Welded joint ultrasonic phased array automatic detection device and method

Abstract

The invention provides a welded joint ultrasonic phased array automatic detection device and method, and the method comprises the steps: selecting a longitudinal wave mode or a transverse wave mode on an interface of a control computer, inputting sample parameters, calculating acoustic beam excitation delay, and setting the acoustic beam excitation delay in an ultrasonic transmitting / receiving module; a mechanical scanning mechanism is driven according to the set parameters, so that a phased array probe moves on the surface of the welding joint according to a preset path; ultrasonic waves are sent to the welding joint according to the acoustic beam excitation delay, echo signals are received, the echo signals are processed to obtain scanning signals, and the scanning signals are uploaded to the control computer; processing the scanning signal to generate a scanning image, segmenting and identifying the scanning image, and extracting incomplete fusion and incomplete penetration defect areas in the scanning image; and performing three-dimensional visual imaging on the defect area and analyzing a characteristic curve extracted from the primary echo amplitude of the echo signal to obtain three-dimensional data of the defect area and storing the three-dimensional data.

Description

Technical Field

[0001] The invention relates to the technical field of nondestructive testing of metal welding, and in particular to an ultrasonic phased array automatic testing device and a monitoring method for welding joints. Background Art

[0002] Welded joints are a common connection method in modern industry. Currently, a large number of metal steel plate connections are completed by manual MIG welding or TIG welding. Since welding is mainly done manually, the welding quality is closely related to the operator's technical level. It is very easy to produce unstable welding parameters due to improper operation and poor weld formation caused by insufficient heat input, resulting in welding defects such as tungsten inclusions, pores, lack of fusion and incomplete penetration, which greatly increases the probability of accidents caused by failure of welded joints during service.

[0003] Therefore, for the quality of stainless steel welded joints, it is necessary not only to ensure the technical level standards of welders and strictly implement welding procedures at the source, but also to conduct post-weld inspection and evaluation of the quality of welded joints, especially the internal quality, so as to ensure the reliability of the shelf structure.

[0004] At present, the quality assessment of welded joints mainly adopts destructive testing and non-destructive testing methods. Destructive testing requires destructive processing of welded parts and preparation of samples for metallographic analysis of welded joints, or performance tests such as tensile, bending, impact and fatigue.

[0005] This not only causes a large amount of material waste, but also makes it impossible to test the performance of welded joints in service. Nondestructive testing mainly uses radiographic testing (RT), ultrasonic testing (UT), magnetic particle testing (MT), magnetic memory testing (MMT), and penetration testing (PT) to test the quality of welded parts. Among them, ultrasonic testing is a conventional A-scan test on the surface of the workpiece by a worker holding an ultrasonic probe. The judgment of the defect signal characteristics of the plug welding joint depends entirely on the personal experience of the inspector, which is prone to false detection and missed detection of defects. Compared with conventional ultrasonic testing methods, phased array ultrasonic testing technology is based on the Huygens-Fresnel principle and the interference and superposition theory of waves. It uses modern electronic and computer technology to control each array element in the array ultrasonic transducer, and transmits and receives ultrasonic waves according to the pre-set delay law, thereby dynamically controlling the deflection and focusing of the ultrasonic beam within a certain spatial range, realizing an ultrasonic testing method of electronic focusing and scanning. Phased array ultrasound has the advantages of high sensitivity, wide detection range, and the ability to quickly form intuitive detection images. When ultrasonic testing of welded joints is performed, both conventional ultrasound and phased array ultrasound are based on the reflection, refraction, transmission and attenuation characteristics of sound waves during propagation inside the material.

[0006] Therefore, how to efficiently and accurately detect and monitor the quality of welded joints has become an important issue. Summary of the invention

[0007] In a first aspect of the present disclosure, there is provided an ultrasonic phased array automatic detection device for welded joints, comprising:

[0008] A control computer is used for human-computer interaction, controlling the phased array ultrasonic transmitting / receiving module, receiving feedback signals, and communicating with the motion control module;

[0009] A phased array ultrasonic transmitting / receiving module communicates with the control computer and is used to transmit and receive ultrasonic signals, perform parallel signal processing and data storage, and upload detection data to the control computer;

[0010] Phased array probe, including 32-element linear array, element spacing is less than or equal to 0.3mm, and center frequency is greater than or equal to 10MHz;

[0011] A motion control module, comprising a stepper motor control card and a stepper motor driver, wherein the stepper motor control card is connected to the control computer via a USB interface, and the stepper motor driver is used to drive the stepper motor to realize the movement of the detection device;

[0012] A mechanical scanning mechanism, used for supporting and moving the phased array probe to perform mechanical scanning;

[0013] The data transmission interface is used to implement TCP / IP protocol communication between the control computer and the phased array ultrasonic transmitting / receiving module.

