Array type ultrasonic synthetic aperture focusing analysis method for imaging recognition of grouting sleeve in fabricated building

Abstract

The invention discloses an array type ultrasonic synthetic aperture focusing analysis method for imaging recognition of a grouting sleeve in a prefabricated building. The method comprises the steps of SH ultrasonic data collection, wherein the SH ultrasonic data collection comprises the steps of measuring the size of a component, drawing collection grid lines and transmitting and receiving ultrasonic signals; synthetic aperture focusing SH ultrasonic data analysis, including ultrasonic data preprocessing, frequency analysis setting, wavelet transform and Wiener filter processing analysis, and synthetic aperture focusing analysis; synthetic aperture focusing numerical matrix imaging, including SAFT numerical matrix imaging and image reconstruction; the grouting sleeve space position and size identification comprises grouting sleeve area identification and grouting sleeve size calibration. According to the method, the SH ultrasonic technology is combined with the synthetic aperture focusing and filtering method, the detection precision is effectively improved, by means of the technology, high-resolution imaging of the grouting sleeve can be obtained, the spatial position of the grouting sleeve can be accurately positioned, the area information of the grouting sleeve can be accurately measured, and the detection efficiency and accuracy are greatly improved.

Description

Technical Field

[0001] The invention relates to a grouting sleeve imaging recognition method, in particular to an array type ultrasonic synthetic aperture focusing analysis method for imaging recognition of grouting sleeves inside assembled buildings. Background Art

[0002] Prefabricated buildings have outstanding advantages and are one of the key technologies promoted and applied in the current construction industry. Grouting sleeves are the most important connection method for prefabricated buildings. Prefabricated buildings reduce material waste and energy consumption through factory production, shorten construction time and reduce pollution, achieving energy conservation, environmental protection and sustainable development. Its modular design not only improves efficiency, but also significantly saves water resources and reduces environmental disturbance, providing important support for the green transformation and carbon emission reduction of the construction industry.

[0003] However, due to the complexity of its internal state and the high requirements for monitoring, traditional detection methods face many challenges. In particular, although ultrasonic technology is widely used, traditional methods are usually limited by factors such as a single channel and the complexity of concrete components, resulting in low reliability of detection results and complex signal analysis. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to propose an array ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings, which can obtain high-resolution imaging of grouting sleeves.

[0005] Technical solution: The present invention comprises the following steps:

[0006] SH ultrasonic data acquisition: including measuring component dimensions, drawing acquisition grid lines, and transmitting and receiving ultrasonic signals;

[0007] Synthetic aperture focusing SH ultrasonic data analysis: including ultrasonic data preprocessing, frequency analysis settings, wavelet transform filter and Wiener filter processing analysis, synthetic aperture focusing analysis;

[0008] Synthetic aperture focusing numerical matrix imaging: including SAFT numerical matrix imaging and image reconstruction;

[0009] Identification of spatial position and size of grouting sleeve: including grouting sleeve area identification and grouting sleeve size calibration.

[0010] The ultrasonic data preprocessing is specifically as follows: reading a specified binary file, reshaping the data into a matrix, drawing a filled contour map, and reversing the Y axis to intuitively display the data distribution and facilitate data observation.

[0011] The frequency analysis setting is used to select to allow signals within a set frequency range to pass through, while suppressing signals outside the frequency range.

[0012] The frequency analysis settings specifically include:

[0013] The bandpass Elliptic filter is introduced first, and the ultrasonic data is selectively enhanced by setting the passband frequency and stopband frequency parameters to accurately extract the characteristic frequency information of the corresponding position of the grouting sleeve;

[0014] A bandpass Butterworth filter is used to refine the ultrasonic data. By setting the passband frequency and stopband frequency parameters, the frequency range is limited to the passband frequency and stopband frequency range of the aforementioned bandpass Elliptic filter, and the characteristic frequency of the grouting sleeve position is accurately extracted, significantly suppressing noise and clutter interference.

[0015] The wavelet transform filter and Wiener filter processing analysis specifically include:

[0016] Introducing wavelet transform filters to perform multi-scale decomposition and reconstruction of frequency-set ultrasonic data: decomposing ultrasonic data into different frequency components and providing high-resolution multi-scale analysis in both the time domain and the frequency domain;

[0017] The Wiener filter is used to construct an optimization model based on the minimum mean square error for the ultrasonic data after wavelet transform filtering, and the best approximation of the original ultrasonic data is estimated. The filter dynamically adjusts the filter parameters to achieve adaptive optimization, thereby effectively suppressing noise while retaining the key feature information of the ultrasonic data to achieve optimal noise suppression.

