Frequency mixing method and device for eddy current detection, electronic equipment and storage medium

Abstract

The invention relates to a frequency mixing method and device for eddy current detection, electronic equipment and a storage medium, which are used for improving the detection efficiency of eddy current detection. The method comprises the following steps: acquiring manual calibration pipe data, wherein the manual calibration pipe data comprises eddy current signal data of a plurality of different channels; screening out a plurality of pieces of pipeline area signal data from all the eddy current signal data; performing signal analysis on the signal data of each pipeline region one by one, and extracting signal data of a candidate region of the support plate; identifying target support plate signal data from the support plate candidate region signal data by using a sliding window detection method; calculating a mixing factor according to the target support plate signal data; and performing frequency mixing processing on target test tube data by using the frequency mixing factor to obtain target frequency mixing signal data.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive testing, and in particular to a frequency mixing method, device, electronic equipment and storage medium for eddy current testing. Background Art

[0002] During the operation of nuclear power plants, the health of condenser heat transfer tubes is crucial to the safety and reliability of the equipment. Eddy current testing, as an efficient non-destructive testing technology, is widely used in metal pipe defect detection and is also one of the important detection methods for condenser heat transfer tubes in nuclear power plants. However, in actual applications, eddy current detection signals are often interfered by non-pipe structures such as support plates, making it difficult to accurately identify defects in these areas, increasing the risk of missed detection and misjudgment.

[0003] At present, in order to suppress the influence of the support plate signal on the eddy current testing results, it is usually necessary to draw a map of the test data in a specific analysis software, and manually identify and select the support plate area in the map by naked eyes, and then the software performs mixed frequency calculation based on the selection result to highlight the defect signal. However, this processing method requires manual labor to spend a lot of time to identify the support plate area in the complex map, which will reduce the detection efficiency of eddy current testing. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a frequency mixing method, device, electronic equipment and storage medium for eddy current detection.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide a frequency mixing method for eddy current detection, comprising:

[0006] S101, obtaining artificial calibration tube data, wherein the artificial calibration tube data contains eddy current signal data of multiple different channels;

[0007] S102, selecting a plurality of pipeline area signal data from all eddy current signal data;

[0008] S103, performing signal analysis on the signal data of each pipeline area one by one, and extracting the signal data of the candidate support plate area;

[0009] S104, identifying target support plate signal data from the support plate candidate area signal data using a sliding window detection method;

[0010] S105, calculating a mixing factor according to the target support plate signal data;

[0011] S106 , performing mixing processing on the target test tube data using the mixing factor to obtain target mixing signal data.

[0012] Preferably, the step S104 includes:

[0013] Setting a sliding window that slides according to a preset rule in the signal data of the candidate region of the support plate;

[0014] Acquire signal data at each different position where the sliding window stops;

[0015] Performing fluctuation characteristic statistics on the signal data within the sliding window;

[0016] The signal data in the sliding window whose fluctuation characteristic is greater than a first preset threshold is determined as the target support plate signal data.

[0017] Preferably, the step S102 includes:

[0018] Subtract the maximum value and the minimum value of each eddy current signal data within a preset window range to obtain the signal fluctuation amplitude of the corresponding eddy current signal data;

[0019] The eddy current signal data whose signal fluctuation amplitude is less than a second preset threshold is determined as pipeline area signal data.

[0020] Preferably, the step S105 includes:

[0021] Performing rotation correction on the target support plate signal data so that the high-frequency signal and the low-frequency signal in the target support plate signal data are aligned in phase;

[0022] Performing amplitude scaling on the rotation-corrected target support plate signal data so that the amplitudes of the high-frequency signal and the low-frequency signal are aligned;

[0023] The residual between the high-frequency signal and the low-frequency signal is minimized by using the least square method to obtain a mixing factor.

[0024] Preferably, step 106 includes:

[0025] The product of the low-frequency signal in the target test tube signal data and the mixing factor is calculated, and the high-frequency signal in the target test tube signal data is subtracted from the product to obtain the target mixing signal data.

[0026] Preferably, before step 104, the frequency mixing method further includes:

[0027] The signal data of the candidate region of the support plate is preprocessed, and the preprocessing includes filtering and smoothing.

[0028] Preferably, after step 104, the frequency mixing method further comprises:

[0029] Performing continuity detection on the target support plate signal data;

[0030] The validity of the target support plate signal data is determined based on the continuity detection result.