[0014] In combination with the first aspect, the control computer runs human-computer interaction software, including the following modules:

[0015] Ultrasonic parameter and mechanical scanning parameter setting module, used to input sample thickness, sound velocity, focal depth, and automatically calculate the delay parameters of acoustic beam excitation;

[0016] Ultrasonic excitation and reception module, used to control the excitation and reception of ultrasonic signals;

[0017] A motion control module, used to control the mechanical scanning mechanism according to a preset scanning area, step angle and step speed;

[0018] A signal processing and image display module, used for processing ultrasonic echo signals and generating scanned images;

[0019] The data storage module is used to store and manage detection data.

[0020] In combination with the first aspect, the detection mode of the probe includes a longitudinal wave mode and a shear wave mode.

[0021] The longitudinal wave detection mode is coupled to the workpiece by direct coupling or rectangular wedges, and is used to detect defects parallel to the workpiece surface;

[0022] The shear wave detection mode is coupled to the workpiece through wedges with different inclination angles and is used to detect defects that are perpendicular or inclined to the surface of the workpiece.

[0023] A second aspect of the present disclosure provides a method for automatic detection of welded joints by ultrasonic phased array, comprising:

[0024] Select longitudinal wave mode or transverse wave mode on the control computer interface, input the sample plate thickness, sound velocity and focal depth parameters, calculate the acoustic beam excitation delay and set it in the ultrasonic transmitting / receiving module;

[0025] The scanning area, step angle and step speed are set on the control computer, and the motion control module drives the mechanical scanning mechanism according to the set parameters, so that the phased array probe moves along a preset path on the surface of the weld joint;

[0026] The phased array ultrasonic transmitting / receiving module transmits ultrasonic waves to the welding joint according to the acoustic beam excitation delay and receives echo signals, processes the echo signals to obtain scanning signals and uploads them to the control computer;

[0027] The control computer receives the scanning signal, generates a scanning image after processing, and segments and identifies the scanning image, and extracts the defective areas of incomplete fusion and incomplete penetration in the scanning image;

[0028] The control computer performs three-dimensional visualization imaging on the defect area and analyzes a characteristic curve extracted from a primary echo amplitude of the echo signal to obtain and store three-dimensional data of the defect area.

[0029] In combination with the second aspect, the method includes, in a longitudinal wave mode, using direct coupling when detecting a workpiece with a thickness greater than a first preset thickness or a defect greater than a first preset depth, and using rectangular wedge coupling when detecting a workpiece with a thickness less than the first preset thickness or a defect less than the first preset depth.

[0030] In combination with the second aspect, the method includes configuring wedges with different inclination angles in a shear wave mode to allow ultrasonic waves to be obliquely incident on the surface of the weld joint at a set incident angle, so as to detect defects that are perpendicular to the workpiece surface or distributed at an acute or obtuse angle.

[0031] In combination with the second aspect, the method further includes separating the workpiece surface echo signal from the defect echo signal and suppressing the background noise when the distance between the middle layers of the weld joint and the detection surface is less than 1.2 mm.

[0032] In combination with the second aspect, the method further includes decomposing the echo signal to obtain signal components in different frequency bands, selecting the signal components according to noise distribution characteristics, and reconstructing them to obtain the defect echo signal.

[0033] According to a third aspect of the present disclosure, an electronic device is provided, including:

[0034] one or more processors;

[0035] A storage unit is used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors can implement any of the above-mentioned ultrasonic phased array automatic detection devices and methods for welding joints.

[0036] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it can implement any of the above-mentioned ultrasonic phased array automatic detection devices and methods for welded joints.

[0037] Beneficial effects: The ultrasonic phased array automatic detection device and method for welded joints provided by the present invention realizes efficient and accurate automatic detection of welded joints by combining phased array ultrasonic technology, motion control system and advanced signal processing algorithm. The device enables the phased array ultrasonic probe to accurately scan the surface of the welded joint through the automated control system, avoiding errors in manual operation and improving detection efficiency. The high-resolution phased array probe can capture tiny defects and ensure high-sensitivity detection. By decomposing and reconstructing the echo signal, the noise is effectively suppressed and the signal is optimized, which significantly improves the accuracy of defect identification. The three-dimensional visualization imaging technology intuitively displays the defect area and performs accurate analysis, supporting real-time feedback and subsequent processing. In the method, the flexible switching of longitudinal and shear wave modes and the application of different coupling modes enable the device to efficiently detect various types of defects without being restricted by the workpiece morphology. On the whole, the device and method disclosed in the present invention improve the automation, accuracy and reliability of welded joint detection, reduce manual errors, and have important application value in welding quality control. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the ultrasonic phased array detection principle of an embodiment of the present disclosure;

[0039] Figure 2 It is a structural schematic diagram of an ultrasonic phased array automatic detection device for welded joints according to an embodiment of the present disclosure;

[0040] Figure 3 A schematic diagram of a process of an ultrasonic phased array automatic detection method for welded joints according to an embodiment of the present disclosure;

[0041] Figure 4It is a schematic diagram of the structure of an electronic device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the embodiments of the present disclosure.

