A method, device, equipment and medium for measuring ultrasonic wave velocity of a concrete structure

Abstract

This invention discloses a method, device, equipment, and medium for measuring ultrasonic velocity in concrete structures, belonging to the field of concrete structure safety monitoring technology. It solves the problem of large fluctuations and low accuracy in measurement results caused by noise interference in existing first-wave interferometry methods. The method first collects multiple sets of ultrasonic signals from an intact concrete area and a target area to obtain two signal sets. First-wave interferometry is then performed on each signal set, pairing signals within the same set to complete consistency verification. Next, cross-correlation first-wave interferometry is performed on all paired signals from the two signal sets to obtain an initial time-of-arrival (TOA) dataset. Subsequently, the dataset is grouped and filtered, and the TOA data is sorted based on cross-correlation coefficients to correct deviations. The resulting data is then fused to obtain the final interferometric TOA. Finally, the TOA is substituted into the first-wave interferometric velocity calculation equation to solve for the ultrasonic velocity in the target area. This invention effectively reduces the influence of environmental and system noise, stabilizes the calculation results, improves measurement accuracy, and provides an accurate basis for the health evaluation of concrete structures.

Description

Technical Field

[0001] This invention relates to the field of concrete structure safety monitoring technology, specifically to a method, device, equipment, and medium for ultrasonic velocity measurement of concrete structures. Background Technology

[0002] Ultrasonic velocity measurement of concrete structures involves exciting ultrasonic signals on the surface of the concrete structure and receiving the ultrasonic signals at other locations. The measurement is performed by measuring the distance between the receiving and exciting locations. Simultaneously, the propagation time of the excitation signal is measured. Thus, the wave speed can be calculated. The main challenge in ultrasonic velocity measurement lies in the propagation time. The precise determination.

[0003] The commonly used measurement method is the first-wave interferometry, which is based on a known measurement distance. and Two measurements were performed under the given conditions, and the wave velocity of the first measurement result was... Given the wave velocity from another measurement. Unknown; by interfering with the waveforms of the first ultrasonic wave packets obtained from two measurements, that is, fixing the position of one waveform on the time axis and moving the second waveform to maximize the cross-correlation coefficient between the two, the distance moved by the second waveform can be determined. This is denoted as the time difference between their arrival times. At this point, a more accurate wave speed value can be obtained by averaging multiple measurements.

[0004] Under normal circumstances, when the operating conditions remain unchanged, the first The measurement obtained and the The difference obtained from the second measurement and the period of the excitation signal ratio It is stable, or the fluctuation range caused by error is very small; however, due to the influence of noise generated by the environment, the measuring personnel, and the system, the first-wave interferometry will produce a large error in the process of multiple measurements in practical applications, causing the above ratio to fluctuate greatly. At this time, directly averaging the measurement results will seriously lose the measurement accuracy. Summary of the Invention

[0005] In view of the above problems, the present invention provides a method, apparatus, equipment and medium for measuring ultrasonic velocity in concrete structures. Addressing the issue that existing first-wave interferometry methods for measuring ultrasonic velocity in concrete structures are susceptible to noise interference, leading to large fluctuations and low accuracy in measurement results, the present invention effectively reduces noise interference, stabilizes measurement results, and improves the measurement accuracy of ultrasonic velocity in concrete by using signal consistency verification within the same group, cross-group fully paired cross-correlation interferometry, and time-difference data correction and fusion based on cross-correlation coefficient sorting. This provides an accurate reference for the health assessment of concrete structures.

