A phased array ultrasonic testing method and system for small nozzle detection

Abstract

The application discloses a phased array ultrasonic detection method and system for small nozzle detection, and relates to the technical field of nondestructive testing. The method comprises the following steps: constructing a parameterized digital model of a target nozzle weld; at each scanning position of a phased array probe, determining surface contour information of the target nozzle weld at each scanning position by performing phased array scanning on the target nozzle weld; determining an adaptive focusing rule at each scanning position according to the surface contour information and the parameterized digital model; the adaptive focusing rule comprises a scanning mode and an adaptive delay parameter; at each scanning position, performing adaptive phased array scanning on the target nozzle weld according to the adaptive focusing rule to obtain scanning data of the target nozzle weld at each scanning position; and obtaining a detection image of the target nozzle weld according to the scanning data of the target nozzle weld at all scanning positions. The application can adapt to the complex geometry of a small nozzle and realize accurate and adaptive sound beam control.

Description

Technical Field

[0001] This application relates to the field of nondestructive testing technology, and in particular to a phased array ultrasonic testing method and system for testing small tubes. Background Technology

[0002] In industries such as nuclear power, petrochemicals, and electric power, the weld seams of small connecting pipes are critical structures in pressure-bearing equipment, and their internal quality directly affects the safe operation of the equipment. Phased array ultrasonic testing technology is increasingly widely used in the inspection of such weld seams due to its flexibility, high efficiency, and intuitive imaging advantages. However, small connecting pipes have complex geometries (curvature and spatial constraints), and traditional phased array testing uses a fixed focusing rule, which is usually based on the assumption of flat or highly curved workpieces. When applied to small connecting pipes, the fixed delay rule cannot adapt to the differences in the sound beam path caused by curvature variations, resulting in distortion and energy defocusing of the sound waves as they propagate within the workpiece. This severely reduces the sensitivity and signal-to-noise ratio of the detection, especially its insufficient detection capability and quantitative accuracy for highly hazardous planar defects (such as lack of fusion and cracks).

[0003] Therefore, there is an urgent need for a technology that can adapt to the complex geometry of small connecting pipes and achieve precise focusing across the entire detection area to improve the reliability of detection. Summary of the Invention

[0004] The purpose of this application is to provide a phased array ultrasonic testing method and system for small tube inspection, which can adapt to the complex geometry of the small tube and achieve precise and adaptive acoustic beam control.

[0005] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a phased array ultrasonic testing method for small tube inspection, comprising: Construct a parametric digital model of the target weld joint; At each preset scanning position of the phased array probe, the surface contour information of the target pipe weld is determined by performing phased array scanning on the target pipe weld at each scanning position. Based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, an adaptive focusing rule is determined for each scanning position; the adaptive focusing rule includes the scanning mode and adaptive delay parameters. At each scanning position, an adaptive phased array scan is performed on the target nozzle weld according to the adaptive focusing rule at each scanning position to obtain the scanning data of the target nozzle weld at each scanning position; Based on the scanning data of the target nozzle weld at all scanning positions, the inspection image of the target nozzle weld is obtained.

[0006] Secondly, this application provides a phased array ultrasonic testing system for small tube testing, including: a phased array probe, a data acquisition unit, a surface profile analysis module, an adaptive focusing module, and a delay control module; The phased array probe is set at each preset scanning position. The surface profile analysis module controls the phased array probe to emit ultrasonic signals to the target pipe through the acquisition unit and receives the ultrasonic echo signals generated by the weld of the target pipe. The acquisition unit is used to convert the ultrasonic echo signals into digital ultrasonic shape data. The surface profile analysis module is used to determine the surface profile information of the weld of the target pipe at each scanning position based on the digital ultrasonic shape data. The adaptive focusing module is used to determine the adaptive focusing rule for each scanning position based on the surface contour information and parametric digital model of the weld seam of the target pipe at each scanning position; the adaptive focusing rule includes the scanning mode and adaptive delay parameter; The delay control module is used to receive the adaptive focusing rule and, according to the adaptive focusing rule at each scanning position, control the phased array probe through the acquisition unit to perform adaptive phased array scanning on the target nozzle weld, thereby obtaining the scanning data of the target nozzle weld at each scanning position; and obtain the detection image of the target nozzle weld based on the scanning data of the target nozzle weld at all scanning positions.