[0043] The terms used in the disclosed embodiments are only for the purpose of describing specific embodiments and are not intended to limit the disclosed embodiments. The singular forms of "a", "said" and "the" used in the disclosed embodiments and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0044] It should be understood that although the terms first, second, third, etc. may be used to describe various information in the disclosed embodiments, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the disclosed embodiments, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0045] like Figure 1 FIG. 1 is a schematic diagram of the ultrasonic phased array detection principle of an embodiment of the present disclosure, specifically:

[0046] By controlling the incident angle and propagation mode of ultrasonic waves, comprehensive detection of internal defects of the workpiece can be achieved. The ultrasonic probe 110 transmits the sound wave to the workpiece at a certain angle through the wedge 120. The 35° and 70° marked in the figure are commonly used incident angles. The 35° incident angle is mainly used to generate longitudinal waves, which are suitable for detecting defects parallel to the surface of the workpiece, such as delamination or inclusions. The 70° incident angle will generate shear waves. The propagation characteristics of shear waves make it more suitable for detecting defects perpendicular to the beam direction, such as lack of fusion or cracks in welds.

[0047] The propagation path of ultrasonic waves in the workpiece changes due to refraction and reflection. The sound beam ranges marked in the figure (such as "a" and "a-") illustrate the area covered by the ultrasonic wave, and the key point "X" represents the reflection focus of the sound wave on the bottom surface of the workpiece. By analyzing the path and time of the reflected wave, the position and shape of the defect can be accurately located. This multiple reflection and path analysis can cover the bottom surface and complex internal areas of the workpiece to avoid omissions.

[0048] Ultrasonic testing at different angles can identify defects at different depths and directions of the workpiece. By adjusting the coverage and incident angle of the sound beam, accurate non-destructive detection can be performed on workpieces with complex structures, especially weld areas. This method is applicable to various industrial scenarios and ensures the comprehensiveness and reliability of detection.

[0049] Refer to the following Figure 2-Figure 4 Give specific instructions.

[0050] like Figure 2 FIG. 1 is a schematic diagram of a structure of an ultrasonic phased array automatic detection device for welded joints according to an embodiment of the present disclosure, comprising:

[0051] A control computer 210 is used for human-computer interaction, controlling the phased array ultrasonic transmitting / receiving module, receiving feedback signals, and communicating with the motion control module;

[0052] A phased array ultrasonic transmitting / receiving module 220 communicates with the control computer, is used to transmit and receive ultrasonic signals, perform parallel signal processing and data storage, and upload detection data to the control computer;

[0053] The phased array probe 230 includes a 32-element linear array, an element spacing of less than or equal to 0.3 mm, and a center frequency of greater than or equal to 10 MHz;

[0054] The motion control module 240 includes a stepper motor control card and a stepper motor driver, wherein the stepper motor control card is connected to the control computer via a USB interface, and the stepper motor driver is used to drive the stepper motor to realize the movement of the detection device;

[0055] A mechanical scanning mechanism 250, used to support and move the phased array probe to perform mechanical scanning;

[0056] The data transmission interface 260 is used to implement TCP / IP protocol communication between the control computer and the phased array ultrasonic transmitting / receiving module.

[0057] The control computer 210 serves as the core control unit of the device and undertakes the following functions:

[0058] Human-computer interaction: Provides a user interface for setting detection parameters (such as ultrasonic signal frequency, focal depth, scanning path, etc.) and displays the detection results in real time.

[0059] Control function: Control the signal excitation and acquisition of the phased array ultrasonic transmitting / receiving module, as well as the scanning path and speed of the motion control module through instructions.

[0060] Data reception and processing: After acquiring echo data from the phased array ultrasonic transmitting / receiving module, data analysis, defect detection and result presentation are performed.

[0061] The phased array ultrasonic transmitting / receiving module 220 is the core processing unit of the ultrasonic signal, and its functions include:

[0062] Transmission and reception of ultrasonic signals: The phased array probe is controlled to transmit ultrasonic waves according to the set parameters, and the echo signals reflected by the workpiece are received.

[0063] Parallel signal processing: Synchronous processing of multi-channel signals is achieved through high-performance processing units to improve detection efficiency and accuracy.

[0064] Data storage and transmission: The detected raw data and processing results are stored and sent to the control computer through the data transmission interface.

[0065] The phased array probe 230 adopts a 32-element linear array design, with an element spacing of no more than 0.3 mm and a center frequency of no less than 10 MHz, ensuring the following performance:

[0066] High-resolution detection: Small element spacing and high frequency ensure high sensitivity and spatial resolution for tiny defects.

[0067] Multi-mode detection: Supports longitudinal wave mode and shear wave mode, and can flexibly adapt to different types of welding defects (such as lack of fusion and lack of penetration).

[0068] The motion control module 240 achieves precise movement of the probe by:

[0069] Stepper motor control card: communicates with the control computer through the USB interface and generates motion instructions according to the preset scanning path and speed.

[0070] Stepper motor driver: executes the instructions of the stepper motor control card, drives the mechanical structure to move the probe, and achieves high-precision positioning.

[0071] The mechanical scanning mechanism 250 is used to support and guide the phased array probe to move along a preset path on the surface of the workpiece. The design highlights include:

[0072] High stability: Ensure that the probe remains stable during scanning to avoid loss of detection accuracy due to vibration or displacement.

