 2; the connection between the second terminal 212 and the third terminal 221 passes through the center of the electromagnetic ultrasonic coil 2.

[0077] In some feasible embodiments, see Figure 5 The composite sensor also includes:

[0078] Power supply; the output voltage, frequency and other parameters of the power supply can be adjusted by the controller;

[0079] A connector electrically connected to a power source; in this embodiment, the connector is used to adjust the wiring relationship between each coil connector and the power source based on a first control command sent by the controller. The connector can be equipped with multiple electrical switches. When the connector is electrically connected to the first terminal 211, the second terminal 212, the third terminal 221, and the fourth terminal 222 respectively, it can connect or disconnect any two terminals. At the same time, it can also connect any terminal to one of the positive or negative poles of the power source. Therefore, the connector can be configured to switch the electrical connection relationship between the first terminal 211, the second terminal 212, the third terminal 221, the fourth terminal 222 and the power source based on the first control signal to obtain different target excitation circuits.

[0080] See Figure 6 This is a wiring diagram of the first target excitation circuit provided in the embodiments of this application;

[0081] In some feasible embodiments, the target excitation circuit includes:

[0082] The first excitation circuit is used to generate a first electromagnetic ultrasonic longitudinal wave. In the first excitation circuit, the second terminal 212 and the fourth terminal 222 are electrically connected, and the first terminal 211 and the third terminal 221 are electrically connected to the positive and negative terminals of the power supply, respectively. At this time, the first coil 21 and the second coil 22 are connected in series. When a high-frequency current is applied to the coils, the current in the first coil 21 and the second coil 22 are in the same direction, which will generate eddy currents in the pipe 100 under test. Under the action of the external magnetic field (the magnetic field formed by the magnetic substrate 1), a vertically propagating electromagnetic ultrasonic longitudinal wave will be generated to detect wall thickness and internal metal defects. This mode is mainly used to detect wall thickness and internal defects, and the sound wave penetration depth is increased by 40% compared with the traditional single-coil structure.

[0083] See Figure 7 This is a wiring diagram of the second target excitation circuit provided in the embodiments of this application;

[0084] In some feasible embodiments, the target excitation circuit further includes:

[0085] The second excitation circuit is used to generate electromagnetic ultrasonic shear waves. In this circuit, the second terminal 212 is electrically connected to the third terminal 221, and the first terminal 211 and the fourth terminal 222 are electrically connected to the positive and negative terminals of the power supply, respectively. At this time, the first coil 21 and the second coil 22 are connected in series. When a high-frequency current is applied to the coils, the currents in the first coil 21 and the second coil 22 flow in opposite directions. Under the influence of an external magnetic field, horizontally propagating SH waves or Lamb waves are formed, used to detect defects and cracks. In this state, since both the coils and the magnet are circular, cracks in all directions can be detected, avoiding missed detections. Phase control technology enables 360° circular scanning, making it particularly suitable for circumferential crack detection.

[0086] See Figure 8 This is a wiring diagram of the third target excitation circuit provided in the embodiments of this application;

[0087] In some feasible embodiments, the target excitation circuit further includes:

[0088] The third excitation circuit is used to generate the second electromagnetic ultrasonic longitudinal wave. In the third excitation circuit, the first terminal 211 is electrically connected to the fourth terminal 222, the second terminal 212 is electrically connected to the third terminal 221, and the first terminal 211 and the second terminal 212 are electrically connected to the positive and negative poles of the power supply, respectively. At this time, the first coil 21 and the second coil 22 are connected in parallel. When a high-frequency current is applied to the coil, the current in the first coil 21 and the second coil 22 are in the same direction, still forming a vertically propagating electromagnetic ultrasonic longitudinal wave. However, the current is enhanced at this time, increasing the propagation capability, so as to be suitable for measuring larger wall thicknesses.

[0089] It should be noted that, in the embodiments of this application, when the number of coils constituting the electromagnetic ultrasonic coil 2 is more than two, the specific form of the target excitation circuit is not limited to the above three types, and will not be described in detail here.

[0090] In some embodiments, when the controller receives the leakage magnetic signal acquired by the Hall element 3, it determines that there is a defect area on the pipe 100 under test. At this time, the controller can immediately start electromagnetic ultrasonic testing and specify one of the above-mentioned multiple testing modes to perform electromagnetic ultrasonic testing.