[0006] In a first aspect, embodiments of the present invention provide a method for measuring the ultrasonic velocity of a concrete structure, characterized in that an ultrasonic excitation source and a receiving sensor are set on the surface of the concrete structure to collect ultrasonic signals, and the propagation time difference is calculated through first-wave interferometry to solve for the ultrasonic velocity. The method includes: Multiple sets of ultrasonic received signals were collected from the intact area of ​​the concrete structure with known wave velocity and the target area with the wave velocity to be measured, respectively, and two sets of signal sets were obtained accordingly. Perform first-wave interference on each pair of signals within the same group for the two signal sets to complete the signal consistency verification. Each signal in the intact region signal set is paired with each signal in the target region signal set. Cross-correlation first-wave interferometry is performed on each pair of paired signals to obtain the initial time difference of arrival dataset. The initial time difference dataset is grouped and filtered, and the deviation time difference data is corrected a second time based on the cross-correlation coefficient. The final interferometric arrival time difference is obtained by fusion. The ultrasonic velocity in the target area is calculated based on the time difference of arrival of the final interference.

[0007] In some embodiments, before acquiring ultrasonic signals, ultrasonic excitation sources and receiving sensors are respectively deployed in the intact area and the target area, and the straight-line distance between the excitation source and the receiving sensor in the two areas is measured to calibrate the period of the excitation signal and the signal sampling interval.

[0008] In some embodiments, the ultrasonic received signals of the intact region and the target region are acquired n times using the same excitation and acquisition parameters, where n is a positive integer greater than or equal to 3, thereby obtaining the signal set of the intact region and the signal set of the target region.

[0009] In some embodiments, all acquired ultrasonic received signals are first preprocessed by bandpass filtering, with the passband of the bandpass filter set centered on the excitation frequency of the excitation source.

[0010] In some embodiments, the criteria for determining signal consistency verification are: the arrival time difference obtained by the first wave interference of any pair of paired signals in the same group is less than a preset sampling interval multiple threshold; if the criteria are not met, the signal is re-acquired until the requirements are met.

[0011] In some embodiments, the execution process of the cross-correlation first-wave interference includes: An interference window of fixed length is set on the time axis. The time axis position of the intact region signal in the paired signal is fixed. The signal in the interference window of the target region signal is moved along the time axis. The cross-correlation coefficient of the two signals is calculated at different moving distances. The moving distance corresponding to the maximum value of the cross-correlation coefficient is taken as the initial arrival time difference of the paired signals.

[0012] In some embodiments, the rules for group filtering include: Using the arrival time difference obtained by pairing and interfering the first signal from the intact region with the first signal from the target region as the baseline value, and using half the period of the excitation signal as the threshold, the initial time difference dataset is divided into two groups: For the compliant group whose absolute difference from the benchmark value is less than half a period, and the deviation group whose absolute difference from the benchmark value is greater than half a period, calculate the average of the two groups and the overall average of the initial time difference dataset.

[0013] In some embodiments, the secondary correction step includes: Compare the absolute values ​​of the differences between the mean of the compliant group, the mean of the deviation group, and the overall mean of the dataset, and select the group with the larger absolute value of the difference as the group to be corrected; For each time difference data pair corresponding to a correction group, the time difference corresponding to the second peak value is searched sequentially in descending order of cross-correlation coefficient. The original time difference data is replaced with the searched time difference until the replaced time difference data can be classified into the compliance group.

[0014] In some embodiments, after all the data to be corrected has been replaced, the arithmetic mean of the updated time difference dataset is calculated, and the arithmetic mean is used as the final time difference of arrival for the interferometry.

[0015] In some embodiments, the ultrasonic velocity in the target region is solved by the first-wave interference velocity calculation equation, the expression of which is:

[0016] In the formula, The straight-line distance between the excitation source and the receiving sensor within the intact area, For the known ultrasonic speeds in the intact region, c1 represents the straight-line distance between the excitation source and the receiving sensor within the target area, c2 represents the speed of the ultrasonic wave to be measured in the target area, and Δt represents the time difference of arrival of the final interference.