[0073] Flexible adjustment: Supports adaptive adjustment of different workpiece sizes and shapes.

[0074] Data transmission interface 260 realizes efficient and stable data communication through TCP / IP protocol:

[0075] Two-way communication: supports command transmission and data feedback between the control computer and the phased array ultrasonic transmitting / receiving module.

[0076] High-speed transmission: It meets the demand for large-scale transmission of ultrasonic signals and ensures real-time transmission and processing of detection data.

[0077] Beneficial effects: The design of the device takes into account the collaborative work of the hardware modules and the functional expansion of the software modules, ensuring the detection accuracy and ease of operation. The device is suitable for non-destructive detection of internal defects in welded joints, especially for deep-buried defects, tiny cracks, and lack of fusion. By replacing the probe and upgrading the algorithm module, it can adapt to other types of workpieces or defect detection needs, improving versatility and economic benefits.

[0078] Figure 3 The present invention is a schematic diagram of a process of an ultrasonic phased array automatic detection method for welded joints according to an embodiment of the present invention, comprising:

[0079] S301: Selecting the longitudinal wave mode or the transverse wave mode on the interface of the control computer, inputting the sample plate thickness, sound velocity and focal depth parameters, calculating the acoustic beam excitation delay and setting it in the ultrasonic transmitting / receiving module;

[0080] S302: Setting the scanning area, step angle and step speed on the control computer, and the motion control module drives the mechanical scanning mechanism according to the set parameters, so that the phased array probe moves along a preset path on the surface of the weld joint;

[0081] S303: the phased array ultrasonic transmitting / receiving module transmits ultrasonic waves to the welding joint according to the acoustic beam excitation delay and receives echo signals, processes the echo signals to obtain scanning signals and uploads them to the control computer;

[0082] S304: Processing the scanning signal to generate a scanning image and segmenting and identifying the scanning image to extract defective areas of incomplete fusion and incomplete penetration in the scanning image;

[0083] S305: Perform three-dimensional visualization imaging on the defect area and analyze the characteristic curve extracted from the first echo amplitude of the echo signal to obtain and store three-dimensional data of the defect area. Specifically,

[0084] S301: Select the detection mode, input the detection parameters and set the acoustic beam excitation delay.

[0085] The user selects the detection mode through the operation interface of the control computer:

[0086] Longitudinal wave mode: Suitable for detecting defects parallel to the surface of the weld joint, such as cracks or lack of fusion.

[0087] Shear wave mode: Suitable for detecting vertical or inclined defects on the surface of welded joints, such as incomplete penetration.

[0088] Enter the test parameters of the sample, including:

[0089] Plate thickness: The thickness of the workpiece, used to calculate the ultrasonic propagation time.

[0090] Speed ​​of sound: The speed at which ultrasonic waves propagate in a material. Different materials (such as steel and stainless steel) have different speeds of sound.

[0091] Depth of focus: The depth of the ultrasound focus point, which is used to determine the detection accuracy and coverage of the probe.

[0092] The system automatically calculates the acoustic beam excitation delay based on the input parameters, and sets it to each array element through the phased array ultrasonic transmitting / receiving module to achieve precise focusing of the acoustic beam.

[0093] S302: Set scanning parameters and drive the probe to move.

[0094] Enter and set scan parameters on the controlling computer:

[0095] Scanning area: Defines the inspection area that the probe needs to cover, usually determined by the shape and size of the weld joint.

[0096] Step Angle: The angle or linear step length of each probe movement, used to improve coverage and detection accuracy.

[0097] Stepping speed: The speed at which the probe moves across the workpiece surface needs to balance efficiency and signal acquisition accuracy.

[0098] The motion control module drives the mechanical scanning mechanism to move the probe according to the above parameters to ensure that it moves evenly along the surface of the weld joint according to the preset path to avoid missed inspections or repeated coverage.

[0099] S303: Ultrasonic signal transmission, reception and processing.

[0100] The phased array ultrasonic transmitting / receiving module transmits ultrasonic waves to the welding joint through the probe according to the set acoustic beam excitation delay.

[0101] After the probe receives the reflected echo signal, the module processes the signal:

[0102] Denoising and amplification: Preliminary filtering of background noise and enhancement of effective signals.

[0103] Multi-channel parallel processing: synchronously process the signals of all array elements to improve signal quality and detection efficiency.

[0104] The processed scan signal is uploaded to the control computer for subsequent analysis.

[0105] S304: Generate a scan image and identify defects.

[0106] The control computer further processes the scan signal:

[0107] Generate scanning images: intuitively display the internal structure of the workpiece and the echo intensity distribution in the form of A-scan, B-scan or C-scan.

[0108] Image segmentation and recognition: Use algorithms to segment scanned images, extract defective areas such as lack of fusion and lack of penetration, and eliminate interference from normal areas.

[0109] After identifying the defective area, the system automatically marks its location and shape, laying the foundation for subsequent analysis.

[0110] S305: Defect 3D visualization and data storage.

[0111] 3D visualization imaging: Based on multi-angle scanning data, a 3D model of the defect area is reconstructed, allowing inspectors to intuitively observe the shape, depth and distribution of the defects.