[0018] The synthetic aperture focusing numerical matrix imaging obtains the numerical value of the image by adopting an image focusing method.

[0019] The synthetic aperture focusing numerical matrix imaging can perform multi-side and multi-view coherent superposition processing on the filtered ultrasonic data, enhance the imaging quality of the signal, and achieve high-precision reconstruction and feature extraction of the internal structure of the grouting sleeve.

[0020] The SAFT numerical matrix imaging utilizes an algorithm writing platform to image the numerical matrix, reconstructs the image according to numerical superposition at different angles, improves the resolution of the image, and emphasizes the grouting sleeve area inside the prefabricated building, including the size and shape of the grouting sleeve.

[0021] The spatial position and size identification of the grouting sleeve is specifically as follows: first, based on the global statistical distribution of the numerical matrix image, the area showing a strong signal response in the numerical matrix image is divided into multiple independent areas, and the numerical threshold is set through the algorithm programming platform to draw contour lines for each independent area, and the area above the set threshold is automatically identified and circled. This area is the grouting sleeve, and then the area calculation of the area is realized through the algorithm programming platform.

[0022] The drawing of acquisition grid lines is used to determine the data acquisition position and perform scanning and acquisition from different angles.

[0023] Beneficial effects: The present invention has the following advantages:

[0024] (1) The SH ultrasonic technology is combined with synthetic aperture focusing (SAFT) and filtering methods to effectively improve the detection accuracy. This technology can be used to obtain high-resolution imaging of the grouting sleeve, accurately locate its spatial position, and accurately measure its area information, greatly improving the detection efficiency and accuracy. In addition, the multi-channel and signal processing capabilities of the SH ultrasonic technology enable it to overcome the limitations of traditional ultrasonic technology in complex structures and ensure comprehensive monitoring of the grouting sleeve, thus providing a more reliable and efficient technical means for detection.

[0025] (2) Based on the effects of the four filters, clutter can be effectively filtered out to improve imaging clarity;

[0026] (3) Through the analysis of SAFT numerical matrix imaging and image reconstruction, the position of the grouting sleeve inside the prefabricated building can be accurately identified;

[0027] (4) It is possible to identify and calibrate the grouting sleeve area, select the area above the set numerical threshold, draw contour lines, and display the area of ​​the grouting sleeve inside the prefabricated building;

[0028] (5) Through accurate and intuitive imaging effects, non-professional technical personnel can intuitively and clearly identify the location and area of ​​the grouting sleeve inside the prefabricated building;

[0029] (6) The algorithm analysis based on synthetic aperture focusing has fast and clear analysis steps, which is suitable for non-destructive detection and identification inside various types of prefabricated structures and has a certain degree of versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a flow chart of the present invention;

[0031] Figure 2 It is a two-dimensional cross-sectional schematic diagram of non-destructive testing of grouting sleeves in prefabricated concrete column structures;

[0032] Figure 3 This is the cross-sectional distribution diagram of the grouting sleeve in the prefabricated concrete column structure;

[0033] Figure 4 It is a schematic diagram for calibrating the size of the grouting sleeve of the prefabricated concrete column structure;

[0034] Figure 5It is a two-dimensional cross-sectional schematic diagram of non-destructive testing of grouting sleeves in prefabricated concrete wall structures;

[0035] Figure 6 It is the cross-sectional distribution diagram of the grouting sleeve in the prefabricated concrete wall structure;

[0036] Figure 7 This is a schematic diagram for calibrating the size of grouting sleeves for prefabricated concrete wall structures. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings.

[0038] Example 1

[0039] like Figure 1 As shown, the array-type ultrasonic synthetic aperture focusing analysis method for imaging and identifying the grouting sleeve inside the prefabricated building of this embodiment includes the following steps:

[0040] S1, SH ultrasonic data acquisition: including measuring component dimensions, drawing acquisition grid lines, and transmitting and receiving ultrasonic signals.

[0041] When measuring the size of a component, if the aspect ratio of a rectangular component is greater than 5 and the width is above 20 cm, the four sides are sampled; if the aspect ratio of a rectangular component is less than or equal to 5 and the width is below 20 cm, the two small sides do not need to be sampled; the sampling area for a cylindrical component is three quarters of its side area; the specific operating procedures depend on the specific circumstances.