[0007] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a phased array ultrasonic testing method and system for inspecting small-diameter pipe welds. By determining an adaptive focusing rule at each scanning position, adaptive phased array scanning is performed on the target pipe weld, effectively compensating for the influence of the small-diameter pipe curvature on the sound beam propagation. This ensures that the sound beam remains well focused within the inspection area, eliminating dead zones and improving inspection accuracy. Therefore, this application can adapt to the complex geometry of small-diameter pipe welds, achieving precise and adaptive sound beam control. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 A schematic flowchart of a phased array ultrasonic testing method for detecting small tubes provided in an embodiment of this application; Figure 2 A schematic diagram illustrating the configuration of focusing rules in surface profile analysis provided in this application embodiment; Figure 3A schematic diagram of ray tracing for determining the aperture center in a sector scan, provided for an embodiment of this application; Figure 4 This application provides a schematic diagram of the signal transmission of a phased array ultrasonic testing system for small tube testing, as shown in the embodiments of this application. Figure 5 This is a schematic diagram of a phased array ultrasonic testing system for small tube inspection, provided as an embodiment of this application.

[0010] Reference numerals: Phased array probe-1, Acquisition unit-2, Phased array system-3, Test target-4, Target surface-5, Fillet weld-6, Surface profile analysis module-7, Adaptive focusing module-8, Delay control module-9, First linear scan-11, Second linear scan-12, Effective probe surface-13, First array element-14, Second array element-15, Beam intersection-50, First acoustic beam-51, Second acoustic beam-52, Vertical plane-53, First acoustic beam refraction angle-510, Second acoustic beam refraction angle-520, First focal point-511, Second focal point-512, First surface portion-61, Second surface portion-62. Detailed Implementation

[0011] The technical solutions of 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 of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0012] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] In one exemplary embodiment, such as Figure 1 As shown, a phased array ultrasonic testing method for small tube detection is provided, including the following steps 101 to 105.

[0014] Step 101: Construct a parametric digital model of the target nozzle weld.

[0015] Step 102: At each preset scanning position of the phased array probe, the surface contour information of the target pipe weld is determined by performing phased array scanning on the target pipe weld at each scanning position.

[0016] Step 103: Based on the surface contour information and parametric digital model of the target pipe weld at each scanning position, determine the adaptive focusing rule for each scanning position; the adaptive focusing rule includes the scanning mode and adaptive delay parameter.

[0017] Step 104: At each scanning position, perform adaptive phased array scanning on the target nozzle weld according to the adaptive focusing rule at each scanning position to obtain the scanning data of the target nozzle weld at each scanning position.

[0018] Step 105: Obtain the inspection image of the target nozzle weld based on the scanning data of the target nozzle weld at all scanning positions.

[0019] Implementing steps 101 to 105 overcomes the problems of beam distortion and uneven sensitivity caused by the traditional fixed focusing method under the complex geometry of the small tube, eliminates the detection dead zone, and improves detection accuracy and efficiency.

[0020] In another exemplary embodiment of this application, step 101 above constructs a parametric digital model of the small pipe weld, which includes at least the diameter of the main pipe and the pipe, the wall thickness, the bevel angle, the weld width, and the material acoustic properties.

[0021] In another exemplary embodiment of this application, step 102 described above may be replaced by steps 201 to 206.

[0022] Step 201: At each preset scanning position of the phased array probe, control the phased array probe to perform phased array scanning of the target pipe weld at different turning angles to obtain ultrasonic echo data at each scanning position.

[0023] Phased array scanning can be performed using either linear or sector scanning. For example, at least two linear phased array scans with different steering angles (i.e., the angle between the acoustic beam and the target nozzle surface) are performed to acquire data. Using multiple beams at different angles for contour analysis is beneficial for more accurately acquiring surface information of complex geometries.

[0024] By analyzing this set of scans (e.g.) Figure 2 The acoustic data obtained from the scan shown can be processed to analyze the contour of the entire target surface 5 reached by the sound beam. For example, the data from the first linear scan 11 can be used for analysis. Figure 2 The contour of the first surface portion 61 is defined because the sound beam is approximately perpendicular to these regions. Data from the second linear scan 12 can then be used for analysis. Figure 2 The contour of the second surface portion 62 is then determined. Finally, by integrating contour analysis information from multiple scans, a complete and relevant surface contour can be reconstructed.

[0025] Step 202: Identify and extract valid echo data from the ultrasound echo data at each scanning position.

[0026] Data localization and filtering: First, strong interface echo signals from the inner and outer walls of the main and branch pipes are identified and extracted from the received ultrasonic echo data (A-scan data). This is usually achieved through sound path estimation based on the probe position.

[0027] Step 203: Determine the sound wave propagation path length based on each valid echo data.

[0028] Step 204: Based on the sound wave propagation path length, calculate the coordinates in space of the surface feature point corresponding to each valid echo data through geometric relationships.

[0029] Feature point coordinate calculation: For each identified valid echo data, the sound wave propagation path length is calculated based on its precise transit time and known sound speed. Then, combined with the current emission angle and position of the sound beam (determined by the probe coordinates and the sound beam deflection law), the two-dimensional or three-dimensional coordinates of the surface feature point corresponding to the echo in space are calculated through geometric relationships (such as triangulation).