[0017] Secondly, embodiments of the present invention provide an ultrasonic velocity measuring device for concrete structures, the device comprising: The acquisition module is used to acquire multiple sets of ultrasonic received signals from the intact area of ​​the concrete structure with known wave velocity and the target area with the wave velocity to be measured, respectively, and obtain two sets of signal sets. The consistency verification module is used to perform the first-wave interference of pairwise combinations of signals within the same group on the two signal sets to complete the signal consistency verification. The first-wave interferometry module is used to pair each signal in the intact region signal set with each signal in the target region signal set, and perform cross-correlation first-wave interferometry on each pair of paired signals to obtain the initial time difference of arrival dataset. The filtering and correction module is used to group and filter the initial time difference dataset, sort the deviation time difference data based on the cross-correlation coefficient, perform secondary correction on the time difference data, and fuse them to obtain the final interferometric arrival time difference; The calculation module is used to calculate the ultrasonic speed in the target area based on the time difference of arrival of the final interference.

[0018] Thirdly, embodiments of this application provide an electronic device, including a memory and a processor, wherein the memory stores program code that can run on the processor, and when the program code is executed by the processor, it implements a method for measuring the ultrasonic velocity of a concrete structure as described in any embodiment of the first aspect.

[0019] Fourthly, embodiments of this application provide a computer storage medium storing one or more programs, which can be executed by an electronic device as described in the third aspect to implement a method for measuring the ultrasonic velocity of concrete structures as described in any embodiment of the first aspect.

[0020] The present invention provides a method, apparatus, equipment, and medium for measuring ultrasonic velocity in concrete structures, which has the following advantages compared with the prior art: This invention performs consistency verification by pairing signals within the same group and performing initial interference. This can eliminate invalid data caused by errors in the measuring device, system, or operation in advance, ensuring the reliability of the measurement data from the source and avoiding interference from invalid data in subsequent calculations.

[0021] This invention obtains multiple sets of initial arrival time difference data by first-wave interference of fully paired cross-correlation between signals from the intact region and the target region, thereby expanding the effective data sample size and reducing the impact of random errors in a single measurement.

[0022] This invention can accurately identify data deviations caused by noise interference by grouping and filtering the initial time difference dataset, and perform secondary correction based on the sorting of cross-correlation coefficients from largest to smallest, correcting the data deviations to a reasonable range, thus avoiding the accuracy loss problem caused by directly averaging the highly fluctuating time difference data in traditional methods.

[0023] Under unchanged operating conditions, this invention can effectively reduce the noise impact of the environment, measurement personnel, and system during the measurement process, stabilize the calculation results of the first-wave interferometry, and obtain high-precision ultrasonic velocity measurement results for concrete, providing an accurate basis for the health status evaluation and damage identification of concrete structures.

[0024] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0025] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0026] Figure 1 This diagram illustrates an exemplary method for measuring ultrasonic speeds in concrete structures, as proposed in one embodiment of the present invention. Figure 2 A comparison chart of exemplary application results of this application is shown; Figure 3 A structural block diagram of an ultrasonic velocity measuring device for concrete structures according to an embodiment of the present invention is shown. Figure 4 A structural block diagram of an electronic device for performing an ultrasonic velocity measurement method for a concrete structure according to an embodiment of this application is shown. Figure 5 This application illustrates a computer-readable storage medium for storing or carrying a method for measuring the ultrasonic velocity of a concrete structure according to an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0028] In existing technologies, due to the influence of noise generated by the environment, measuring personnel, and the system, the first-wave interferometry method will produce large errors in multiple measurements during practical applications, causing the above ratio to fluctuate greatly. At this time, directly averaging the measurement results will seriously lose measurement accuracy.

[0029] The present invention provides a method for measuring ultrasonic velocity in concrete structures. By verifying the consistency of signals within the same group, performing cross-group full-pair cross-correlation interference, and correcting and fusing time difference data based on cross-correlation coefficient sorting, the method effectively reduces noise interference, stabilizes measurement results, and improves the measurement accuracy of ultrasonic velocity in concrete.