[0042] Draw collection grid lines to determine the data collection position and perform scanning and collection from different angles. When drawing the collection grid lines, the longitudinal spacing is 1 cm and the lateral spacing is 10 cm. The number of ultrasonic probes in the ultrasonic signal transmitting and receiving device is not less than 32, and the ultrasonic wave is SH wave.

[0043] S2. Synthetic aperture focusing SH ultrasonic data analysis: including ultrasonic data preprocessing, frequency analysis setting, wavelet transform and Wiener filter processing analysis, and synthetic aperture focusing analysis.

[0044] S21. Ultrasonic data preprocessing: Read the specified binary file, reshape the data into a matrix, draw a filled contour plot, and invert the Y-axis to intuitively display the data distribution and facilitate data observation.

[0045] S22, frequency analysis setting, is used to select to allow signals within a certain frequency range to pass through, while suppressing signals outside the frequency range, specifically including:

[0046] S221. Prioritize the introduction of bandpass Elliptic filter, and selectively enhance the ultrasonic data by setting the passband frequency and stopband frequency parameters, accurately extract the characteristic frequency information of the corresponding position of the grouting sleeve, and achieve high-resolution imaging of the grouting sleeve area;

[0047] S222. A bandpass Butterworth filter is used to perform fine processing on the ultrasonic data. By setting the passband frequency and stopband frequency parameters, its frequency range is strictly limited to the passband frequency and stopband frequency range of the aforementioned bandpass Elliptic filter, thereby more accurately extracting the characteristic frequency of the grouting sleeve position and significantly suppressing noise and clutter interference.

[0048] S23, wavelet transform and Wiener filter processing analysis, the signal is decomposed into different frequency components through the wavelet transform filter, and can be processed in the time domain and frequency domain at the same time; the role of the Wiener filter is to minimize the average error between the filtered signal and the real signal, and both filters play a role in noise removal and clutter reduction. Specifically, the following steps are included:

[0049] S231, introduce wavelet transform filter to perform multi-scale decomposition and reconstruction on the ultrasonic data that has been frequency-set. This method decomposes the ultrasonic data into different frequency components, realizes denoising and optimization processing of each component, and combines the characteristics of wavelet basis function to provide high-resolution multi-scale analysis capabilities in both time domain and frequency domain, providing a more reliable data foundation for subsequent imaging recognition;

[0050] S232, using a Wiener filter, constructing an optimization model based on minimum mean square error (MMSE) for the ultrasonic data after wavelet transform filtering, and estimating the best approximation of the original ultrasonic data. The filter dynamically adjusts the filter parameters to achieve adaptive optimization, thereby effectively suppressing noise while retaining key feature information of the ultrasonic data to achieve optimal noise suppression.

[0051] S3, synthetic aperture focusing numerical matrix imaging, by using the image focusing method, the numerical value of the image is obtained: including SAFT numerical matrix imaging and image reconstruction. SAFT numerical matrix imaging uses the algorithm writing platform to image the numerical matrix, reconstructs the image according to the numerical superposition of different angles, improves the image resolution, and emphasizes the grouting sleeve area inside the prefabricated building, including the size and shape of the grouting sleeve.

[0052] Synthetic aperture focusing numerical matrix imaging enhances the imaging quality of the signal by performing coherent superposition processing of filtered ultrasonic data from multiple sides and multiple perspectives, thereby achieving high-precision reconstruction and feature extraction of the internal structure of the grouting sleeve.

[0053] S4. Identification of the spatial position and size of the grouting sleeve: including grouting sleeve area identification and grouting sleeve size calibration, specifically: firstly, based on the global statistical distribution of the numerical matrix image, the area showing a strong signal response in the numerical matrix image is divided into multiple independent areas, and the numerical threshold is set through the algorithm programming platform to draw contour lines for each independent area, and the area above the set threshold is automatically identified and circled. This area is the grouting sleeve, and then the area calculation of the area is realized through the algorithm programming platform.

[0054] Example 2

[0055] Imaging of the internal grouting sleeve of prefabricated concrete columns: Making prefabricated concrete column components, such as Figure 2 As shown, the column size is 50cm×50cm×70cm. When the test block is cast, multiple grouting sleeves 2 with a diameter of 45mm are pre-buried. The distribution of the grouting sleeves 2 is as follows: Figure 3 The concrete components were cured under standard conditions for 28 days.