[0031] The present invention also provides a frequency mixing device for eddy current detection, comprising:

[0032] An acquisition unit, used for acquiring artificial calibration tube data, wherein the artificial calibration tube data contains eddy current signal data of multiple different channels;

[0033] A screening unit, used for screening out a number of pipeline area signal data from all eddy current signal data;

[0034] An extraction unit, used to analyze the signal data of each pipeline area one by one, and extract the signal data of the candidate area of ​​the support plate;

[0035] An identification unit, used for identifying the target support plate signal data from the support plate candidate area signal data by using a sliding window detection method;

[0036] A calculation unit, used for calculating a mixing factor according to the target support plate signal data;

[0037] The mixing unit is used to perform mixing processing on the target test tube data using the mixing factor to obtain target mixing signal data.

[0038] The present invention also provides an electronic device, comprising:

[0039] CPU, memory, input and output interfaces, wired or wireless network interfaces, and power supply;

[0040] The memory is a short-term storage memory or a persistent storage memory;

[0041] The central processing unit is configured to communicate with the memory and execute instructions in the memory to perform the frequency mixing method of eddy current detection.

[0042] The present invention also provides a computer-readable storage medium, comprising instructions, which, when executed on a computer, enable the computer to execute the above-mentioned frequency mixing method for eddy current detection.

[0043] The implementation of the present invention has the following beneficial effects: the pipeline area signal data is screened out from the eddy current signal data to eliminate the connection area between the test tube and the calibration tube. Then the signal data corresponding to the pipeline area belonging to the support plate candidate area is used as the support plate candidate area signal data. Then the sliding window detection method is used to find the position of the target support plate from the support plate candidate area to obtain the target support plate signal data. Finally, the target support plate signal data is used for mixing processing to suppress the interference of the support plate signal during the eddy current detection process. In this way, before the target test tube data is analyzed, the target support plate signal data can be obtained according to the manual calibration tube data, and the mixing factor can be obtained according to the target support plate signal data, and then the target test tube data can be mixed using the mixing factor to reduce the interference of the support plate signal on the target test tube data. It is no longer necessary to manually identify the support plate area signal to reduce the time spent by humans in the identification process, thereby improving the detection efficiency of eddy current detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0045] Figure 1 It is a schematic diagram of an embodiment of a frequency mixing method for eddy current detection of the present invention;

[0046] Figure 2-1 and Figure 2-2 is a schematic diagram of another embodiment of the frequency mixing method for eddy current detection of the present invention;

[0047] Figure 3 It is a schematic diagram of an embodiment of a frequency mixing device for eddy current detection of the present invention;

[0048] Figure 4 It is a schematic diagram of an implementation of the electronic device of the present invention. DETAILED DESCRIPTION

[0049] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. Features defined as "first", "second", "third", etc. may explicitly or implicitly include one or more of the features. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0051] The present invention provides a frequency mixing method, device, electronic equipment and storage medium for eddy current detection, which are used to improve the detection efficiency of eddy current detection.

[0052] The method provided by the present invention is applied to a system, a server or a terminal with logic analysis and processing capabilities for execution and implementation. The embodiment of the present invention is described by taking a system as an example. Figure 1 As shown, an embodiment of the frequency mixing method of eddy current detection of the present invention includes:

[0053] S101, obtaining artificial calibration tube data, where the artificial calibration tube data contains eddy current signal data of multiple different channels;

[0054] In this embodiment, the system reads the manual calibration tube data from the raw data file generated by the eddy current detection device, and the manual calibration tube data includes calibration tube data and test tube data. Among them, the calibration tube data refers to the data generated by the eddy current detection device after detecting the calibration tube. The calibration tube refers to a section of pipe with the same specifications and materials as the pipe to be tested, on which several standard defects are processed to serve as a reference for detecting the test tube and a sample tube for verifying the effectiveness of the detection system. The test tube data refers to the data generated by the eddy current detection device after detecting the pipe to be tested.

[0055] Specifically, the manual calibration tube data contains eddy current signal data of multiple channels, including differential channels and absolute channels. Each channel has different components (such as horizontal components and vertical components) and signals of different frequencies (such as 550kHz differential channel 1 and 100kHz differential channel 5) for detecting defects of different depths and sizes. In addition, the manual calibration tube data can also include auxiliary information such as probe model, sampling rate, timestamp, synchronization header and checksum. During the data reading process, the system parses the binary raw data file into a structured data format, extracts the eddy current signal data of each channel, and uses the synchronization header to verify the integrity of this part of the eddy current signal data to improve the reliability of subsequent signal analysis and processing.