[0030] The following describes an application scenario of the ultrasonic velocity measurement method for concrete structures provided by an embodiment of the present invention: Please see Figure 1 , Figure 1 This is a schematic flowchart of an ultrasonic velocity measurement method for concrete structures provided in an embodiment of the present invention. In this embodiment, an ultrasonic velocity measurement method for concrete structures can be applied to, for example... Figure 2 The ultrasonic velocity measuring device 300 for concrete structures shown is neutralizing Figure 3 In the electronic device 200 shown, the following is specifically for... Figure 1 The process is described in detail below. A method for measuring ultrasonic velocity in concrete structures may include steps S110 to S150.

[0031] S110: Collect multiple sets of ultrasonic received signals from the intact area of ​​the concrete structure with known wave velocity and the target area with the wave velocity to be measured, respectively, and obtain two sets of signals.

[0032] In this embodiment, it is specifically applied to the acoustic monitoring of beam stress state near the foundation surface of a concrete dam. By measuring the ultrasonic velocity in the damaged area near the foundation surface of the concrete dam, it provides a basis for structural health assessment.

[0033] In some embodiments, ultrasonic signals are repeatedly acquired. Before acquiring ultrasonic signals, ultrasonic excitation sources and receiving sensors are respectively deployed in the intact area and the target area. The straight-line distance between the excitation source and the receiving sensor in the two areas is measured respectively, and the period of the excitation signal and the signal sampling interval are calibrated.

[0034] In this embodiment, on the concrete dam structure, an intact area with known wave velocity is selected as the reference area, and a damaged area with the wave velocity to be measured is selected as the target monitoring area. An ultrasonic excitation source and a signal receiving sensor are arranged in the intact area to accurately measure the straight-line distance between the excitation source and the receiving sensor. The known ultrasonic velocity in the intact region is ; Arrange ultrasonic excitation sources and signal receiving sensors of the same specifications in the target area, and accurately measure the straight-line distance between the excitation source and the receiving sensor. The excitation frequency of the calibrated excitation source is... The period of the excitation signal is... The sampling interval of the signal acquisition system is . S120: Perform the first-wave interference of pairwise combinations of signals within the same group on the two signal sets to complete the signal consistency check.

[0035] S130: Pair each signal in the intact region signal set with each signal in the target region signal set, perform cross-correlation first-wave interferometry on each pair of paired signals, and obtain the initial time difference of arrival dataset.

[0036] S140: Group and filter the initial time difference dataset, sort the time difference data based on cross-correlation coefficients, perform secondary correction on the deviated time difference data, and fuse them to obtain the final interferometric arrival time difference.

[0037] S150: Calculate the ultrasonic velocity in the target area based on the time difference of arrival of the final interference.

[0038] In some embodiments, signal bandpass filtering preprocessing is performed. The ultrasonic received signals of the intact region and the target region are acquired repeatedly n times using the same excitation and acquisition parameters, where n is a positive integer greater than or equal to 3, thereby obtaining the signal set of the intact region and the signal set of the target region.

[0039] In this embodiment, an ultrasonic signal is excited by an excitation source, and the received signal is simultaneously acquired by a receiving sensor through an acquisition system. The exact same excitation and acquisition parameters are used for both the intact region and the target region to complete the acquisition process. Repeated measurements and signal acquisition Take a positive integer greater than or equal to 3, where the values ​​collected from intact regions are included. The group of signals is denoted as the intact region signal set. j=1,2,... ; Data collected from the target area The group of signals is denoted as the target area signal set. , j=1,2,...n.

[0040] In some embodiments, all acquired ultrasonic received signals are first preprocessed by bandpass filtering, with the passband of the bandpass filter set centered on the excitation frequency of the excitation source.

[0041] In this embodiment, the signal set of the intact region and target area signal set All signals are subjected to bandpass filtering to remove environmental and system noise from the acquisition process. The passband range of the bandpass filter is set to... ,in The bandwidth adjustment factor is less than 1 to ensure that the filtered signal retains the effective components of the excitation frequency and suppresses out-of-band noise interference.

[0042] In some embodiments, a signal consistency check is performed within the same group. The criteria for signal consistency check are: the arrival time difference obtained by the first wave interference of any pair of paired signals within the same group is less than a preset sampling interval multiple threshold; if the criteria are not met, the signal is re-acquired until the requirements are met.