[0091] In some embodiments, in order to detect all possible defects at once, that is, to enable the composite sensor of this application to simultaneously handle multiple detection modes, the controller can be configured to: through time-domain control, excite the above three connection modes respectively within a unit time. Specifically, the first control command sent by the controller to the connector can be divided into four sub-control commands. The first sub-control command is used to immediately construct the first excitation circuit to form a first electromagnetic ultrasonic longitudinal wave to perform electromagnetic ultrasonic detection on the pipe 100 under test; the second sub-control command is used to construct the second excitation circuit to form an electromagnetic ultrasonic transverse wave to perform electromagnetic ultrasonic detection on the pipe 100 under test after a preset time (t1) of electromagnetic ultrasonic detection by the first excitation circuit; the third sub-control command is used to construct the third excitation circuit to form a second electromagnetic ultrasonic longitudinal wave to perform electromagnetic ultrasonic detection on the pipe 100 under test after a preset time (t1) of electromagnetic ultrasonic detection by the second excitation circuit; and the fourth sub-control command is used to reconstruct the first excitation circuit after a preset time (t1) of electromagnetic ultrasonic detection by the third excitation circuit. By repeatedly executing the above steps, the electromagnetic ultrasonic testing mode can be switched periodically, allowing the composite sensor to simultaneously acquire detection results from multiple modes during the testing process. This embodiment alternately excites different detection modes in the time domain, and combined with an adaptive signal fusion algorithm, enables the acquisition of three-dimensional defect information in a single scan, improving detection efficiency by three times compared to step-by-step scanning.

[0092] As can be seen from the above technical solution, the main working process of the composite sensor provided in this application includes:

[0093] I. Initial Detection Phase (Rapid Magnetic Flux Leakage Scan).

[0094] Omnidirectional magnetic flux leakage detection: When the composite sensor moves along the detection surface of the pipe 100 under test, the ring magnet structure forms a radial radiating magnetic field on the metal surface, and eight (or more) Hall elements 3 monitor the magnetic field changes in their respective directions in real time.

[0095] Preliminary Defect Location: When a Hall sensor in a certain direction detects magnetic field distortion (such as a sudden change in amplitude or abnormal waveform), it immediately records the leakage magnetic signal.

[0096] Location information (which can be calculated from an encoder or motion trajectory);

[0097] Orientation characteristics (the crack direction is determined based on the physical location of the Hall sensor, such as 30°, 120°, etc.);

[0098] Intensity level (quantification of leakage magnetic field distortion).

[0099] II. Automatically triggered directional electromagnetic ultrasound scanning.

[0100] Intelligent mode switching: The controller can determine the validity of the leakage magnetic signal through a configured real-time signal processing unit (such as FPGA / DSP). If it exceeds a preset threshold (such as signal-to-noise ratio > 3:1), then:

[0101] Target area identification: Determine the circumferential angle range of the defect based on the Hall sensor number (e.g., the defect location corresponding to the signal detected by Hall element 3, number H3, is located in the 45°~90° sector).

[0102] Dynamic configuration of electromagnetic ultrasound: Based on the automatic switching of coil connection mode by the connector (such as selecting the SH wave mode of "2, 3 connected, 1, 4 powered"), and adjusting the excitation frequency and power of the power supply, the horizontally propagating ultrasonic waves in the sector are directionally excited.

[0103] Focused scanning: By controlling delayed emission (if multi-element excitation is supported), ultrasonic energy is concentrated to cover the suspected area, improving the signal-to-noise ratio.

[0104] III. Cross-validation of multiphysics data.

[0105] Synchronous data acquisition: While performing electromagnetic ultrasound scanning, the Hall sensors in the corresponding directions are continuously monitored to form a spatiotemporally aligned joint dataset.

[0106] When generating detection results, the controller can use feature cross-validation:

[0107] Magnetic leakage signal: provides information on the location and orientation of defects (but is not sensitive to depth);

[0108] Ultrasonic echo: provides information on the depth, size, and type of defects (such as the diffraction characteristics of crack tips).

[0109] IV. Output and Feedback.

[0110] The controller can perform three-dimensional modeling of defects. Specifically, it can integrate leakage magnetic direction angle and ultrasonic depth data to generate a defect model with a direction vector (the display of the detection result is, for example, "60° oblique crack, depth 4.2mm").

[0111] Furthermore, in some other embodiments, the controller may also have a built-in defect direction classification module that can automatically output crack orientation angles (0-360° continuous range) to provide key parameters for structural safety assessment.

[0112] As can be seen from the above technical solution, the composite sensor provided in this application can achieve omnidirectional magnetic leakage detection by using a ring-shaped magnet structure combined with circumferentially arranged Hall elements; at the same time, through a specific combination of coil connection mode and timing control logic, it can accommodate multiple electromagnetic ultrasonic detection modes; this application improves the detection capability and accuracy of defects by using a collaborative detection step of preliminary magnetic leakage localization + precise ultrasonic orientation, effectively preventing missed detections.