[0056] S102, selecting a plurality of pipeline area signal data from all eddy current signal data;

[0057] In this embodiment, since the manual calibration tube data includes calibration tube data and test tube data, and the calibration tube and the test tube are two different pipes connected together, there will be a seam between the two, and the seam area will also generate detection data during detection, so it is necessary to first remove the detection data of the seam area. Specifically, when performing signal acquisition, the inlet and outlet areas of the pipeline (i.e., the seam area between different pipelines) will generate air signals. Since the air signal fluctuates violently, the signal data in the seam area can be called non-stationary area signal data. The signal data inside the pipeline is relatively stable, so the signal data inside the pipeline can also be called stable area signal data. Furthermore, by distinguishing the signal fluctuations of different eddy current signal data, different eddy current signal data can be divided into stable area signal data and non-stationary area signal data. Finally, the acquired stable area signal data can be determined as pipeline area signal data, and the acquired non-stationary area signal data can be determined as seam area signal data. This part of the pipeline area signal data contains calibration tube area signal data and test tube area signal data.

[0058] S103, performing signal analysis on the signal data of each pipeline area one by one, and extracting the signal data of the candidate support plate area;

[0059] In this embodiment, after the system obtains the pipeline area signal data, it is necessary to determine whether each pipeline area signal data belongs to the support plate candidate area. If a pipeline area signal data belongs to the support plate candidate area, it means that the pipeline area signal data is the signal data of the test tube. If a pipeline area signal data does not belong to the support plate candidate area, it means that the pipeline area signal data is the signal data of the calibration tube. Specifically, each pipeline area signal data can be smoothed first to reduce the random fluctuation of the signal. Then the pipeline area signal data after smoothing is pruned to reduce redundant signals. Finally, the pipeline area signal data after smoothing and pruned is peak detected, and the pipeline area signal data is judged whether it is the support plate candidate area signal data according to the peak detection result. It is worth mentioning that after obtaining the support plate candidate area signal data, this part of the support plate candidate area signal data can be further adjusted and optimized, for example: this part of the support plate candidate area signal data is smoothed again to eliminate possible noise and interference.

[0060] S104, identifying the target support plate signal data from the support plate candidate area signal data using a sliding window detection method;

[0061] In this embodiment, since the support plate candidate area signal data contains signal data of multiple different positions such as the pipeline inner wall area, the pipeline outer wall area and the support plate area, the sliding window detection method can be used to perform signal analysis on each area position in the support plate candidate area signal data one by one to identify the target support plate signal data.

[0062] S105, calculating a mixing factor according to the target support plate signal data;

[0063] In this embodiment, after acquiring the target support plate signal data, the system first acquires the eddy current signal data of different frequencies in the target support plate signal data, and then calculates the mixing factor according to the residual between the eddy current signal data of different frequencies. The specific calculation process will be described in subsequent embodiments.

[0064] S106 , performing mixing processing on the target test tube data using the mixing factor to obtain target mixed signal data.

[0065] Specifically, the target test tube data is the test data generated by the eddy current testing equipment for the test tubes of the same batch, which are the test tubes of the same specification and material as the calibration tubes and are in the same testing environment. The target test tube data is mixed with the mixing factor to eliminate the support plate signal data in the target test tube data.

[0066] In this embodiment, the system filters out the pipeline area signal data from the eddy current signal data to eliminate the connection area between the test tube and the calibration tube. Then the signal data corresponding to the pipeline area belonging to the support plate candidate area is used as the support plate candidate area signal data. Then the sliding window detection method is used to find the position of the target support plate from the support plate candidate area to obtain the target support plate signal data. Finally, the target support plate signal data is used for mixing processing to suppress the interference of the support plate signal during the eddy current detection process. In this way, before the target test tube data is analyzed, the target support plate signal data can be obtained according to the manual calibration tube data, and the mixing factor can be obtained according to the target support plate signal data, and then the target test tube data can be mixed using the mixing factor to reduce the interference of the support plate signal on the target test tube data. And it is no longer necessary to manually identify the support plate area signal to reduce the time spent by humans in the identification process, thereby improving the detection efficiency of eddy current detection.

[0067] like Figure 2-1 and Figure 2-2 As shown, another embodiment of the frequency mixing method of eddy current detection of the present invention includes:

[0068] S201, obtaining artificial calibration tube data, where the artificial calibration tube data contains eddy current signal data of multiple different channels;

[0069] Step S201 in this embodiment is similar to the above Figure 1 Step 101 in the illustrated embodiment is similar and will not be described in detail here.