[0043] In this embodiment, the filtered intact region signal set Perform the first-wave interference by pairing signals within the same group: that is... respectively with , ... To carry out the first wave of intervention, respectively with , ... Perform the first wave of interference, and so on, to complete the pairwise interference of all signals within the same group, obtaining the time difference of arrival for each pair of signals. Similarly, for the filtered target region signal set... Perform first-wave interference by pairing signals within the same group to obtain the interference arrival time difference for each pair of signals. Set the criteria for consistency verification: all < And all < ,in The error coefficient is less than or equal to 3. If the above judgment criteria are met, it indicates that the signals in the same group are in good consistency and there are no errors in the measuring device, system, and operation, and the subsequent steps can be carried out; if the judgment criteria are not met, the connection of the measuring device and the parameter settings of the acquisition system should be checked, and after eliminating the erroneous operation in the measurement process, the signal acquisition should be carried out again until the consistency verification requirements are met.

[0044] In some embodiments, cross-group fully paired cross-correlation first-wave interference is performed. The execution process of cross-correlation first-wave interference includes: An interference window of fixed length is set on the time axis. The time axis position of the intact region signal in the paired signal is fixed. The signal in the interference window of the target region signal is moved along the time axis. The cross-correlation coefficient of the two signals is calculated at different moving distances. The moving distance corresponding to the maximum value of the cross-correlation coefficient is taken as the initial arrival time difference of the paired signals.

[0045] In this embodiment, the intact region signal set Each signal within the target region is associated with a specific signal set. Each signal within is paired up, that is, A1 is paired with B1, B2, ... Bn respectively, A2 is paired with B1, B2, ... Bn respectively, and so on, to complete the full cross pairing of the two sets of signals, resulting in a total of n×n pairs of paired signals.

[0046] For each pair of paired signals, perform cross-correlation first-wave interference, the specific process of which is as follows: Determine the length L of the interference window and the center point of the interference window on the time axis. The interference window covers the range of the first wave packet of the ultrasonic signal, ensuring effective extraction of the first wave signal; The intact region signal in the fixed paired signal on the time axis The target region signal remains stationary while moving along the time axis. The signal within the corresponding interference window is used to calculate different movement distances. Below, the cross-correlation coefficients of signals within the two windows. ; For all the calculated cross-correlation coefficients Sort the data and take the movement distance corresponding to the maximum cross-correlation coefficient. , as the initial arrival time difference of the paired signals. , where i is the number of the intact area signal and j is the number of the target area signal; After completing the interferometry calculations for all paired signals, all initial time differences of arrival (ITAs) are summarized to construct an IATA dataset. .

[0047] In some embodiments, the initial time difference of arrival dataset is subjected to grouping, secondary correction, and data fusion. The specific process is as follows: Group filtering: using the first signal from the intact region The first signal in the target area The initial time difference of arrival obtained by paired interferometry is the reference value. Using the half-cycle of the excitation signal, 0.5T, as a threshold, the initial time difference dataset... All data is divided into two groups: Group I is the compliance group, which includes all groups that meet the requirements. Time difference data; Group II is the deviation group, containing all those that meet the criteria. Time difference data.

[0048] Calculate the average value for each compliance group. The average value of the deviation group and the overall average value of the initial time difference dataset. .

[0049] Group to be corrected: Comparison and The groups with the larger absolute value of the difference are selected as the groups to be corrected.

[0050] Secondary correction: For each time difference data point within the correction group Retrieve its corresponding pairing signal and The cross-correlation coefficient calculation results are then used to search for the arrival time differences corresponding to the peak values ​​of the cross-correlation coefficients, in descending order of cross-correlation coefficient. , obtained by search Replace the original Until the replaced time difference data meets the requirements. Until the data can be categorized into the compliance group, complete the correction of all data in the group to be corrected.

