Ultrasonic phased array metal additive part frequency domain optimization imaging method, system and equipment

Abstract

The invention discloses a frequency domain optimization imaging method, system and equipment for an ultrasonic phased array metal additive part. The method comprises the following steps: step 1, confirming system parameters and equipment states before detection; 2, full-matrix capturing is conducted on the metal additive part through an ultrasonic phased array system, and complete ultrasonic signal data are obtained; and step 3, processing the acquired data by adopting a frequency domain phase shift offset algorithm so as to enhance the defect identification capability. And 4, introducing a symbol coherence factor algorithm to further optimize the data processed in the step 3, improving the defect resolution, and realizing accurate positioning and imaging of the defect. And 5, outputting an imaging result optimized in the step 4 to a host display, generating a visual defect visual image, and storing related data and image files. According to the method, an optimization algorithm and a frequency domain full-focusing method are organically combined, so that a clearer defect image is generated, and the defect resolution ratio and the defect positioning precision are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic nondestructive testing, and in particular relates to a frequency domain optimization imaging method, system and equipment for ultrasonic phased array metal additive parts. Background Art

[0002] In the traditional non-destructive testing of aviation blades, metal additive parts are increasingly used in high-end fields such as aerospace and nuclear power. Timely acquisition of defects and microstructure information is of great significance to improving the manufacturing process, ensuring product quality and the safe and stable operation of related equipment. However, the special manufacturing process causes serious attenuation of sound waves in metal additive parts, which brings great challenges to ultrasonic imaging. Therefore, it is urgent to apply effective ultrasonic non-destructive testing imaging methods.

[0003] As an improvement, an ultrasonic phased array frequency domain optimization imaging method for metal additive parts is proposed. After planning the scanning path of the contour of the inspected part, the ultrasonic phased array probe is installed at the end of the multi-axis scanning system. The scanning system drives the probe movement through the planned path, while ensuring that the center of the probe is always perpendicular to the inspected interface, thereby realizing efficient acquisition of ultrasonic data. During the imaging process, no additional operation is required, which greatly improves the acquisition efficiency and makes this method more suitable for actual production. However, traditional non-destructive testing still faces the problems of slow imaging speed and low imaging resolution for metal additive parts, which urgently need to be further optimized and solved. Summary of the invention

[0004] The purpose of the present invention is to provide a method, system and device for frequency domain optimization imaging of metal additive parts using ultrasonic phased array to solve the problems of insufficient imaging speed and poor imaging resolution in the current non-destructive testing of metal additive parts.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] The present invention provides a frequency domain optimization imaging method for ultrasonic phased array metal additive parts, which specifically comprises the following steps:

[0007] Step 1: Before testing, confirm system parameters and equipment status, check connections and operation, and ensure that experimental conditions meet requirements;

[0008] Step 2: Use the ultrasonic phased array probe to perform full matrix capture of the metal additive parts to obtain complete ultrasonic signal data;

[0009] Step 3: Use frequency domain phase shift algorithm to process the collected data to enhance the ability to identify defects;

[0010] Step 4: Add the symbol coherence factor algorithm to further process the data in step 3 to improve the defect resolution;

[0011] Step 5: Output the optimized imaging result in Step 4 to the host display to generate an intuitive defect visualization image, and store the relevant data and image files.

[0012] When implementing Step 1, verify the system parameters and device status, check the device connection and operation conditions to ensure that the experimental conditions meet the requirements.

[0013] When implementing Step 2, use a phased probe to collect ultrasonic full matrix signal data and read the signals in MATLAB.

[0014] When implementing Step 3, perform one-dimensional Fourier transform on the signal data using the Fourier transform function in MATLAB to obtain spectral data. To ensure the equivalence of the echo signals in the propagation time, the migration factor is corrected to Perform two-dimensional inverse Fourier transform to obtain the processed data.

[0015] When implementing Step 4, add the symbol coherence factor algorithm to obtain a weight matrix and multiply it with the data in Step 3.

[0016] When implementing Step 5, reconstruct the defect image of the metal additive manufacturing part according to the frequency domain phase shift offset algorithm; multiply according to the weight matrix of the symbol coherence factor algorithm, and apply the frequency domain full focusing method to obtain the optimized image.