[0030] Step 205: Arrange the coordinates of all the calculated surface feature points in space in spatial order, and use a curve fitting algorithm to generate the surface profile curve of the target pipe weld.

[0031] Contour curve fitting: The coordinates of multiple discrete surface feature points calculated in the above steps are arranged in spatial order. Then, the program calls a standard curve fitting algorithm to generate a smooth, continuous curve, which represents the surface contour model of the detected area.

[0032] Step 206: Determine the geometric parameters in the surface profile curve of the target nozzle weld and use them as the surface profile information of the target nozzle weld at each scanning position.

[0033] Key geometric parameter output: Based on the fitted contour curve, the program further calculates and outputs key parameters to guide subsequent focusing, such as the position of the weld fusion line, and most importantly, the surface tangential angle and normal direction at any target focus point on the contour.

[0034] In another exemplary embodiment of this application, for simple geometries, the parameters of the focusing law (such as focal length and beam refraction angle for linear scanning, and the angle range for sector scanning) are typically defined directly by the user. Beam spacing is used to define the scanning resolution. In this embodiment, focal length, beam refraction angle, and beam spacing are the primary beam parameters, and these parameters are relative to... Figure 2 The target surface 5 shown is defined by the nominal reference surface.

[0035] The adaptive focusing rule includes a scanning mode and an adaptive delay parameter. The scanning mode includes linear scanning and sector scanning, and the adaptive delay parameter is the transmit delay parameter / receive delay parameter. Therefore, step 103 above can be replaced by steps 301 to 307.

[0036] Step 301: When the outer wall of the main pipe is perpendicular to the branch pipe in the parametric digital model, the scanning mode is determined to be linear scanning.

[0037] Step 302: When the outer wall of the main pipe is not perpendicular to the branch pipe in the parametric digital model, determine the scanning mode as sector scan.

[0038] When there is an angle change between the outer wall of the main pipe and the branch pipe, the system will preferentially use sector scanning.

[0039] Both scanning modes are achieved by precisely controlling the emission delay time of each chip in the probe.

[0040] Linear scanning is achieved by sequentially translating a group of crystals in the excitation probe at fixed steps (i.e., the positions of the activated crystals move sequentially), while applying a delay law to each crystal to achieve vertical incidence or fixed-angle deflection. This is equivalent to electronically moving the emission position of the sound beam to scan along a straight line.

[0041] The formation of sector scanning: Under the premise of a fixed set of excitation crystals, the deflection angle of the synthesized sound beam is continuously varied within a certain range by continuously changing the delay time applied to each crystal. This enables scanning at different angles starting from a fixed position.

[0042] Step 303: Based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, trace the ultrasonic ray path backward from the focal position to the target nozzle surface, and apply Snell's law at the interface of the target nozzle surface to trace back to the element of phased array probe 1.

[0043] In one example, when the scanning mode is fan-shaped scanning, the beam of the fan-shaped scan is configured to enter the test object, forming an angle with an imaginary vertical plane 53, which is perpendicular to the reference surface and passes through an intersection on the reference surface, the intersection being defined by the user according to the testing specifications; the beam extends towards the effective surface 13 of the probe, intersecting with the test surface of the geometric profile, and reaches the element of the probe at a specific incident angle according to Snell's law, the element being defined as the center of the aperture. The detailed implementation of step 303 is as follows: a beam intersection 50 is defined on the surface of the target nozzle of the parameterized digital model; the beam intersection 50 is located in the vertical direction of the target nozzle surface; multiple acoustic beams are virtually generated from the beam intersection 50 into the interior of the target nozzle, intersecting with the weld surface of the target nozzle to form a focal point; reverse acoustic beamline tracing is performed from the focal point, and Snell's law is applied at the interface of the target nozzle surface to trace back to the element of the phased array probe 1.

[0044] As attached Figure 3 The fan-shaped scan defined by the diagram uses a focusing rule. In this adaptive fan-shaped scan, a beam intersection 50 is defined. The beam intersection 50 is located in the vertical direction of the target nozzle surface. Its horizontal position can be specified by the user according to the inspection requirements (e.g., to ensure complete coverage of the bevel line in weld bevel inspection).

[0045] Starting from beam intersection 50, multiple sound beams are virtually generated according to user-defined beam parameters (such as refraction angle and beam spacing), such as a first sound beam 51 and a second sound beam 52. The refraction angles of the sound beams (such as the first sound beam refraction angle 510, the second sound beam refraction angle 520, etc.) are defined relative to a plane perpendicular to the target surface 5 (perpendicular plane 53). The beam spacing is the angular interval between consecutive beams. The focal plane is the weld surface, and the first sound beam 51 and the second sound beam 52 intersect the focal plane at the first focal point 511 and the second focal point 512, respectively.