[0051] Final time difference calculation: After replacing all the data to be corrected, the updated time difference dataset is obtained. The arithmetic mean of the updated time difference dataset is then calculated. The arithmetic mean of this value is taken as the final interferometric arrival time difference. .

[0052] Will Substitute into the equation The wave velocity at the damaged site can then be calculated. .

[0053] in, The straight-line distance between the excitation source and the receiving sensor within the intact area, For the known ultrasonic speeds in the intact region, c1 represents the straight-line distance between the excitation source and the receiving sensor within the target area, and c2 represents the speed of the ultrasonic wave to be measured within the target area. The time difference for the final intervention to arrive.

[0054] Taking acoustic monitoring of beam stress state near the foundation surface of a concrete dam as an example: The following steps are used: S1. Wave velocity is known on the concrete structure. An ultrasonic excitation source and a signal receiving sensor are placed in an intact location to measure the straight-line distance between the excitation source and the signal source. In the unknown wave speed The same ultrasonic excitation source and signal receiving sensor were placed at the damaged site to measure the straight-line distance between the excitation source and the signal source. The excitation frequency of the excitation source is The period of the excitation signal is... The sampling interval of the signal is .

[0055] S2. An ultrasonic signal is excited by a signal source, and the received signal is acquired by a receiving sensor through an acquisition system. Measurements are then taken and recorded. Secondary signal. Among them, the signal from intact parts... The signal at the site of injury is recorded as , .

[0056] S3, for signal and Perform bandpass filtering, passing through the interval of ,in The coefficient is less than 1.

[0057] S4. Using the traditional first-wave interferometry method, in the signal... Interference between them, that is and , ... Interference separately, and , ... By interfering separately, and so on, the interference results of these signals should be... < , Generally, the coefficient is less than 2 or 3; similarly, in the signal... There should be mutual interference between them. < If the above conditions are not met, the measuring device and system should be checked, and the measurement should be repeated after eliminating any errors in the measurement process until the above conditions are met.

[0058] S5, in signal and signal Interference between them, that is and , ... Interference separately, and , ... Interference is performed separately, and so on. The results of these interference signals are denoted as follows: , Indicates the number of signal A. This indicates the number of signal B.

[0059] Data fusion and calculation are performed as follows: : S51. Determine the length of the interference window on the time axis. Center point of the interference window

[0060] S52, Fix the signal on the time axis stationary, moving signal For the signals in the corresponding windows, calculate the cross-correlation coefficient between them, assuming the movement distance... The corresponding cross-correlation coefficient .right Sort and record them. First, sort and record them. The maximum value corresponding to Set as .

[0061] S53, For all Find the average At the same time The process was divided into two groups, Group I Group II In the formula, express and The interference results were analyzed, and the average values ​​of the two groups were calculated respectively. and .

[0062] S54, Comparison and We take the larger of the values ​​and operate on it. Let's assume here that... For the larger group, each in the group The corresponding and Search in descending order. and its corresponding ,use replace until Can be classified as This group.

[0063] S55, for the updated Recalculate the average This value is used as the interference result of the two sets of signals, A and B.

[0064] S6, will Substitute into the equation The wave velocity at the damaged site can then be calculated. .

[0065] The ultrasonic velocity measurement method for concrete structures according to the present invention yields the following results after application: Figure 2 ,from Figure 2 As can be seen, this invention is used to compare the measurement results of intact sites with known wave velocities and damaged sites with unknown wave velocities, calculate the wave velocity of the damaged sites, and thus provide a basis for structural health assessment. In practice, by cross-interfering the measurement results of intact and damaged sites, and by sorting and classifying the cross-correlation analysis results, data fusion is achieved, thereby correcting the problem of excessive differences in interference results caused by measurement error factors.