[0056] The four side surfaces of the formed concrete column component are divided into collection grid points, the horizontal collection interval of the grid points is set to 10 cm, and the vertical collection interval is set to 1 cm. The ultrasonic instrument 1 is used to collect ultrasonic data according to the points divided by the collection grid. Figure 2 The side view of the ultrasonic instrument 1 and the concrete column component during data collection is shown. It can be seen from the figure that the ultrasonic instrument 1 is placed directly in front of the grouting sleeve 2, and the four sides of the concrete column component are collected in turn. The single-side collection size is 40cm*50cm.

[0057] Based on the collected ultrasonic data, the ultrasonic data is preprocessed at the beginning of the synthetic aperture focusing analysis. Secondly, the bandpass Elliptic filter is used to set the frequency analysis of the ultrasonic data. The passing frequency is measured and calculated to be between 24.6kHZ and 37kHZ, and the stop frequency is below 15kHZ and above 41kHZ. Secondly, the bandpass Butterworth filter is used to set the frequency analysis of the ultrasonic data. The passing frequency is measured and calculated to be between 12kHZ and 19.6kHZ, and the stop frequency is below 10kHZ and above 20kHZ. Then the wavelet transform filter and the Wiener filter are used for processing and analysis respectively.

[0058] Based on the analysis of the four filter denoising process, synthetic aperture focusing analysis is started to obtain the numerical value of the image. The obtained numerical matrix is ​​used to realize numerical matrix imaging through the algorithm programming platform, such as Figure 4 As shown, a two-dimensional image of the internal grouting sleeve of concrete based on the numerical matrix is ​​shown. The right side of the image shows the correspondence between the numerical value and the color. The red area is the high numerical area, the blue area is the low numerical area, and the middle of the color column is the transition area, corresponding to different numerical values.

[0059] like Figure 4 As shown in the figure, the grouting sleeve area is identified, and the area showing strong signal response in the numerical matrix image is divided into 12 independent areas. The average value of each independent area is calculated through the algorithm programming platform, and the threshold is set at 1.3 times the average value of each area. The contour line is used to automatically identify and circle the area above the set threshold. It can be inferred that the nearly circular area is the grouting sleeve in the concrete. The grouting sleeve domain of the synthetic aperture focusing imaging is basically consistent with the actual buried grouting sleeve in size and position. The area error percentage is shown in Table 1.

[0060] Table 1 Area error percentage

[0061]

[0062] It can be seen that the synthetic aperture focusing analysis method for imaging and identifying the internal grouting sleeve of prefabricated buildings has the ability to non-destructively detect the structure of the grouting sleeve inside the concrete structure. The synthetic aperture can provide information such as the size and spatial position of the grouting sleeve, which is fully confirmed in this embodiment.

[0063] Example 3

[0064] Imaging of the internal grouting sleeve of prefabricated concrete columns: Making prefabricated concrete wall components, such as Figure 5 As shown in the figure, the dimensions of the wall are 20cm×90cm×70cm. Grouting sleeves with a diameter of 42mm were pre-buried during the casting of the test block. The distribution of the grouting sleeves is shown in the figure. Figure 6 The concrete components were cured under standard conditions for 28 days.

[0065] The two side surfaces of the formed concrete wall components are divided into collection grid points. The horizontal collection interval of the grid points is set to 10 cm, and the vertical collection interval is set to 1 cm. Ultrasonic data are collected using an ultrasonic instrument according to the points divided by the collection grid. Figure 5 The side view of the ultrasonic instrument 1 and the concrete wall component during data collection is shown. As can be seen from the figure, the ultrasonic instrument 1 is placed directly in front of the grouting sleeve 2, and collects data from two sides of the concrete wall component in turn. The single-side collection size is 40cm*90cm.

[0066] Based on the collected ultrasonic data, the ultrasonic data is preprocessed at the beginning of synthetic aperture focusing analysis. Secondly, the frequency analysis of the ultrasonic data is set by using a bandpass Elliptic filter, and the passing frequency is measured and calculated to be between 25kHZ and 56.8kHZ, and the stop frequency is below 20kHZ and above 68kHZ. Secondly, the frequency analysis of the ultrasonic data is set by using a bandpass Butterworth filter, and the passing frequency is measured and calculated to be between 24.1kHZ and 52.6kHZ, and the stop frequency is below 15kHZ and above 55kHZ. Then, the wavelet transform filter and Wiener filter are used for processing and analysis respectively.