[0017] The present invention also provides a frequency domain optimized imaging system for ultrasonic phased array metal additive manufacturing parts, including a placement unit for the metal additive manufacturing part to be measured, a data acquisition unit, an acquisition control unit, and an ultrasonic imaging unit. The specific functions are as follows:

[0018] The placement unit for the metal additive manufacturing part to be measured is used to provide a placement space for the metal additive manufacturing part to be measured;

[0019] The data acquisition unit is used to collect data of the metal additive manufacturing part to be measured and transmit the collected data of the metal additive manufacturing part to be measured to the acquisition control unit;

[0020] The acquisition control unit is used to control the actions of the data acquisition unit and transmit the data of the metal additive manufacturing part to be measured to the ultrasonic imaging unit;

[0021] The ultrasonic imaging unit is used to perform calculations and processing based on the data of the metal additive manufacturing part to be measured, and generate and output the defect frequency domain optimized image of the metal additive manufacturing part.

[0022] The above frequency domain optimized imaging method for ultrasonic phased array metal additive manufacturing parts is exactly implemented based on the above frequency domain optimized imaging system for ultrasonic phased array metal additive manufacturing parts.

[0023] Furthermore, the acquisition control unit includes an ultrasonic acquisition system, and the ultrasonic imaging unit consists of a host and a display; the host can display the frequency-domain optimized defect image of the metal additive manufacturing part through the display based on the defect signal data of the metal additive manufacturing part to be measured.

[0024] In addition, the present invention also provides a computer device, including a memory, a processor, and a computer program that can run on the processor. When the processor executes the program, it can implement the steps of the above-mentioned frequency-domain optimized imaging method for ultrasonic phased array metal additive manufacturing parts.

[0025] Compared with the prior art, the frequency-domain optimized imaging method, system, and device for ultrasonic phased array metal additive manufacturing parts of the present invention can effectively reduce the complex delay superposition calculation in the traditional time-domain algorithm by equating the sound velocity signal data of the metal additive manufacturing part to the sound velocity data of the metal additive manufacturing part and performing interpolation through the phase migration map in the frequency domain. This method can achieve real-time imaging of the ultrasonic phased array probe, is easy to operate, and at the same time provides images with high defect resolution, ensuring that the imaging range covered by the measurement probe can be quickly imaged and the defects can be clearly presented, thus achieving a fast and efficient detection effect. Description of the Drawings

[0026] Figure 1 is a schematic flowchart of the method in the frequency-domain optimized imaging method, system, and device for ultrasonic phased array metal additive manufacturing parts of the present invention;

[0027] Figure 2 is a schematic structural diagram of the system in the frequency-domain optimized imaging method, system, and device for ultrasonic phased array metal additive manufacturing parts of the present invention;

[0028] Figure 3 is a schematic algorithm flowchart of ultrasonic frequency-domain imaging in the frequency-domain optimized imaging method, system, and device for ultrasonic phased array metal additive manufacturing parts of the present invention;

[0029] Figure 4 is a schematic diagram of the frequency-domain optimized defect image of the metal additive manufacturing part in the frequency-domain optimized imaging method, system, and device for ultrasonic phased array metal additive manufacturing parts of the present invention;

[0030] Among them, 1. Multi-axis scanning system, 2. Test bench, 3. Metal additive manufacturing part, 4. Ultrasonic phased array probe, 5. Ultrasonic acquisition system, 6. Host, 7. Display. Detailed Embodiments

[0031] The present invention provides a frequency-domain optimized imaging method for ultrasonic phased array metal additive manufacturing parts, which specifically includes the following steps: Step 1: Confirm the system parameters and equipment status before detection, check the connection and operation, and ensure that the experimental conditions meet the requirements; Step 2: Perform full matrix capture on the metal additive manufacturing parts through an ultrasonic phased array probe to obtain complete ultrasonic signal data; Step 3: Use the frequency-domain phase shift migration algorithm to process the collected data to enhance the defect recognition ability; Step 4: Add the symbol coherence factor algorithm to further process the data in Step 3 to improve the defect resolution; Step 5: Output the optimized imaging result in Step 4 to the host display, generate an intuitive defect visualization image, and store the relevant data and image files.

[0032] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0033] As Figure 1 shown, Step 1: Confirm the system parameters and equipment status before detection, check the connection and operation, and ensure that the experimental conditions meet the requirements:

[0034] It is necessary to set the parameters of the ultrasonic phased array system in detail according to the detection requirements, including the number of array elements of the probe, excitation frequency, sampling frequency, and scanning path planning. At the same time, check the power supply, signal line connection, and probe coupling status of the equipment to ensure that the probe is in close contact with the surface of the metal additive manufacturing parts to avoid affecting the signal quality due to poor coupling. After completion of the confirmation, perform the initialization operation of the equipment to ensure the normal operation of the system and prepare for the formal detection.