[0112] Characteristic curve analysis: Extract the amplitude of an echo from the echo signal, generate a characteristic curve, and analyze the nature of the defect (such as size and type).

[0113] Data storage: The generated 3D data, scanned images and feature analysis results are stored in the database for subsequent traceability and quality assessment.

[0114] Beneficial effects: Combining longitudinal wave and shear wave detection modes, it can identify various defects in welding joints and adapt to different working conditions. The mechanical scanning mechanism is linked with the control computer to achieve high-efficiency detection and real-time result feedback. Three-dimensional imaging enhances the intuitiveness of detection and facilitates analysis and decision-making.

[0115] Furthermore, the method includes using direct coupling when detecting workpieces with a thickness greater than a first preset thickness or defects greater than a first preset depth in a longitudinal wave mode, and using rectangular wedge coupling when detecting workpieces with a thickness less than the first preset thickness or defects less than the first preset depth.

[0116] Specific application scenarios of direct coupling:

[0117] When the thickness of the workpiece to be detected is greater than a first preset thickness (such as 10 mm or other set values) or when the depth of the defect to be detected is greater than a first preset depth (such as 3 mm or other set values), the ultrasonic probe is directly coupled to the surface of the workpiece.

[0118] Since direct coupling reduces the loss of acoustic energy, the signal strength and signal-to-noise ratio are high, which is suitable for defect detection in deeper parts or thicker workpieces. The coupling loss is low and the signal quality is good. The operation is simple and suitable for rapid detection of workpieces of conventional thickness.

[0119] Application scenarios of rectangular wedge coupling: When the thickness of the workpiece to be tested is less than the first preset thickness, such as thin plates or pipe walls (<10mm), direct coupling may cause multiple reflections of the sound wave to interfere with the signal. When the depth of the defect to be tested is greater than the first preset depth, direct coupling may cause blind spots or missed detection.

[0120] Implementation method: Add a rectangular wedge between the probe and the workpiece. The wedge can effectively reduce interference and improve detection sensitivity by adjusting the angle and sound wave path.

[0121] The rectangular wedge material needs to match the acoustic velocity of the workpiece to reduce energy loss caused by acoustic impedance mismatch.

[0122] Advantages: Precise focusing: The wedge adjusts the direction of sound wave propagation to improve the detection accuracy of shallow or thin workpiece defects. Strong adaptability: Avoids coupling difficulties caused by differences in workpiece thickness or shape.

[0123] Switching and optimization of detection conditions: The control computer automatically determines and switches the coupling mode according to the input workpiece parameters (such as thickness, defect depth). Users can also manually select direct coupling or rectangular wedge coupling on the interface to cope with special detection scenarios.

[0124] Parameter optimization: For thin workpieces or welding joints with irregular surfaces, the wedge angle and coupling material need to be optimized when coupling with rectangular wedges to reduce acoustic wave losses.

[0125] For thick workpieces or deep defects, the direct coupling method can enhance the detection effect by adjusting the probe pressure and the thickness of the coupling medium.

[0126] Beneficial effects: Flexible adaptation to various working conditions: Through the selection and optimization of coupling methods, it can effectively cover the detection needs of thick plates, thin plates and defects of different depths. Reduce signal interference: The use of rectangular wedges can significantly reduce the interference of multiple reflections in thin plate detection and improve the detection signal-to-noise ratio.

[0127] Improve defect resolution: The direct coupling method performs well in deep defect detection, while the wedge coupling method has advantages in shallow defect and thin workpiece detection.

[0128] Scope of application, direct coupling: suitable for defect detection of conventional welded joints, especially widely used in thick plate workpieces such as heavy machinery and bridges.

[0129] Rectangular wedge coupling: suitable for thin-walled structures (such as aerospace components, thin-walled pipes) and scenarios with higher requirements for surface and shallow defects.

[0130] Furthermore, the method includes configuring wedges with different inclination angles in a shear wave mode to allow ultrasonic waves to be incident obliquely on the surface of the weld joint at a set incident angle, so as to detect defects that are perpendicular to the workpiece surface or distributed at an acute or obtuse angle.

[0131] Specifically, vertically distributed defects: such as defects such as lack of fusion and cracks in welded joints that develop along the depth of the weld. Sharp or obtuse angle distributed defects: such as inclined cracks caused by complex geometric shapes or special welding processes.

[0132] Wedge function: convert the longitudinal wave emitted by the probe into a shear wave, so that the shear wave enters the weld joint at a set incident angle (non-vertical). Adjust the sound wave path, optimize the sound energy focus in the defect area, and improve the detection sensitivity.

[0133] Inclination angle selection: The inclination angle depends on the incident angle of the sound wave and the critical angle of the workpiece material, ensuring that the shear wave propagates within a specific angle range.

[0134] The commonly used inclination angle range is 30° to 70°. Different inclination angles correspond to defect detection at different depths and directions:

[0135] Small inclination angle (30°-45°): suitable for detecting shallow or vertically distributed defects.

[0136] Large inclination angle (60°-70°): suitable for detecting deep or acute / obtuse angle inclined defects.