[0046] Next, reverse beamline tracing is performed to determine the optimal aperture center. The first acoustic beam 51 and the second acoustic beam 52 originate from their respective first focal points 511 and second focal points 512, passing through the beam intersection point 50. When these beamlines intersect the measured target surface 5, the incident angle of the acoustic beam at the couplant-target interface is calculated using Snell's law, the known sound velocities of the target and wedge, and the refraction angles of the acoustic beams within the target (first acoustic beam refraction angle 510°, second acoustic beam refraction angle 520°).

[0047] The sound beams eventually intersect the effective surface 13 of the probe at specific probe element locations. For example, the first sound beam 51 intersects with the first element 14, and the extension of the second sound beam 52 intersects with the second element 15. Thus, the first element 14 and the second element 15 are respectively determined as the aperture centers for generating the first sound beam 51 and the second sound beam 52 focused at the first focal point 511 and the second focal point 512.

[0048] Once the optimal aperture center is determined for each focal point, the traditional phased array focusing method can be used to calculate the emission delay of all elements within the aperture, which consists of a specific number of elements centered at that aperture center. The combination of these delay parameters constitutes the adaptive focusing rule for that focal point and the current surface profile.

[0049] In another example, when the scanning mode is linear scanning, the beam of the linear scan is configured to enter the test object, reach the desired detection depth, and have multiple detection points; the beam originates from each detection point, traces along a direction parallel to the angle of refraction towards the effective surface 13 of the probe, intersects with the test surface of the geometric profile, and traces back to the element of the probe at a specific incident angle according to Snell's law, which is defined as the center of the aperture. The detailed implementation of step 303 is as follows: multiple parallel beams are virtually generated into the interior of the target nozzle and intersect with the weld surface of the target nozzle to form a focal point; reverse beamline tracing is performed from the focal point, and Snell's law is applied at the interface of the target nozzle surface to trace back to the element of the phased array probe.

[0050] Step 304: Identify the traced element as the aperture center.

[0051] Step 305: Determine the aperture, centered on the aperture center, and composed of a predetermined number of elements in the phased array probe.

[0052] Step 306: Calculate the adaptive delay parameters for all elements within the aperture.

[0053] Step 307: Combine the adaptive delay parameter and the determined scanning mode to form an adaptive focusing rule for each scanning position.

[0054] As shown above, steps 101 to 104 constitute an adaptive focusing method for a phased array ultrasonic testing system. This adaptive focusing method may include the following main steps: a) Apply a set of contour analysis ultrasonic scans; b) Analyze the echo signal data of the scan; c) Define the geometric profile of the test surface based on the echo signal data; d) Based on the geometric profile, define a series of adaptively focused electronic scans, wherein the electronic scans are configured by determining the center of at least one aperture of the phased array probe; e) Apply the electronic scanning to detect the test object using the center of the aperture.

[0055] In (a)-c), the contour analysis scan used is either a linear scan or a sector scan. For example, the contour analysis scan is not limited to using two linear scans; any form of electronic scan (linear scan, sector scan, or a combination thereof) can be used for this purpose. In (d), the electronic scan used is either a sector scan or a linear scan.

[0056] The overall workflow of the above-mentioned method in practical application is as follows: Step 1 (80): Define beam parameters. In the conventional approach, the user usually inputs the parameters, including but not limited to: material sound velocity, delay line parameters (such as sound velocity, height, and five nominal angles between the probe and the target surface), detection scan type (linear or sector), refraction angle (one or more), focusing type and distance, aperture size, beam spacing, etc.

[0057] Step 2 (81): Obtain the contour of the target surface 5. This step is performed by the surface contour analysis module 7 and includes two sub-steps: Sub-step 81a: Perform multiple phased array acquisitions. Based on the aforementioned method (combined with...) Figure 2 Perform at least two (or more) phased array scans with different steering angles (which may be a combination of linear scans and / or sector scans) to obtain the acoustic data required for surface profile analysis.

[0058] Sub-step 81b: Calculate the surface profile. The surface profile analysis module 7 processes the data obtained in sub-step 81a to calculate the complex surface profile distribution of the test target 4.

[0059] Step 3 (82): Calculate the adaptive focusing rule. This step is performed by the adaptive focusing module 8, which calculates the adaptive focusing rule for the current scan position, including the following sub-steps (performed for each beam in the scan): Sub-step 82a: Beam tracing. Tracing the ultrasonic beam path backward from the focal position towards the target surface 5 (workpiece surface), applying Snell's law at the interface of the target surface 5. For a sector scan, all beams must pass through the predetermined beam intersection point 50 (…). Figure 3 ).

[0060] Sub-step 82b: Determine the aperture center. The intersection of the acoustic beamline and the target surface 5 is defined as the aperture center corresponding to the beam.

[0061] Sub-step 82c: Calculate the retardation rule. For an aperture centered at a defined aperture center and composed of a specified number of elements, calculate its focusing retardation rule.