[0070] S202, subtracting the maximum value and the minimum value of each eddy current signal data within a preset window range to obtain a signal fluctuation amplitude of the corresponding eddy current signal data;

[0071] S203, determining that the eddy current signal data whose signal fluctuation amplitude is less than a second preset threshold value is pipeline area signal data;

[0072] Optionally, in this embodiment, the system first selects the eddy current signal data of the horizontal component and the vertical component in all signal channels, and then analyzes the fluctuation of each eddy current signal data at different positions. Specifically, a preset window can be set at different positions, and then the maximum and minimum values ​​of each eddy current signal data within the preset window range are obtained, and the difference between the maximum and the minimum values ​​is calculated to obtain the signal fluctuation amplitude of each eddy current signal data within the preset window range. When the signal fluctuation amplitude is less than the second preset threshold, it means that the eddy current signal data corresponding to the signal fluctuation amplitude is in a stable area, and at this time, it can be determined that the eddy current signal data is pipeline area signal data. When the signal fluctuation amplitude is greater than or equal to the second preset threshold, it means that the eddy current signal data corresponding to the signal fluctuation amplitude is in an unstable area, and at this time, it can be determined that the eddy current signal data is non-pipeline area signal data.

[0073] S204, performing signal analysis on the signal data of each pipeline area one by one, and extracting the signal data of the candidate support plate area;

[0074] Step S204 in this embodiment is similar to the above Figure 1 Step 103 in the illustrated embodiment is similar and will not be described in detail here.

[0075] S205, preprocessing the signal data of the candidate region of the support plate, wherein the preprocessing includes filtering and smoothing;

[0076] S206, setting a sliding window that slides according to a preset rule in the signal data of the candidate region of the support plate;

[0077] S207, obtaining signal data where the sliding window stops at different positions;

[0078] S208, performing fluctuation characteristic statistics on the signal data in the sliding window;

[0079] S209, determining that the signal data in the sliding window whose fluctuation characteristics are greater than a first preset threshold value is the target support plate signal data;

[0080] Optionally, in this embodiment, before extracting the target support plate signal data from the signal data of the support plate candidate region, the signal data of the support plate candidate region may be preprocessed first. The preprocessing process may include filtering and smoothing. Among them, a low-pass filter may be used for filtering to eliminate high-frequency noise; a moving average algorithm may be used for smoothing to reduce the random fluctuation of the signal and make the signal more stable. Then, a sliding window is set for the preprocessed signal data of the support plate candidate region. The sliding window slides within the range of the signal data of the support plate candidate region according to a preset rule, and the fluctuation characteristics of the signal data of the support plate candidate region within the sliding window are statistically analyzed at each stop position of the sliding path, such as: average value, standard deviation, and range. Finally, the statistically analyzed fluctuation characteristics are compared with a first preset threshold. If the fluctuation characteristics are greater than the first preset threshold, the corresponding signal data of the support plate candidate region is determined as the target support plate signal data; if the fluctuation characteristics are less than or equal to the first preset threshold, the corresponding signal data of the support plate candidate region is determined as non-target support plate signal data. For example: the range of the signal data Q1 of the support plate candidate region within the sliding window staying at position A is R1, the range of the signal data Q2 of the support plate candidate region within the stop position B is R2, and the first preset threshold is T. Among them, R1>T and R2<T, then the signal data Q1 of the support plate candidate region can be determined as the target support plate signal data, and the signal data Q2 of the support plate candidate region is determined as non-target support plate signal data.

[0081] S210. Perform continuity detection on the target support plate signal data;

[0082] S211. Determine the validity of the target support plate signal data according to the continuity detection result;

[0083] Optionally, in this embodiment, after the system obtains the target support plate signal data, the continuity of the target support plate signal data may be detected. Among them, the continuity of the target support plate detection signal data may be determined by judging whether the length of the target support plate signal data meets the preset data point requirement. For example: the preset data point is 50 data points. When the length of the target support plate signal data is greater than 50 data points, it means that the target support plate signal data is valid; when the length of the target support plate signal data is less than 50 data points, it means that the target support plate signal data may be invalid data such as noise, and at this time, the target support plate signal data may be discarded.