[0137] Wedge installation: According to the detection requirements, install the wedge with a specific inclination angle under the phased array probe, and ensure that the bottom surface of the wedge is in close contact with the surface of the workpiece.

[0138] Beam adjustment: The control computer calculates the ultrasonic delay law based on the input parameters (such as workpiece material, sound speed, defect type) and sets it in the ultrasonic transmitting / receiving module. The direction of the sound beam is adjusted so that the transverse wave is incident on the surface of the weld joint at an inclined angle and passes through the potential defect area.

[0139] Defect echo signal processing: The echo signal is received by the phased array probe and uploaded to the control computer. The signal processing module denoises, segments and identifies the echo data to extract the characteristics of the defect area. Through the reflection and diffraction characteristics of oblique incident shear waves, defects with complex geometric distribution can be accurately identified.

[0140] The shear wave mode effectively avoids the blind spots that may be caused by the longitudinal wave mode in detecting non-parallel defects or oblique cracks.

[0141] Furthermore, the method also includes separating the workpiece surface echo signal from the defect echo signal and suppressing the background noise when the distance between the middle layers of the weld joint and the detection surface is less than 1.2 mm.

[0142] Specifically, a high-resolution phased array ultrasonic probe is used to collect ultrasonic echo signals of the welded joint, and the echo signals are recorded with high precision in the time domain.

[0143] By calculating the propagation time of the defect signal (based on the known sound speed and distance), the workpiece surface echo signal is separated from the defect echo signal.

[0144] The defect signal is extracted from the received composite signal by utilizing the delay characteristics of the ultrasonic signal. The surface echo signal is usually more concentrated in frequency, while the defect echo signal has a wider frequency band. The wide-band signal is isolated by a bandpass filter to highlight the defect characteristics.

[0145] By utilizing the beam focusing capability of the phased array probe, the ultrasonic emission angle is adjusted so that the key area of ​​signal reception is concentrated on the potential defect area, thereby reducing surface signal interference.

[0146] Noise source analysis: Random noise from workpiece surface roughness, probe electronic system and environment may mask defect signals.

[0147] Noise reduction strategy: Wavelet transform denoising, decomposing the echo signal into multi-scale wavelet coefficients, suppressing high-frequency noise in small scales, and then reconstructing the signal to restore clear defect features.

[0148] Adaptive filtering: Dynamically adjust the filter parameters to match the characteristic frequency of the defect signal and remove background noise to the maximum extent.

[0149] Noise threshold suppression: Set the background noise threshold and directly filter the signal components below the threshold to improve the signal-to-noise ratio.

[0150] Based on the signal characteristics detected in real time, the separation and noise reduction parameters are dynamically adjusted to adapt to weld joints with different thicknesses and defect distributions.

[0151] The separated defect echo signals are visualized in three dimensions and combined with the amplitude characteristics of the defects to clearly display the defect location, shape and size.

[0152] In the case where a single echo signal is not sufficient to separate clearly, the defect identification information can be supplemented by analyzing the reflection behavior of multiple echoes.

[0153] Beneficial effect: It can effectively separate the unfused defect signals between the layers less than 1.2mm from the detection surface and avoid surface signal interference.

[0154] Through the combination of multiple noise reduction technologies, the real characteristics of the defect signal can be restored to the maximum extent. It is suitable for defect detection needs of various materials (such as steel, aluminum, titanium, etc.) and different welding processes.

[0155] Through the above method, not only the existence of the lack of fusion defect between the layers can be accurately identified, but also the signal characteristics can be enhanced, and the detection reliability of the welding joint and the credibility of the results can be improved.

[0156] In the detection of welded joints, the lack of fusion defects between the middle layers are close to the detection surface (less than 1.2mm), which will cause interference and overlap between the defect echo signal and the workpiece surface echo signal. In order to improve the sensitivity and accuracy of detection, this method uses signal separation and background noise suppression technology to accurately identify the defect area. The specific process is as follows:

[0157] Characteristics of the mid-layer unfused defect: The defect is located in the middle layer of the weld joint and is close to the detection surface (less than 1.2 mm), which is easily confused with the surface echo signal.

[0158] Signal characteristics: The surface echo signal has high intensity and stability, but lacks reflection characteristics. The defect echo signal is weaker, but contains key defect characteristics (such as amplitude attenuation and phase change).

[0159] Signal separation method:

[0160] Signal acquisition: The phased array probe is used to receive ultrasonic echo signals with high resolution and record the reflected signals with fine time resolution.

[0161] Time domain separation: The signal is divided on the time axis according to the difference in propagation time between the workpiece surface echo and the defect echo.

[0162] Digital filtering technology is used to enhance the detail features of the defect echo signal and suppress the main wave interference of the surface echo signal.

[0163] Frequency domain separation: Analyze the spectral characteristics of the signal. The main frequency of the surface echo signal is relatively concentrated, while the defect echo signal presents a broadband distribution due to its structural characteristics.

[0164] A bandpass filter is applied to extract only the broadband characteristic signal to isolate the defect echo signal.