[0113] This application also provides a pipeline non-destructive testing method, applied to the composite sensor for pipeline non-destructive testing described in any of the foregoing embodiments, the method comprising:

[0114] S100: During the movement of the composite sensor inside the pipe under test, leakage magnetic signal is acquired based on Hall element;

[0115] S200: Determine the ultrasonic scanning area based on the magnetic flux leakage signal;

[0116] S300: Electromagnetic ultrasound scans the ultrasonic scanning area based on the electromagnetic ultrasound generated by the target excitation circuit, so as to obtain ultrasonic echoes based on the target excitation circuit;

[0117] S400: Generates detection results based on magnetic flux leakage signal and ultrasonic echo.

[0118] In some feasible embodiments, the magnetic flux leakage signal includes a Hall element code; the Hall element code corresponds to the defect within the circumferential angular range of the pipe under test; the step of determining the ultrasonic scanning area based on the magnetic flux leakage signal includes:

[0119] S210: Extract the Hall element code from the leakage magnetic signal; the Hall code is used to distinguish Hall elements located in different positions. In some examples, the Hall code can represent the orientation information of the Hall element, such as 0, 30, 60, etc., which are used to represent the angle of the Hall element.

[0120] S220: Determine the circumferential angle range of the defect in the pipe under test based on Hall element encoding; for example, if the Hall elements at both 0° and 30° positions capture leakage magnetic signals, it indicates that the defect location may be between 0° and 30°.

[0121] S230: Define the circumferential angle range as the ultrasound scanning area.

[0122] In some feasible embodiments, the step of performing electromagnetic ultrasonic scanning on the ultrasonic scanning area based on the electromagnetic ultrasonic waves generated by the target excitation circuit includes:

[0123] S310: Within a preset time period, different target excitation circuits are cyclically switched to generate different electromagnetic ultrasound waves to perform electromagnetic ultrasound scanning on the ultrasound scanning area; the target excitation circuit includes a first excitation circuit for generating a first electromagnetic ultrasound longitudinal wave; a second excitation circuit for generating an electromagnetic ultrasound transverse wave; and a third excitation circuit for generating a second electromagnetic ultrasound longitudinal wave.

[0124] In some feasible embodiments, the method further includes, before determining the ultrasonic scanning area based on the magnetic flux leakage signal:

[0125] S110: Determine the validity of the leakage magnetic signal;

[0126] S120: If the signal-to-noise ratio corresponding to the leakage magnetic signal exceeds the preset threshold, the leakage magnetic signal is determined to be valid.

[0127] In some feasible embodiments, the method further includes:

[0128] S320: While performing electromagnetic ultrasonic scanning on the ultrasonic scanning area, the leakage magnetic signal of the ultrasonic scanning area is acquired based on the Hall element.

[0129] S330: Establishing a joint dataset based on leakage magnetic field signals and ultrasonic echoes;

[0130] S340: Perform cross-validation based on data from the joint dataset.

[0131] In this embodiment of the application, when a Hall sensor detects a signal in a certain direction, an electromagnetic ultrasonic directional scan of that area can be automatically triggered, and the false alarm rate can be reduced through multi-physics data mutual verification.

[0132] The effects of the method provided in this application embodiment on practical applications are described in the foregoing device embodiments and will not be repeated here.

[0133] Using the composite sensor and detection method provided in the embodiments of this application, the detection process in practical applications can be as follows:

[0134] The composite sensor provided in this application is mounted on a carrier, which is then placed into the pipe to be tested. Due to the pressure difference between the front and rear, the carrier moves forward in the pipe. During this movement, the composite sensor records data. After the sensor is removed, the data recorded by the composite sensor is analyzed and processed by a host computer.

[0135] It could also be:

[0136] Using the composite sensor provided in this application, along with a data acquisition system and a handheld device, external inspection operations can be performed on pipelines.

[0137] It is readily understood that, based on the several embodiments provided in this application, those skilled in the art can combine, split, or reorganize the embodiments of this application to obtain other embodiments, none of which exceed the protection scope of this application.