[0084] S212. Perform rotation correction on the target support plate signal data so that the high-frequency signal and the low-frequency signal in the target support plate signal data are in phase alignment;

[0085] S213, performing amplitude scaling on the target support plate signal data after rotation correction so that the amplitudes of the high-frequency signal and the low-frequency signal are aligned;

[0086] S214, using the least square method to minimize the residual between the high-frequency signal and the low-frequency signal, and solving to obtain a mixing factor;

[0087] Optionally, in this embodiment, when calculating the mixing factor, the target support plate signal data can be first rotationally corrected. The specific process is: the low-frequency signal of the target support plate signal data is phase adjusted to align the phase with the high-frequency signal. Among them, by calculating the phase difference between the high-frequency signal and the low-frequency signal, the phase difference is eliminated to ensure that signals of different frequencies are compared under the same phase reference. Then, the target support plate signal data after rotation correction is amplitude scaled. The specific process is: by calculating the amplitude proportional coefficient, the low-frequency signal after rotation correction is amplitude scaled to eliminate the amplitude difference to ensure that the high-frequency signal and the low-frequency signal are at the same level in amplitude, which is convenient for subsequent mixing processing. Finally, the least squares method is used to minimize the residual between the high-frequency signal and the adjusted low-frequency signal. The specific process is: first, in the target support plate signal data area, the sum of squares of the residuals is constructed as the objective function:

[0088]

[0089] The objective function E(D) represents the degree of difference between the high frequency signal and the adjusted low frequency signal.

[0090] Then, the objective function E(D) is differentiated with respect to D, and the derivative is set to zero to solve the optimal mixing factor D:

[0091]

[0092] The solution is:

[0093]

[0094] The mixing factor is used in subsequent signal mixing processing to effectively suppress the interference signal of the support plate and highlight the actual defect signal of the pipeline.

[0095] S215, calculating the product of the low-frequency signal in the target test tube signal data and the mixing factor, and subtracting the high-frequency signal in the target test tube signal data from the product to obtain target mixing signal data.

[0096] Optionally, in this embodiment, the system performs mixing processing on the target test tube signal data according to the mixing factor and the corresponding mixing formula. The specific mixing formula is as follows:

[0097] Smix(n)=Shigh(n)-D×Slow(n)

[0098] Among them, S high (n) is the high frequency signal, S low (n) is the low-frequency signal after rotation correction and amplitude scaling, and D is the mixing factor. In this way, the target mixed signal data S obtained after mixing mix (n) Interference signals such as support plates can be effectively suppressed to facilitate identification of defect signals.

[0099] like Figure 3 As shown, an embodiment of the frequency mixing device for eddy current detection in the present invention includes:

[0100] An acquisition unit 301 is used to acquire artificial calibration tube data, where the artificial calibration tube data contains eddy current signal data of multiple different channels;

[0101] A screening unit 302 is used to screen out a number of pipeline area signal data from all eddy current signal data;

[0102] The extraction unit 303 is used to perform signal analysis on the signal data of each pipeline area one by one, and extract the signal data of the candidate support plate area;

[0103] The identification unit 304 is used to identify the target support plate signal data from the support plate candidate area signal data using a sliding window detection method;

[0104] A calculation unit 305, configured to calculate a mixing factor according to the target support plate signal data;

[0105] The mixing unit 306 is used to perform mixing processing on the target test tube data using the mixing factor to obtain target mixed signal data.

[0106] In this embodiment, the acquisition unit 301 acquires the artificial calibration tube data, which contains eddy current signal data of multiple different channels; the screening unit 302 screens out a number of pipeline area signal data from all eddy current signal data; the extraction unit 303 performs signal analysis on each pipeline area signal data one by one, and extracts the support plate candidate area signal data; the identification unit 304 uses the sliding window detection method to identify the target support plate signal data from the support plate candidate area signal data; the calculation unit 305 calculates the mixing factor according to the target support plate signal data; the mixing unit 306 uses the mixing factor to perform mixing processing on the target test tube data to obtain the target mixing signal data. In this way, before performing data analysis on the target test tube data, the target support plate signal data can be first obtained according to the artificial calibration tube data, and the mixing factor can be obtained according to the target support plate signal data, and then the mixing factor can be used to perform mixing processing on the target test tube data to reduce the interference of the support plate signal on the target test tube data. It is no longer necessary to manually identify the support plate area signal, so as to reduce the time spent by humans in the identification process, thereby improving the detection efficiency of eddy current detection.