[0067] Based on the analysis of the four filter denoising process, the synthetic aperture focusing analysis is started to obtain the numerical value of the image. The obtained numerical matrix is ​​used to realize numerical imaging through the algorithm programming platform, such as Figure 7 As shown, a numerical-based two-dimensional image of the internal grouting sleeve of concrete is shown. The right side of the image shows the correspondence between the numerical value and the color. The red area is the high-intensity area, the blue area is the low-intensity area, and the middle of the color column is the transition area, corresponding to different intensity values.

[0068] like Figure 7 As shown, the grouting sleeve area is identified, and the area showing strong signal response in the numerical matrix image is divided into 12 independent areas. The average value of each independent area is calculated through the algorithm programming platform, and the threshold is set to 1.3 times the average value of each area. The contour line is used to automatically identify and circle the area above the set threshold. It can be inferred that the nearly circular area is the grouting sleeve in the concrete. The grouting sleeve domain focused by the synthetic aperture is basically completely consistent with the actual buried grouting sleeve in shape, size and position. The area error percentage is shown in Table 2.

[0069] Table 2 Area error percentage

[0070]

[0071] It can be seen that the synthetic aperture focusing analysis method for imaging and identifying the internal grouting sleeve of prefabricated buildings has the ability to non-destructively detect the structure of the grouting sleeve inside the concrete structure. The synthetic aperture can provide information such as the shape, size, and spatial position of the grouting sleeve, which is fully confirmed in this embodiment.

Claims

1. An array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings, characterized in that: The following steps are involved: SH ultrasonic data acquisition: including measuring component dimensions, drawing acquisition grid lines, and transmitting and receiving ultrasonic signals; Synthetic aperture focusing SH ultrasonic data analysis: including ultrasonic data preprocessing, frequency analysis settings, wavelet transform filter and Wiener filter processing analysis, synthetic aperture focusing analysis; Synthetic aperture focusing numerical matrix imaging: including SAFT numerical matrix imaging and image reconstruction; Identification of spatial position and size of grouting sleeve: including grouting sleeve area identification and grouting sleeve size calibration.

2. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 1 is characterized in that: The ultrasonic data preprocessing specifically includes: reading a specified binary file, reshaping the data into a matrix, and drawing a filled contour map.

3. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 1 or 2, characterized in that: The frequency analysis setting is used to select to allow signals within a set frequency range to pass through, while suppressing signals outside the frequency range.

4. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 3 is characterized in that: The frequency analysis settings specifically include: The bandpass Elliptic filter is introduced first, and the ultrasonic data is selectively enhanced by setting the passband frequency and stopband frequency parameters to accurately extract the characteristic frequency information of the corresponding position of the grouting sleeve; A bandpass Butterworth filter is used to refine the ultrasonic data. By setting the passband frequency and stopband frequency parameters, the frequency range is limited to the passband frequency and stopband frequency range of the aforementioned bandpass Elliptic filter, and the characteristic frequency of the grouting sleeve position is accurately extracted.

5. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 4 is characterized in that: The wavelet transform filter and Wiener filter processing analysis specifically include: Introducing wavelet transform filters to perform multi-scale decomposition and reconstruction of frequency-set ultrasonic data: decomposing ultrasonic data into different frequency components and providing high-resolution multi-scale analysis in both the time domain and the frequency domain; The Wiener filter is used to construct an optimization model based on minimum mean square error for the ultrasonic data after wavelet transform filtering to estimate the best approximation of the original ultrasonic data.

6. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 1 is characterized in that: The synthetic aperture focusing numerical matrix imaging obtains the numerical value of the image by adopting an image focusing method.

7. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 5 is characterized in that: The synthetic aperture focusing numerical matrix imaging can perform coherent superposition processing of filtered ultrasonic data from multiple sides and multiple viewing angles.

8. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 7 is characterized in that: The SAFT numerical matrix imaging utilizes an algorithm writing platform to image the numerical matrix and reconstructs the image according to numerical superposition at different angles.

9. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 7 is characterized in that: The spatial position and size identification of the grouting sleeve is specifically as follows: first, based on the global statistical distribution of the numerical matrix image, the area showing a strong signal response in the numerical matrix image is divided into multiple independent areas, and the numerical threshold is set through the algorithm programming platform to draw contour lines for each independent area, and the area above the set threshold is automatically identified and circled. This area is the grouting sleeve, and then the area calculation of the area is realized through the algorithm programming platform.

10. The array-based ultrasonic synthetic aperture focusing analysis method for imaging and identifying grouting sleeves inside prefabricated buildings according to claim 1 is characterized in that: The drawing of acquisition grid lines is used to determine the data acquisition position and perform scanning and acquisition from different angles.

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