[0138] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A composite sensor for non-destructive testing of pipelines, characterized in that, include: A magnetic substrate; the magnetic substrate has a cylindrical structure; the first end face of the magnetic substrate includes an annular portion and a central portion located at the center of the annular portion; the magnetic properties of the annular portion and the central portion are opposite; the first end face is the side of the magnetic substrate facing the pipe under test when the composite sensor performs non-destructive testing on the pipe under test; An electromagnetic ultrasonic coil is disposed on the first end face; the electromagnetic ultrasonic coil includes a first coil and a second coil that are intertwined; the first coil and the second coil are located in the same plane; Multiple Hall elements are embedded between the annular portion and the central portion; the multiple Hall elements are evenly arranged circumferentially with the central portion as the center; A controller electrically connected to the Hall element and the electromagnetic ultrasonic coil is configured to: generate a first control signal based on the leakage magnetic signal acquired by the Hall element; the first control signal is used to construct a target excitation circuit based on the electromagnetic ultrasonic coil, so that the target excitation circuit generates electromagnetic ultrasonic waves for detecting the pipe under test; and to acquire ultrasonic echoes based on the target excitation circuit, and generate detection results based on the leakage magnetic signal and the ultrasonic echoes. The first coil includes a first terminal and a second terminal, the first terminal being located on the outer ring of the electromagnetic ultrasonic coil and the second terminal being located on the inner ring of the electromagnetic ultrasonic coil. The second coil includes a third terminal and a fourth terminal, wherein the third terminal is located in the inner ring of the electromagnetic ultrasonic coil and the fourth terminal is located in the outer ring of the electromagnetic ultrasonic coil; The connection between the first terminal and the fourth terminal passes through the center of the electromagnetic ultrasonic coil; the connection between the second terminal and the third terminal passes through the center of the electromagnetic ultrasonic coil. Also includes: power supply; A connector electrically connected to a power source; the connector is electrically connected to a first terminal, a second terminal, a third terminal, and a fourth terminal, respectively; the connector is configured to: based on a first control signal, cyclically switch the electrical connection relationships between the first terminal, the second terminal, the third terminal, the fourth terminal, and the power source to obtain different target excitation circuits; The target excitation circuit includes: A first excitation circuit is used to generate a first electromagnetic ultrasonic longitudinal wave; in the first excitation circuit, the second terminal is electrically connected to the fourth terminal, and the first terminal and the third terminal are respectively electrically connected to the positive and negative poles of the power supply. The second excitation circuit is used to generate electromagnetic ultrasonic shear waves; in the second excitation circuit, the second terminal is electrically connected to the third terminal, and the first terminal and the fourth terminal are electrically connected to the positive and negative terminals of the power supply, respectively. The third excitation circuit is used to generate a second electromagnetic ultrasonic longitudinal wave; in the third excitation circuit, the first terminal is electrically connected to the fourth terminal, the second terminal is electrically connected to the third terminal, and the first terminal and the second terminal are respectively electrically connected to the positive and negative terminals of the power supply.

2. The composite sensor for non-destructive testing of pipelines according to claim 1, characterized in that, The Hall element is provided in eight parts.

3. A method for non-destructive testing of pipelines, applied to the composite sensor for non-destructive testing of pipelines as described in claim 1 or 2, characterized in that, The method includes: During the movement of the composite sensor inside the pipe under test, leakage magnetic signals are acquired based on Hall elements; The ultrasonic scanning area is determined based on the magnetic flux leakage signal; Electromagnetic ultrasound is used to scan the ultrasonic scanning area based on the electromagnetic ultrasound generated by the target excitation circuit, so as to obtain ultrasonic echo based on the target excitation circuit. The detection results are generated based on the magnetic flux leakage signal and the ultrasonic echo.

4. The pipeline non-destructive testing method according to claim 3, characterized in that, The leakage magnetic signal includes Hall element encoding; The Hall element encodes the defect within the circumferential angular range of the pipe under test; the step of determining the ultrasonic scanning area based on the magnetic flux leakage signal includes: Extract the Hall element code from the leakage magnetic signal; The circumferential angular range of the defect in the pipe under test is determined based on the Hall element encoding. The circumferential angle range is defined as the ultrasound scanning area.

5. The pipeline non-destructive testing method according to claim 4, characterized in that, The steps of performing electromagnetic ultrasonic scanning of the ultrasonic scanning area based on electromagnetic ultrasonic waves generated by the target excitation circuit include: Within a preset time period, different target excitation circuits are cyclically switched to generate different electromagnetic ultrasound waves to perform electromagnetic ultrasound scanning on the ultrasound scanning area; the target excitation circuit includes a first excitation circuit for generating a first electromagnetic ultrasound longitudinal wave; a second excitation circuit for generating an electromagnetic ultrasound transverse wave; and a third excitation circuit for generating a second electromagnetic ultrasound longitudinal wave.

6. The pipeline non-destructive testing method according to claim 5, characterized in that, Before determining the ultrasonic scanning area based on the magnetic flux leakage signal, the method further includes: Determine the validity of the leakage magnetic signal; If the signal-to-noise ratio corresponding to the leakage magnetic signal exceeds a preset threshold, then the leakage magnetic signal is determined to be valid.

7. The pipeline non-destructive testing method according to claim 5, characterized in that, The method further includes: While performing electromagnetic ultrasonic scanning on the ultrasonic scanning area, the leakage magnetic signal of the ultrasonic scanning area is acquired based on the Hall element; A joint dataset was established based on magnetic flux leakage signals and ultrasonic echoes; Cross-validation is performed based on data from the joint dataset.

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