[0062] Step 4 (83): Perform adaptive scanning to acquire data. Using the same phased array probe 11, apply the adaptive focusing rule calculated in step 82 to acquire acoustic data for all beams in the scan.

[0063] Step 5 (84): Storing and displaying data. The acquired acoustic data is stored and typically presented to the user on display unit 9.

[0064] For a given probe position, completing steps 2 (81) to 5 (84) constitutes a complete inspection scan. When scanning the test target 4 (such as a weld), it is usually necessary to move or step the probe to the next inspection position and repeat steps 2 (81) to 5 (84) to analyze the surface profile of the new position, calculate the new adaptive focusing rule, and obtain data.

[0065] It should be noted that the update frequency of surface profile analysis (i.e., the second step (81)) can be adjusted according to the actual situation. For example, when the surface of the test target 4 (such as the weld) is relatively uniform and the changes are not drastic, the execution frequency of surface profile analysis can be reduced. For example, the second step (81) can be executed only once every 2, 5 or 10 scan positions, and the positions in between can use the previously calculated surface profile or be interpolated to improve the detection efficiency.

[0066] For example, the electronic scanning beam definition method described in this application is also applicable to other phased array data acquisition modes, such as Full Matrix Capture (FMC).

[0067] The method of this application includes: establishing a parametric model containing the geometry and material properties of the small-diameter pipe weld; using the surface profile analysis function of phased array linear and sector scanning, employing adaptive focusing technology to generate multiple sound beams using customized apertures to fully cover the small-diameter pipe fillet weld 6; during the inspection process, adaptive focusing is performed based on a real-time sound beam path delay correction model. This application overcomes the problems of sound beam distortion and uneven sensitivity under the complex geometry of small-diameter pipes caused by traditional fixed focusing methods, eliminates detection dead zones, and improves detection accuracy and efficiency.

[0068] Based on the same inventive concept, this application also provides a phased array ultrasonic testing system for small-diameter pipe testing, which implements the phased array ultrasonic testing method for small-diameter pipe testing described above. The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more phased array ultrasonic testing system embodiments for small-diameter pipe testing provided below can be found in the limitations of the phased array ultrasonic testing method for small-diameter pipe testing described above, and will not be repeated here.

[0069] In one exemplary embodiment, such as Figure 4 and Figure 5 As shown, a phased array ultrasonic testing system for small tube inspection is provided, comprising: a phased array probe 1, an acquisition unit 2, a surface profile analysis module 7, an adaptive focusing module 8, and a delay control module 9.

[0070] The phased array probe 1 is set at each preset scanning position. The surface profile analysis module 7 controls the phased array probe 1 to emit ultrasonic signals to the target pipe through the acquisition unit 2 and receives the ultrasonic echo signals generated by the weld of the target pipe. The acquisition unit 2 is used to convert the ultrasonic echo signals into digital ultrasonic shape data. The surface profile analysis module 7 is used to determine the surface profile information of the weld of the target pipe at each scanning position based on the digital ultrasonic shape data.

[0071] The adaptive focusing module 8 is used to determine the adaptive focusing rule for each scanning position based on the surface contour information and parametric digital model of the weld seam of the target pipe at each scanning position; the adaptive focusing rule includes the scanning mode and adaptive delay parameter.

[0072] The delay control module 9 is used to receive the adaptive focusing rule and, according to the adaptive focusing rule at each scanning position, control the phased array probe 1 through the acquisition unit 2 to perform adaptive phased array scanning on the target pipe weld, thereby obtaining the scanning data of the target pipe weld at each scanning position; and obtain the detection image of the target pipe weld based on the scanning data of the target pipe weld at all scanning positions.

[0073] Specifically, a phased array probe 1 is configured to transmit and receive ultrasonic signals. An acquisition unit 2, connected to the phased array probe 1, is used to receive ultrasonic echo electronic signal data. A surface profile module is configured to execute at least one profile analysis routine to assist in generating a set of profile analysis focusing rules, analyze the corresponding echo signal data, and define the geometric profile of the test surface. The surface profile module acquires the geometric profile of the test surface through multiple phased array scans (such as linear or sector scans). An adaptive focusing module 8 is configured to execute at least one adaptive focusing routine to define at least one adaptive focusing electronic scan, which is partially defined by at least one center of at least one aperture of the probe based on the geometric profile. The adaptive focusing module 8 calculates adaptive focusing rules based on the profile data, generating an optimized sound beam through a customized aperture center, so that the sound beam forms a uniform spacing and full coverage within the test target 4.

[0074] As an optional implementation, when the surface profile analysis module 7 controls the phased array probe 1 to transmit ultrasonic signals to the target pipe through the acquisition unit 2, the scanning mode used is linear scanning or sector scanning.

[0075] In this implementation, the surface profile module uses D profile analysis focusing rules to perform a profile analysis routine, corresponding to D parts of the test surface.