[0035] Step 2: Perform full matrix capture on the metal additive manufacturing parts through an ultrasonic phased array probe to obtain complete ultrasonic signal data:

[0036] In the frequency-domain optimized imaging of metal additive manufacturing parts, a robotic arm holds an ultrasonic linear phased array probe with N array elements, and sequentially activates array elements 1 to N along the planned scanning path to collect full matrix signal data p(x, t), where x represents the position of the array element and t is the time of the ultrasonic data collected by the array element;

[0037] After removing the starting pulse part from the signal data p(x, t), determine the maximum value T(x) of the signal data on the time axis t at each array element position x, where x is the wafer position for collecting the signal data and t is the time of the signal data sampling point;

[0038] Step 3: Use the frequency-domain phase shift migration algorithm to process the collected data to enhance the defect recognition ability:

[0039] Perform one-dimensional Fourier transform on the metal additive manufacturing part signal data p(x, z = 0, t) in Step 2 along the x-axis to obtain p(k x , 0, ω), where k xThe wavenumber of the x-axis; during the process of downward extrapolation of the emitted wavefield to depth z, the migration factor is corrected to where k z is the wavenumber of the z-axis; after correction, p(k x , z, ω) is obtained, and the defect image I(x, z) of the metal additive manufacturing part is calculated through two-dimensional inverse Fourier transform.

[0040] Step 4: Add the symbol coherence factor algorithm to further process the data in Step 3 to improve defect resolution:

[0041] Further introduce the symbol coherence coefficient adaptive weighting (SCF) algorithm to optimize imaging. By improving the coherence of imaging, enhancing the contrast and clarity of defect features, more accurately highlighting the defect area, and further improving the imaging quality.

[0042] The symbol coherence coefficient is a relatively commonly used adaptive method. This method reconstructs the signal based on the positive and negative of the received signal. The phase information of the signal is expressed as:

[0043] S ij (t) = |S|e iφ = |S|(cosφ + i sinφ) (1)

[0044] So the SCF is:

[0045]

[0046] where sign is the signum function. The function is that if the real part of a number is greater than 0, the sign value is 1; if the real part is equal to 0, the sign value is 0; if the real part is less than 0, the sign value is -1. Here it is used to judge the positive and negative of the real part phase of the signal.

[0047] After multiplying the weight matrix W SCF (p) by the amplitude in the defect image I(x, z) of the metal additive manufacturing part in Step 3, the amplitude of the new image is:

[0048] I TFM-SCF (x, z) = W SCF (p)·I(x, z) (3)

[0049] Step 5: Output the optimized imaging result in Step 4 to the host computer monitor to generate an intuitive defect visualization image, and store the relevant data and image files:

[0050] Assume the emission from the m-th array element. If the propagation time from the emission array element to the scatterer (x, z) is τ(x, m, z), then the imaging condition will be processed at t = τ(x, m, z) instead of t = 0. Therefore, the imaging result at depth z can be expressed as:

[0051]

[0052] Then the reconstruction result of the entire defect imaging area is the superposition of wave field extrapolations under all transmitting array elements, and its expression is:

[0053]

[0054] Such as Figure 2 As shown, as a specific embodiment, in the frequency-domain optimized imaging method, system and device for ultrasonic phased array metal additive manufacturing parts of the present invention, an ultrasonic phased array frequency-domain optimized imaging system is adopted. An ultrasonic phased array probe 4 with 64 array elements is installed at the end of the multi-axis scanning system 1. After planning the scanning path on the surface of the test block of the metal additive manufacturing part 3, taking the detection of 0°, 30°, 45° and 60° cracks with a detection distance of 7 mm from the surface and a length of 2 mm in a certain scanning path as an example, the operation steps are as follows:

[0055] First, import the planned scanning path into the multi-axis scanning system 1, and set the excitation frequency to 10 MHz and the sampling frequency to 200 MHz in the host 6 for signal data acquisition. Excite the 1st to 64th array elements one by one in sequence. After each array element is excited, the ultrasonic signals are received simultaneously by all array elements. After 64 excitations, a total of 4096 ultrasonic A-scan reflection signals are obtained, and each A-scan signal has 8192 sampling points. When the multi-axis scanning system 1 clamps the ultrasonic phased array probe 4 and moves it directly above the crack defect, the collected defect ultrasonic echo data is saved in the host 6 in the form of a two-dimensional matrix, named p(x,t), and its size is 4096×8192. The first dimension of the matrix represents the coordinates of the receiving array elements, and the second dimension represents the sampling points of the ultrasonic data.