[0066] Please see Figure 3 , Figure 3 This invention provides a structural block diagram of an ultrasonic velocity measuring device 300 for concrete structures. The device includes: an acquisition module 310, a consistency verification module 320, a first-wave interference module 330, a screening and correction module 340, and a calculation module 350, wherein: The acquisition module 310 is used to acquire multiple sets of ultrasonic received signals from the intact area of ​​the concrete structure with known wave velocity and the target area with the wave velocity to be measured, respectively, and obtain two sets of signal sets. The consistency verification module 320 is used to perform the first wave interference of pairwise pairing of signals within the same group on the two sets of signals to complete the signal consistency verification. The first-wave interference module 330 is used to pair each signal in the intact region signal set with each signal in the target region signal set, and perform cross-correlation first-wave interference on each pair of paired signals to obtain the initial time difference of arrival dataset. The filtering and correction module 340 is used to group and filter the initial time difference dataset, perform secondary correction on the deviated time difference data based on the cross-correlation coefficient, and fuse them to obtain the final interferometric arrival time difference.

[0067] The calculation module 350 is used to calculate the ultrasonic velocity in the target area based on the time difference of arrival of the final interference.

[0068] It should be noted that the device embodiments in this invention correspond to the aforementioned method embodiments. The specific principles in the device embodiments can be found in the content of the aforementioned method embodiments, and will not be repeated here.

[0069] In the several embodiments provided in this example, the coupling between modules can be electrical, mechanical, or other forms of coupling.

[0070] Furthermore, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0071] Please see Figure 4 , Figure 4 The present application provides a structural block diagram of an electronic device 200 that can perform the above-described ultrasonic velocity measurement method for concrete structures. The electronic device 200 may be a smartphone, tablet computer, computer, or portable computer.

[0072] The electronic device 200 also includes a processor 202 and a memory 204. The memory 204 stores programs that can execute the contents of the foregoing embodiments, and the processor 202 can execute the programs stored in the memory 204.

[0073] The processor 202 may include one or more cores for data processing and message matrix units. The processor 202 connects to various parts within the electronic device 200 using various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 204, and by calling data stored in the memory 204. Optionally, the processor 202 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 202 may integrate one or more of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem / decoder. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem / decoder handles wireless communication. It is understood that the modem / decoder may also be implemented separately as a communication chip, without being integrated into the processor.

[0074] Memory 204 may include random access memory (RAM) or read-only memory (ROM). Memory 204 can be used to store instructions, programs, code, code sets, or instruction sets. Memory 204 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (e.g., instructions for a user to obtain random numbers), instructions for implementing the various method embodiments described below, etc. The data storage area may also store data (e.g., random numbers) created by the terminal during use.

[0075] Electronic device 200 may also include a network module and a screen. The network module is used to receive and transmit electromagnetic waves, converting electromagnetic waves into electrical signals, thereby enabling communication with communication networks or other devices, such as audio playback devices. The network module may include various existing circuit elements used to perform these functions, such as antennas, radio frequency transceivers, digital signal processors, encryption / decryption chips, SIM cards, memory, etc. The network module can communicate with various networks such as the Internet, corporate intranets, and wireless networks, or communicate with other devices via wireless networks. The aforementioned wireless networks may include cellular telephone networks, wireless local area networks, or metropolitan area networks. The screen can display interface content and facilitate data interaction.

[0076] Please refer to Figure 5 , Figure 5 This diagram illustrates a structural block diagram of a computer-readable storage medium according to an embodiment of this application. The computer-readable storage medium 400 stores program code 410, which can be called by a processor to execute the methods described in the above method embodiments.

[0077] The computer-readable storage medium 400 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium includes a non-transitory computer-readable storage medium. The computer-readable storage medium 400 has storage space for program code 410 that performs any of the method steps described above. This program code 410 can be read from or written to one or more computer program products. The program code 410 may be compressed, for example, in a suitable form.