[0076] As an alternative implementation, electronic scanning is performed by transmitting and receiving multiple ultrasonic beams once via the at least one aperture. The test object is inspected at A test locations, A electronic scans are performed, and B surface profile analysis routines and C adaptive focusing routines are performed, where B and C are both less than or equal to A.

[0077] As an optional implementation, the surface profile analysis module 7 and the adaptive focusing module 8 constitute an adaptive focusing unit, configured to work in conjunction with the phased array ultrasonic testing system to detect test objects with complex test surfaces.

[0078] like Figure 5As shown, the phased array probe 1 is used to transmit ultrasonic signals to the test target 4 and receive its echo signals. The test target 4 has a target surface 5 and a fillet weld 6. The phased array probe 1 achieves acoustic coupling with the target surface 5 through a relatively thick layer of fluid coupling agent (e.g., water). This coupling method can be achieved by having a thin layer of coupling agent (not shown in the figure) between the phased array probe 1 and the target surface 5. The key feature of this application is the addition of a surface profile analysis module 7 and an adaptive focusing module 8. The surface profile analysis module 7 receives data from the acquisition unit 2 and generates surface profile information of the fillet weld 6 by executing a specific profile analysis program. The adaptive focusing module 8 uses this surface profile information to perform an adaptive focusing process, generate adaptive focusing rules, and instruct the delay control module 9 to scan and detect according to these rules. Exemplarily, the coupling method is not limited to contact coupling; other adaptive coupling methods, such as using a soft, deformable polymer material as the coupling medium, are also compatible with the teachings of this application.

[0079] The acquisition unit 2 is connected to the phased array probe 1 and is used to receive and process the electronic echo signal data returned by the phased array probe 1. The delay control module 9 can be an existing phased array system 3 with basic data processing and display functions.

[0080] In one embodiment, the acquisition unit 2 and the delay control module 9 can serve as the foundation of a portable phased array system 3, while the surface profile analysis module 7 and the adaptive focusing module 8 can be added as new functional modules to this foundation system, or they can be integrated into a new phased array system 3. Both configurations fall within the scope of this application.

[0081] As an optional implementation, the delay control module 9 includes a control unit and an imaging processing unit. The control unit receives the adaptive focusing law and sends it to the transmitting circuit in the acquisition unit 2. The transmitting circuit, based on the transmission delay in the adaptive delay parameters, sequentially excites the wafer of the phased array probe 1 at each scanning step or angle to generate a focused acoustic beam corresponding to the scanning mode and directs it into the target nozzle. The phased array probe 1 receives the echo from the weld of the target nozzle and generates an ultrasonic echo signal. The receiving circuit in the acquisition unit 2 receives the ultrasonic echo signal and applies a receiving delay matching the transmission law. It dynamically focuses the ultrasonic echo signals at different depths, amplifies and performs analog-to-digital conversion on the dynamically focused ultrasonic echo signals to form digital ultrasonic waveform data for each channel. Simultaneously, it summarizes the digital ultrasonic waveform data of each channel into a complete A-scan waveform data. The imaging processing unit processes all A-scan waveform data, synthesizes and generates a two-dimensional or three-dimensional detection image of the weld of the target nozzle.

[0082] The delay control module 9 also includes a display unit. The display unit is used to display the two-dimensional or three-dimensional inspection image of the target pipe weld on the system interface in real time.

[0083] The following is combined Figure 4 and Figure 5 The workflow of the system in this application will be described in detail.

[0084] (a) Surface profile measurement The surface profile analysis module 7 measures the surface profile of the test target 4 acoustically. This is achieved by acquiring data through multiple phased array scans (preferably linear scans) using the phased array probe 1.

[0085] The surface profile analysis module 7 controls the acquisition unit 2 to perform at least two phased array linear scans with different steering angles (i.e., the angle between the sound beam and the workpiece surface) to acquire data. Using multiple beams at different angles for profile analysis is beneficial for more accurately acquiring surface information of complex geometries.

[0086] By analyzing this set of scans (e.g.) Figure 2 The acoustic data obtained from the scan shown can be processed to analyze the contour of the entire target surface 5 reached by the sound beam.

[0087] The acquisition unit 2 receives the raw electronic echo signal (analog signal) from the phased array probe 1 and performs a series of standard signal processing steps on it. The core steps include: ① Signal conditioning: Amplify weak echo signals and may use filters to reduce noise and improve the signal-to-noise ratio.

[0088] ② Analog-to-Digital Conversion (ADC): Converts a conditioned analog signal into a digital signal.

[0089] ③ Data formatting: The digitized signal is organized according to time sequence or channel sequence to form digitized waveform data (usually called A-scan data) that can be read and processed by subsequent modules.