[0056] Specific implementation method of step 1: Before the detection starts, first verify whether the key parameters of the ultrasonic phased array system meet the experimental requirements, including the number of array elements of the probe, the excitation frequency, the sampling frequency, and whether the planning of the scanning path is reasonable. Subsequently, check the power connection of the equipment, the connection of the signal line, and the coupling condition between the probe and the surface of the metal additive manufacturing part to be measured to ensure that the equipment is in good operating condition and meets the operating specifications. After the above preparations are completed, start the equipment for initialization operations, perform self-checks on the system to ensure that all functional modules are working properly. According to the preset scanning path, configure and load the experimental parameters to prepare for subsequent detection and signal acquisition.

[0057] Specific implementation method of step 2: Along the preset scanning path, sequentially excite the 1st to 64th array elements in the linear array probe, and simultaneously receive the echo signal data p(x,t) of each array element, where x represents the position of the array element on the probe, and t is the sampling point on the data acquisition time axis. Preprocess the collected full matrix signal data p(x,t) to remove the initial pulse interference part to ensure the validity of the data.

[0058] As shown Figure 3 in the figure, the specific implementation of step 3: Read the metal additive manufacturing part signal data p(x, z = 0, t) obtained in step 2 in MATLAB software, and its matrix size is 4096×8192. Use the Fourier transform function of MATLAB to perform one-dimensional Fourier transform on the t-axis data of p(x, z = 0, t) to obtain the spectral data p(k x , 0, ω), where k x is the wave number of the x-axis, ω is the frequency axis, and the matrix size of p(k x , 0, ω) is 4096×8192. Then, multiply the matrix p(k x , 0, ω) by , where k z is the wave number of the z-axis and j is the imaginary unit, so as to obtain the corrected signal data p(k x , z, ω), and its matrix size is still 4096×8192. Finally, perform two-dimensional inverse Fourier transform on the corrected data to obtain the defect image I(x, z) of the metal additive manufacturing part, and its matrix size is also 4096×8192.

[0059] The specific implementation of step 4 is as follows: To further improve the imaging resolution, the symbol coherence factor (SCF) algorithm is introduced to process the data in step 3, and the phase of the received signal is decomposed. Let the signal S ij (t) = |S|e iφ = |S|(cosφ + isinφ), where |S| is the amplitude of the signal and φ is the phase information of the signal. Calculate the symbol coherence factor weight matrix W SCF (p), and its expression is where sign is the sign function. When the real part of the signal is greater than 0, sign = 1; when the real part is equal to 0, sign = 0; when the real part is less than 0, sign = -1. This function is used to judge the positive and negative of the real part phase of the signal. Multiply the calculated weight matrix W SCF (p) by the amplitude I(x, z) of the metal additive manufacturing part defect image generated in step 3 to obtain the optimized new image amplitude I SCF (x, z), and its expression is I SCF (x, z) = W SCF (p)·I(x, z).

[0060] The specific implementation of Step 5 is as follows: Assume that an ultrasonic signal is transmitted from the m-th element, and the propagation time of the ultrasonic wave to the scatterer position (x, z) is τ(x, m, z). Since the ultrasonic signal takes time to propagate, the imaging condition needs to be processed at t = τ(x, m, z) instead of t = 0. The received signal p(x, m, z, t) is transformed into the frequency domain, and the frequency-domain wavefield data p(k x , m, 0, ω) is obtained through two-dimensional Fourier transform, where k x is the transverse wave number and ω is the frequency component. The wavefield data of the m-th transmitting element is extrapolated to achieve signal reconstruction at depth z. Its mathematical expression is: Therefore, the imaging result at depth z can be expressed as where p(k x , m, 0, ω) is the wavefield data of the m-th transmitting element in the frequency domain, is the phase factor for extrapolating the frequency-domain wavefield to the position (x, z), and e jωτ is the time-phase term considering the propagation time τ(x, m, z). The extrapolation results of the wavefields of all transmitting elements are superimposed to achieve the reconstruction of the entire defect imaging area, such as the defect image shown in Figure 4 . The reconstructed image can be expressed as where I' TFM is the reconstructed image obtained by applying the frequency-domain full focusing method (F-TFM), and p(x, m, z, t) is the wavefield data of the m-th transmitting element extrapolated to the imaging area. Using an Intel Core i5 1135 type processor with a main frequency of 2.4 GHz and 16G of computing memory as the test platform, the running time of this algorithm in the MATLAB 2022b software environment is only 2.96 s.