[0165] Spatial separation: Use phased array technology to adjust the beam angle so that the ultrasound can focus on the defect area at multiple angles.

[0166] The spatial distribution characteristics of surface signals and defect signals are separated by beamforming technology.

[0167] Background noise suppression:

[0168] Noise sources: scattering noise caused by the surface roughness of the workpiece, thermal noise of electronic devices in the phased array system and environmental noise.

[0169] Inhibition methods:

[0170] Wavelet denoising: Decompose the echo signal into wavelet coefficients of different scales, identify and remove low-amplitude high-frequency noise components, and then reconstruct the signal to retain the defect characteristics.

[0171] Adaptive filtering: Dynamically adjust filter parameters through algorithms to suppress background noise in real time while enhancing defect echo signals.

[0172] Noise threshold detection: Set the threshold of background noise intensity. Signal components below the threshold are directly filtered to ensure a high signal-to-noise ratio of the detection signal.

[0173] The parameters of the separation and suppression algorithms are dynamically adjusted according to the actual workpiece thickness and defect distribution.

[0174] Three-dimensional visualization: Perform three-dimensional imaging on the defect data after signal separation, and combine the echo amplitude characteristics to clarify the spatial distribution and shape of the defects.

[0175] Result verification: The separated signal is compared with the detection standard and the defect nature is further confirmed through pattern recognition algorithm.

[0176] Through the above method, when the distance between the middle layer unfused defects and the detection surface is less than 1.2mm, high-sensitivity separation of the defect area and effective suppression of background noise can be achieved, thereby ensuring the reliability and accuracy of the detection results.

[0177] Furthermore, the method also includes decomposing the echo signal to obtain signal components in different frequency bands, selecting the signal components according to noise distribution characteristics, and reconstructing them to obtain the defect echo signal.

[0178] The echo signal contains components with different frequency and time domain characteristics, usually including high-frequency signals caused by defects and low-frequency noise signals caused by surface roughness, probe noise, etc. In order to effectively distinguish these signals, this method first decomposes the echo signal:

[0179] Wavelet transform is a method that can perform multi-resolution analysis on signals. By decomposing the echo signal into wavelet coefficients of different frequency bands, the frequency domain components of the signal at different time scales are obtained. Wavelet transform can process the time domain and frequency domain characteristics of the signal at the same time, and is suitable for processing signals containing sudden changes or instantaneous characteristics.

[0180] After signal decomposition, signal components in multiple frequency bands are obtained. Signal components in different frequency bands may correspond to different types of noise or defect echoes. The specific steps are as follows:

[0181] Noise Analysis:

[0182] Low-frequency noise: caused by the probe electronic system, environmental interference or reflection from the workpiece surface, usually appears as a low frequency and is relatively stable.

[0183] High-frequency noise: It may be caused by surface roughness, bubbles, or tiny vibrations generated during the welding process. It is usually a random signal with a higher frequency component.

[0184] By analyzing the decomposed signals of each frequency band, it is determined which frequency bands contain noise components and which frequency bands contain defect echo information.

[0185] According to the noise analysis results, select the appropriate frequency band for further processing:

[0186] Remove noise frequency band: Filter out noise frequency band, especially low-frequency noise and high-frequency noise components with too wide a frequency band.

[0187] Keep defect echo frequency band: Keep the frequency band containing defect information, especially the defect echo signal is usually concentrated in a specific frequency range.

[0188] Frequency feature extraction: Extract features from the selected frequency band, including amplitude, frequency, phase and other parameters. These features can be used for further signal analysis to help accurately locate defects.

[0189] Signal reconstruction and defect echo extraction: After signal decomposition and selection of appropriate frequency bands, the next step is to restore the noise-removed signal to a signal close to the real defect echo through reconstruction.

[0190] Signal reconstruction: Use the signal components of the selected frequency band and combine the signal reconstruction algorithm (such as inverse wavelet transform,) to reconstruct the decomposed signal. Through these transformations, the defect echo signal can be recovered from the multi-scale and multi-band information.

[0191] The reconstructed signal is purer and the noise interference is greatly reduced, which helps to improve the accuracy of defect recognition. At this time, the characteristics of the defect echo signal are clearer and can better reflect the location, shape, size and other information of the defect.

[0192] Beneficial effects: Through decomposition and reconstruction, the defect signal can be effectively extracted from the complex echo signal, avoiding the misjudgment caused by noise interference in the traditional method. In the signal processing of multiple frequency bands, the noise frequency band can be accurately selected and removed, thereby greatly improving the signal-to-noise ratio of the signal. This method can adapt to different types of noise and echo signals of various materials, which is helpful for detecting defects in different welding joints. Through wavelet transform and frequency domain analysis, the slight differences of defect signals can be finely distinguished, improving the accuracy of detection.