[0090] The "data" output by acquisition unit 2 and transmitted to surface profile analysis module 7 is the digitized ultrasonic waveform data after the above processing. This data completely preserves the time, amplitude, and phase information of the echo signal, providing an accurate input basis for surface profile analysis module 7 to perform algorithm analysis (such as calculating the sound path through the transit time and then inferring the profile).

[0091] After obtaining accurate information about the distribution of the phased array probe 1 relative to the complex surface of the target, the adaptive focusing module 8 can execute the following adaptive focusing rules accordingly.

[0092] (ii) Adaptive Focusing (1) Control process of adaptive focusing module 8 → delay control module 9 → acquisition unit 2 The adaptive focusing module 8 calculates a set of optimized transmit / receive delay parameters (i.e., adaptive focusing rules) based on the geometric model received from the surface profile analysis module 7.

[0093] Subsequently, the delay control module 9 feeds back the calculated new rule to the acquisition unit 2.

[0094] The acquisition unit 2 receives and loads this new set of rules, and immediately uses it to update the delay parameters of the phased array probe 1, so that in the next round of scanning, the sound beam can be dynamically optimized and focused according to the actual detected workpiece state.

[0095] (2) Logic of acquisition unit 2 → delay control module 9 The acquisition unit 2 amplifies and converts the raw ultrasonic echo signal received from the probe into digital A-scan waveform data, and sends it to the delay control module 9.

[0096] (3) Logic of delay control module 9 → acquisition unit 2 The control signal of the delay control module 9 is first sent to the transmitting circuit in the acquisition unit 2, and then the circuit drives the crystal in the phased array probe 1 to emit an ultrasonic beam with a specific waveform and direction according to the new rule, thereby completing an adaptive detection cycle.

[0097] The beneficial effects of this application are as follows: High focusing accuracy: Through adaptive focusing, the influence of the curvature of the small tube on the propagation of the sound beam is effectively compensated, so that the sound beam always maintains good focus in the detection area, eliminating the detection dead zone and improving the detection accuracy.

[0098] Quantitative accuracy: Precise acoustic beam control provides the basis for accurate defect localization and quantitative assessment, reducing the risk of misjudgment and missed judgment.

[0099] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A phased array ultrasonic testing method for small-diameter pipe testing, characterized in that, include: Construct a parametric digital model of the target weld joint; At each preset scanning position of the phased array probe, the surface contour information of the target pipe weld is determined by performing phased array scanning on the target pipe weld at each scanning position. Based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, an adaptive focusing rule is determined for each scanning position; the adaptive focusing rule includes the scanning mode and adaptive delay parameters. At each scanning position, an adaptive phased array scan is performed on the target nozzle weld according to the adaptive focusing rule at each scanning position to obtain the scanning data of the target nozzle weld at each scanning position; Based on the scanning data of the target nozzle weld at all scanning positions, the inspection image of the target nozzle weld is obtained.

2. The phased array ultrasonic testing method for small tube inspection according to claim 1, characterized in that, At each preset scanning position of the phased array probe, the surface contour information of the target nozzle weld is determined by performing phased array scanning on the target nozzle weld at each scanning position, specifically including: At each preset scanning position of the phased array probe, the phased array probe is controlled to perform phased array scanning of the target pipe weld at different turning angles to obtain ultrasonic echo data at each scanning position. Identify and extract valid echo data from the ultrasound echo data at each scanning location; The sound wave propagation path length is determined based on each valid echo data. Based on the sound wave propagation path length, the coordinates of the surface feature points in space corresponding to each valid echo data are calculated through geometric relationships. The coordinates of all the calculated surface feature points in space are arranged in spatial order, and a curve fitting algorithm is used to generate the surface profile curve of the target pipe weld. Determine the geometric parameters in the surface profile curve of the target nozzle weld and use them as the surface profile information of the target nozzle weld at each scanning position.

3. The phased array ultrasonic testing method for small tube testing according to claim 1, characterized in that, Based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, an adaptive focusing rule is determined for each scanning position, specifically including: When the outer wall of the main pipe is perpendicular to the branch pipe in the parametric digital model, the scanning mode is determined to be linear scanning; When the outer wall of the main pipe is not perpendicular to the branch pipe in the parametric digital model, the scanning mode is determined to be sector scanning. Based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, the ultrasonic ray path is traced backward from the focal position to the target nozzle surface, and Snell's law is applied at the interface of the target nozzle surface to trace back to the components of the phased array probe. The traced element is identified as the aperture center; Determine the aperture, centered on the aperture center, and composed of a predetermined number of elements in the phased array probe; Calculate the adaptive delay parameters of all elements within the aperture; The adaptive delay parameter and the determined scanning mode together constitute the adaptive focusing rule for each scanning position.