[0061] A frequency-domain optimized imaging method, system, and device for ultrasonic phased array metal additive manufacturing parts of the present invention provide a frequency-domain optimized imaging system for ultrasonic phased array metal additive manufacturing parts. Based on this system, frequency-domain optimized imaging of metal additive manufacturing part defects can be provided, which can provide a data basis for subsequent operations and working conditions. By using the system and method of the present invention, the detection efficiency of ultrasonic phased array metal additive manufacturing parts can be improved, and the imaging speed and resolution can be enhanced. Moreover, the present invention interpolates through the phase migration map in the frequency domain, which can avoid the complex delay superposition calculation caused by the interface in the traditional time-domain algorithm, thereby simplifying the calculation difficulty and improving the accuracy and applicability.

[0062] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0063] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be realized by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded processors, or other programmable data processing devices to generate a machine, so that the instructions executed by the processors of the computer or other programmable data processing devices generate means for realizing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0064] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Ultrasonic phased array frequency domain optimization imaging method for metal additive parts, characterized in that: The specific steps include: Step 1: Before testing, confirm system parameters and equipment status, check connections and operation, and ensure that experimental conditions meet requirements; Step 2: Use the ultrasonic phased array probe to perform full matrix capture of the metal additive parts to obtain complete ultrasonic signal data; Step 3: Use frequency domain phase shift algorithm to process the collected data to enhance defect recognition capability; Step 4: Introduce the symbol coherence factor algorithm to further optimize the data in step 2 and improve the defect resolution; Step 5: Output the optimized imaging results in step 4 to the host display, generate an intuitive defect visualization image, and store relevant data and image files.

2. The frequency domain optimization imaging method of ultrasonic phased array metal additive parts according to claim 1 is characterized in that: In step 1, before testing, confirm that the parameters of the ultrasonic phased array system are set correctly, check the equipment connection and operation status, ensure that the probe is well coupled with the workpiece to be tested, and perform the test; verify that the experimental environment meets the requirements and ensure that the test conditions are stable and reliable.

3. The frequency domain optimization imaging method of ultrasonic phased array metal additive parts according to claim 1, characterized in that: In step 2, the self-transmitted and self-received data are collected by an ultrasonic phase-controlled probe and the signal data is read.

4. The method for frequency domain optimization imaging of metal additive parts using ultrasonic phased array according to claim 1, characterized in that: In step 3, the signal data is subjected to a one-dimensional Fourier transform using a Fourier transform function to obtain spectrum data; to ensure the equivalence of the echo signal propagation time, the migration factor is corrected to And perform two-dimensional inverse Fourier transform to obtain processed data.

5. The frequency domain optimization imaging method of ultrasonic phased array metal additive parts according to claim 1, characterized in that: In step 4, a weight matrix is ​​generated by a symbolic coherence factor algorithm and multiplied with the processed data in step 3.

6. The method for frequency domain optimization imaging of metal additive parts using ultrasonic phased array according to claim 1, characterized in that: In step 5, the defect image of the metal additive part is reconstructed by combining the frequency domain phase shift algorithm, and the weight matrix generated by the symbolic coherence factor algorithm is multiplied by the result, and finally the optimized image is generated by the frequency domain full focusing method.

7. An ultrasonic phased array frequency domain optimization imaging system for metal additive parts implementing the method described in any one of claims 1 to 6, characterized in that: include: A metal additive part placement unit to be tested, a data acquisition unit, an acquisition control unit and an ultrasonic imaging unit; wherein: the metal additive part placement unit to be tested is used to provide a storage space for the metal additive part to be tested; the data acquisition unit is used to collect data of the metal additive part to be tested and transmit it to the acquisition control unit; the acquisition control unit is used to control the operation of the data acquisition unit and transmit the collected data to the ultrasonic imaging unit; The ultrasonic imaging unit is used to perform calculations and processing based on the collected data, and output frequency domain optimized images of defects in metal additive parts.

8. The ultrasonic phased array frequency domain optimization imaging system for metal additive parts according to claim 7, characterized in that: The data acquisition unit comprises a multi-axis scanning system (1) and an ultrasonic phased array probe (4) arranged at the end thereof, the metal additive product placement unit to be tested comprises a test bench (2), and the acquisition control unit can control the multi-axis scanning system (1) to drive the ultrasonic phased array probe (4) to detect the metal additive product to be tested in the test bench (2).

9. The ultrasonic phased array frequency domain optimization imaging system for metal additive parts according to claim 8, characterized in that: The acquisition control unit comprises an ultrasonic acquisition system (5), and the ultrasonic imaging unit comprises a host (6) and a display (7); the host (6) is capable of outputting a frequency domain optimized defect image of the metal additive part through the display (7) based on the data of the metal additive part to be tested.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for frequency domain optimization imaging of ultrasonic phased array metal additive parts according to any one of claims 1 to 6 are implemented.

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