[0193] The electronic device 400 may be a desktop computer, a notebook, a PDA, a cloud server, or other electronic device. The electronic device 400 may include, but is not limited to, a processor 401 and a memory 402. Those skilled in the art will appreciate that Figure 4 It is only an example of the electronic device 400 and does not constitute a limitation of the electronic device 400. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0194] The processor 401 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0195] The memory 402 may be an internal storage unit of the electronic device 400, for example, a hard disk or memory of the electronic device 400. The memory 402 may also be an external storage device of the electronic device 400, for example, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 400. Further, the memory 402 may also include both an internal storage unit of the electronic device 400 and an external storage device. The memory 402 is used to store the computer program 403 and other programs and data required by the electronic device. The memory 402 may also be used to temporarily store data that has been output or is to be output.

[0196] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present disclosure. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0197] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0198] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this disclosure.

[0199] In the embodiments provided in the present disclosure, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. Multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0200] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0201] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0202] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present disclosure implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. The computer program may include computer program code, and the computer program code may be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electric carrier signals and telecommunication signals.

[0203] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should all be included in the protection scope of the present disclosure.

Claims

1. An ultrasonic phased array automatic detection device for welding joints, characterized in that: include: A control computer is used for human-computer interaction, controlling the phased array ultrasonic transmitting / receiving module, receiving feedback signals, and communicating with the motion control module; A phased array ultrasonic transmitting / receiving module communicates with the control computer and is used to transmit and receive ultrasonic signals, perform parallel signal processing and data storage, and upload detection data to the control computer; Phased array probe, including 32-element linear array, element spacing is less than or equal to 0.3mm, and center frequency is greater than or equal to 10MHz; A motion control module, comprising a stepper motor control card and a stepper motor driver, wherein the stepper motor control card is connected to the control computer via a USB interface, and the stepper motor driver is used to drive the stepper motor to realize the movement of the detection device; A mechanical scanning mechanism, used for supporting and moving the phased array probe to perform mechanical scanning; The data transmission interface is used to implement TCP / IP protocol communication between the control computer and the phased array ultrasonic transmitting / receiving module.

2. The device according to claim 1, characterized in that The control computer runs the human-computer interaction software, including the following modules: Ultrasonic parameter and mechanical scanning parameter setting module, used to input sample thickness, sound velocity, focal depth, and automatically calculate the delay parameters of acoustic beam excitation; Ultrasonic excitation and reception module, used to control the excitation and reception of ultrasonic signals; A motion control module, used to control the mechanical scanning mechanism according to a preset scanning area, step angle and step speed; A signal processing and image display module, used for processing ultrasonic echo signals and generating scanned images; The data storage module is used to store and manage detection data.

3. The device according to claim 1, characterized in that The detection modes of the probe include longitudinal wave mode and shear wave mode. The longitudinal wave detection mode is coupled to the workpiece by direct coupling or rectangular wedges, and is used to detect defects parallel to the workpiece surface; The shear wave detection mode is coupled to the workpiece through wedges with different inclination angles and is used to detect defects that are perpendicular or inclined to the surface of the workpiece.

4. A method for automatic ultrasonic phased array detection of welded joints, characterized in that: include: Select longitudinal wave mode or transverse wave mode on the control computer interface, input the sample plate thickness, sound velocity and focal depth parameters, calculate the acoustic beam excitation delay and set it in the ultrasonic transmitting / receiving module; The scanning area, step angle and step speed are set on the control computer, and the motion control module drives the mechanical scanning mechanism according to the set parameters, so that the phased array probe moves along a preset path on the surface of the weld joint; The phased array ultrasonic transmitting / receiving module transmits ultrasonic waves to the welding joint according to the acoustic beam excitation delay and receives echo signals, processes the echo signals to obtain scanning signals and uploads them to the control computer; Processing the scanning signal to generate a scanning image and segmenting and identifying the scanning image to extract the defective areas of incomplete fusion and incomplete penetration in the scanning image; The defect area is visualized in three dimensions and a characteristic curve extracted from a primary echo amplitude of the echo signal is analyzed to obtain and store three-dimensional data of the defect area.

5. The method according to claim 4, characterized in that The method includes adopting direct coupling when detecting workpieces with a thickness greater than a first preset thickness or defects with a depth greater than a first preset depth in a longitudinal wave mode, and adopting rectangular wedge coupling when detecting workpieces with a thickness less than the first preset thickness or defects with a depth less than the first preset depth.

6. The method according to claim 4, characterized in that The method comprises configuring wedges with different inclination angles in a shear wave mode to make ultrasonic waves obliquely incident on the surface of the welding joint at a set incident angle, so as to detect defects that are perpendicular to the workpiece surface or distributed at an acute angle or an obtuse angle.

7. The method according to claim 4, characterized in that The method also includes separating the workpiece surface echo signal from the defect echo signal and suppressing the background noise when the distance between the middle layer unfused defects of the welding joint and the detection surface is less than 1.2 mm.

8. The method according to claim 4, characterized in that The method further comprises decomposing the echo signal to obtain signal components of different frequency bands, selecting the signal components according to noise distribution characteristics and reconstructing them to obtain defect echo signals.

9. An electronic device, characterized in that: include: one or more processors; A storage unit, used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors can implement the ultrasonic phased array automatic detection device and method for welding joints according to any one of claims 4 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it can implement the device and method for automatic ultrasonic phased array detection of welded joints according to any one of claims 4 to 8.

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