[0078] This application also provides a computer program product or computer program that includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform a method for measuring the ultrasonic velocity of concrete structures as described in the various optional implementations above.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring ultrasonic velocity in concrete structures, characterized in that, An ultrasonic excitation source and receiving sensor are installed on the surface of a concrete structure to collect ultrasonic signals. The propagation time difference is calculated using first-wave interferometry to determine the ultrasonic velocity. The method includes: Multiple sets of ultrasonic received signals were collected from the intact area of ​​the concrete structure with known wave velocity and the target area with the wave velocity to be measured, respectively, and two sets of signal sets were obtained accordingly. Perform first-wave interference on each pair of signals within the same group for the two signal sets to complete the signal consistency verification. Each signal in the intact region signal set is paired with each signal in the target region signal set. Cross-correlation first-wave interferometry is performed on each pair of paired signals to obtain the initial time difference of arrival dataset. The initial time difference dataset is grouped and filtered, and the deviation time difference data is corrected a second time based on the cross-correlation coefficient. The final interferometric arrival time difference is obtained by fusion. The ultrasonic velocity in the target area is calculated based on the time difference of arrival of the final interference.

2. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, Before acquiring ultrasonic signals, ultrasonic excitation sources and receiving sensors are deployed in the intact area and the target area, respectively. The straight-line distance between the excitation source and the receiving sensor in the two areas is measured to calibrate the period of the excitation signal and the signal sampling interval.

3. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, The ultrasound received signals from both the intact region and the target region are acquired n times using the same excitation and acquisition parameters, where n is a positive integer greater than or equal to 3, resulting in the signal sets from the intact region and the target region, respectively.

4. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, All acquired ultrasonic received signals are first preprocessed by bandpass filtering, with the passband range of the bandpass filter set centered on the excitation frequency of the excitation source.

5. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, The criteria for signal consistency verification are as follows: the arrival time difference obtained by the first wave interference of any pair of paired signals in the same group is less than the preset sampling interval multiple threshold; if the criteria are not met, the signal is re-acquired until the requirements are met.

6. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, The execution process of the first wave of cross-correlation interference includes: An interference window of fixed length is set on the time axis. The time axis position of the intact region signal in the paired signal is fixed. The signal in the interference window of the target region signal is moved along the time axis. The cross-correlation coefficient of the two signals is calculated at different moving distances. The moving distance corresponding to the maximum value of the cross-correlation coefficient is taken as the initial arrival time difference of the paired signals.

7. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, The rules for group filtering include: Using the arrival time difference obtained by pairing and interfering the first signal from the intact region with the first signal from the target region as the baseline value, and using half the period of the excitation signal as the threshold, the initial time difference dataset is divided into two groups: For the compliant group whose absolute difference from the benchmark value is less than half a period, and the deviation group whose absolute difference from the benchmark value is greater than half a period, calculate the average of the two groups and the overall average of the initial time difference dataset.

8. The ultrasonic velocity measurement method for concrete structures according to claim 7, characterized in that, The steps of the secondary correction include: Compare the absolute values ​​of the differences between the mean of the compliant group, the mean of the deviation group, and the overall mean of the dataset, and select the group with the larger absolute value of the difference as the group to be corrected; For each time difference data pair corresponding to a correction group, the time difference corresponding to the second peak value is searched sequentially in descending order of cross-correlation coefficient. The original time difference data is replaced with the searched time difference until the replaced time difference data can be classified into the compliance group.

9. The ultrasonic velocity measurement method for concrete structures according to claim 8, characterized in that, After replacing all the data to be corrected, the arithmetic mean of the updated time difference dataset is calculated, and the arithmetic mean is used as the final time difference of arrival for the interferometry.

10. The ultrasonic velocity measurement method for concrete structures according to claim 1, characterized in that, The ultrasonic velocity in the target region is solved by the equation for calculating the velocity of the first interferometric wave. The expression of the equation for calculating the velocity of the first interferometric wave is as follows: In the formula, The straight-line distance between the excitation source and the receiving sensor within the intact area, For the known ultrasonic speeds in the intact region, c1 represents the straight-line distance between the excitation source and the receiving sensor within the target area, c2 represents the speed of the ultrasonic wave to be measured in the target area, and Δt represents the time difference of arrival of the final interference.

Images