4. The phased array ultrasonic testing method for small tube inspection according to claim 3, characterized in that, When the scanning mode is fan-shaped scanning, based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, the ultrasonic ray path is traced backward from the focal position to the target nozzle surface. Snell's law is applied at the interface of the target nozzle surface to trace back to the components of the phased array probe, specifically including: A beam intersection is defined on the surface of the target nozzle in the parametric digital model; the beam intersection is located in the vertical direction of the target nozzle surface; Starting from the beam intersection point, multiple sound beams are virtually generated into the interior of the target nozzle and intersect with the weld surface of the target nozzle to form a focal point; Starting from the focal point, reverse acoustic beamline tracing is performed, and Snell's law is applied to the interface of the target receptacle surface to trace back to the elements of the phased array probe.

5. The phased array ultrasonic testing method for small tube inspection according to claim 3, characterized in that, When the scanning mode is linear scanning, based on the surface contour information and parametric digital model of the target nozzle weld at each scanning position, the ultrasonic ray path is traced backward from the focal position to the target nozzle surface. Snell's law is applied at the interface of the target nozzle surface to trace back to the components of the phased array probe, specifically including: Multiple parallel beams are virtually generated inside the target nozzle and intersect with the weld surface of the target nozzle to form a focal point; Starting from the focal point, reverse acoustic beamline tracing is performed, and Snell's law is applied at the interface of the target receptacle surface to trace back to the components of the phased array probe.

6. The phased array ultrasonic testing method for small tube testing according to claim 1, characterized in that, At each scanning position, an adaptive phased array scan is performed on the target nozzle weld according to the adaptive focusing rule at each scanning position to obtain the scanning data of the target nozzle weld at each scanning position, specifically including: Based on the transmission delay in the adaptive delay parameters, the phased array probe's chip is sequentially excited at each scanning step or angle to generate a focused acoustic beam of the corresponding scanning mode and inject it into the target receiver. When receiving echoes from the target weld seam, a receiving delay matching the emission law is applied to dynamically focus echoes at different depths. The echo signals from each channel are combined into a complete A-scan waveform to obtain the scan data of the target nozzle weld at each scan position.

7. A phased array ultrasonic testing system for small tube inspection, characterized in that, include: Phased array probe, acquisition unit, surface profile analysis module, adaptive focusing module, and delay control module; The phased array probe is set at each preset scanning position. The surface profile analysis module controls the phased array probe to emit ultrasonic signals to the target pipe through the acquisition unit and receives the ultrasonic echo signals generated by the weld of the target pipe. The acquisition unit is used to convert the ultrasonic echo signals into digital ultrasonic shape data. The surface profile analysis module is used to determine the surface profile information of the weld of the target pipe at each scanning position based on the digital ultrasonic shape data. The adaptive focusing module is used to determine the adaptive focusing rule for each scanning position based on the surface contour information and parametric digital model of the weld seam of the target pipe at each scanning position; the adaptive focusing rule includes the scanning mode and adaptive delay parameter; The delay control module is used to receive the adaptive focusing rule and, according to the adaptive focusing rule at each scanning position, control the phased array probe through the acquisition unit to perform adaptive phased array scanning on the target nozzle weld, thereby obtaining the scanning data of the target nozzle weld at each scanning position; and obtain the detection image of the target nozzle weld based on the scanning data of the target nozzle weld at all scanning positions.

8. The phased array ultrasonic testing system for small tube inspection according to claim 7, characterized in that, When the surface profile analysis module controls the phased array probe to transmit ultrasonic signals to the target pipe through the acquisition unit, the scanning mode used is either linear scanning or sector scanning.

9. The phased array ultrasonic testing system for small tube inspection according to claim 7, characterized in that, The delay control module includes: a control unit and an imaging processing unit; The control unit is used to receive the adaptive focusing law and send it to the transmitting circuit in the acquisition unit; the transmitting circuit, according to the transmission delay in the adaptive delay parameter, sequentially excites the phased array probe's crystal at each scanning step or angle to generate a focused sound beam of the corresponding shape of the scanning mode and shoots it into the target connector. The phased array probe receives the echo from the weld seam of the target nozzle, generating an ultrasonic echo signal. The receiving circuit in the acquisition unit receives the ultrasonic echo signal and applies a receiving delay that matches the emission law. It dynamically focuses the ultrasonic echo signals at different depths, amplifies and converts the dynamically focused ultrasonic echo signals into digital ultrasonic waveform data for each channel, and simultaneously summarizes the digital ultrasonic waveform data from each channel into a complete A-scan waveform data. The imaging processing unit processes all the A-scan waveform data, synthesizes and generates a two-dimensional or three-dimensional inspection image of the weld seam of the target nozzle.

10. The phased array ultrasonic testing system for small tube inspection according to claim 9, characterized in that, The delay control module further includes: a display unit; The display unit is used to display two-dimensional or three-dimensional inspection images of the target pipe weld on the system interface in real time.

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