[0107] like Figure 4 As shown, an embodiment of the electronic device in the present invention includes:

[0108] CPU 402, memory 401, input / output interface 403, wired or wireless network interface 404 and power supply 405;

[0109] The memory 401 is a temporary storage memory or a permanent storage memory;

[0110] The CPU 402 is configured to communicate with the memory 401 and execute the instructions in the memory 401 to perform the aforementioned Figure 1 , Figure 2-1 as well as Figure 2-2 Steps in the illustrated embodiment.

[0111] The present invention provides a computer-readable storage medium, including instructions, which, when executed on a computer, enable the computer to execute the aforementioned Figure 1 , Figure 2-1 as well as Figure 2-2 Steps in the illustrated embodiment.

[0112] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A frequency mixing method for eddy current detection, characterized in that: include: S101, obtaining artificial calibration tube data, wherein the artificial calibration tube data contains eddy current signal data of multiple different channels; S102, selecting a plurality of pipeline area signal data from all eddy current signal data; S103, performing signal analysis on the signal data of each pipeline area one by one, and extracting the signal data of the candidate support plate area; S104, identifying target support plate signal data from the support plate candidate region signal data using a sliding window detection method; S105, calculating a mixing factor according to the target support plate signal data; S106 , performing mixing processing on the target test tube data using the mixing factor to obtain target mixing signal data.

2. The frequency mixing method for eddy current detection according to claim 1, characterized in that: The step S104 includes: Setting a sliding window that slides according to a preset rule in the signal data of the candidate region of the support plate; Acquire signal data at each different position where the sliding window stops; Performing fluctuation characteristic statistics on the signal data within the sliding window; The signal data in the sliding window whose fluctuation characteristic is greater than a first preset threshold is determined as the target support plate signal data.

3. The frequency mixing method for eddy current detection according to claim 1, characterized in that: The step S102 includes: Subtract the maximum value and the minimum value of each eddy current signal data within a preset window range to obtain the signal fluctuation amplitude of the corresponding eddy current signal data; The eddy current signal data whose signal fluctuation amplitude is less than a second preset threshold is determined as pipeline area signal data.

4. The frequency mixing method for eddy current detection according to claim 1, characterized in that: The step S105 comprises: Performing rotation correction on the target support plate signal data so that the high-frequency signal and the low-frequency signal in the target support plate signal data are aligned in phase; Performing amplitude scaling on the rotation-corrected target support plate signal data so that the amplitudes of the high-frequency signal and the low-frequency signal are aligned; The residual between the high-frequency signal and the low-frequency signal is minimized by using the least square method to obtain a mixing factor.

5. The frequency mixing method for eddy current detection according to claim 1, characterized in that: The step 106 includes: The product of the low-frequency signal in the target test tube signal data and the mixing factor is calculated, and the high-frequency signal in the target test tube signal data is subtracted from the product to obtain the target mixing signal data.

6. The frequency mixing method for eddy current detection according to any one of claims 1 to 5, characterized in that: Before step 104, the frequency mixing method further includes: The signal data of the candidate region of the support plate is preprocessed, and the preprocessing includes filtering and smoothing.

7. The frequency mixing method for eddy current detection according to any one of claims 1 to 5, characterized in that: After step 104, the frequency mixing method further includes: Performing continuity detection on the target support plate signal data; The validity of the target support plate signal data is determined based on the continuity detection result.

8. A frequency mixing device for eddy current detection, characterized in that: include: An acquisition unit, used for acquiring artificial calibration tube data, wherein the artificial calibration tube data contains eddy current signal data of multiple different channels; A screening unit, used for screening out a number of pipeline area signal data from all eddy current signal data; An extraction unit, used to analyze the signal data of each pipeline area one by one, and extract the signal data of the candidate area of ​​the support plate; An identification unit, used for identifying the target support plate signal data from the support plate candidate area signal data by using a sliding window detection method; A calculation unit, used for calculating a mixing factor according to the target support plate signal data; The mixing unit is used to perform mixing processing on the target test tube data using the mixing factor to obtain target mixing signal data.

9. An electronic device, characterized in that: include: CPU, memory, input and output interfaces, wired or wireless network interfaces, and power supply; The memory is a short-term storage memory or a persistent storage memory; The central processing unit is configured to communicate with the memory and execute instructions in the memory to perform the frequency mixing method for eddy current detection according to any one of claims 1 to 7.

10. A computer-readable storage medium comprising instructions, which, when executed on a computer, enable the computer to execute the frequency mixing method for eddy current detection according to any one of claims 1 to 7.

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