Dam leakage automatic detection device based on high-frequency acoustic detection and detection method thereof

Abstract

The application discloses a dam leakage automatic detection equipment based on high-frequency acoustic detection and relates to the underwater detection field. The equipment comprises a transmitting transducer, a transmitting module, a receiving transducer, a receiving module, a main control module and an upper computer. The upper computer comprises a display control computer and display control software. The transmitting transducer and the receiving transducer are not designed to be combined for transmission and reception, but are designed to be separated, so that the receiving door setting is not needed, and the detection blind area range can be effectively reduced. The application also relates to a detection method of the dam leakage automatic detection equipment based on high-frequency acoustic detection.

Description

Technical Field

[0001] This invention relates to the field of underwater detection, and more specifically, to an automatic dam leakage detection device based on high-frequency acoustic detection. The invention also relates to a detection method for this automatic dam leakage detection device based on high-frequency acoustic detection. Background Technology

[0002] my country has numerous reservoirs and dams, and the number of high dams and large reservoirs ranks first in the world. With the aging of these structures and the occurrence of natural disasters, dams are developing problems such as cracks, seepage, and deformation. Among these, dam seepage, due to its highly concealed nature, dispersed locations, and significant hazards, has become the most important safety risk in reservoir dam operation. High dams and large reservoirs often lack the conditions for emptying, or emptying them would bring enormous economic, environmental, and social impacts. Therefore, effectively detecting deep-water seepage in dams is a crucial issue for ensuring the safe operation of these projects.

[0003] Existing leakage detection methods are mainly geophysical methods, which have large detection errors and cannot detect deep-water leaks. In recent years, underwater robot-based camera inspection has been widely used in the domestic and international water conservancy and hydropower industries due to its advantages such as large water depth detection and low safety risks. However, underwater camera inspection still mainly relies on manual observation, which has problems such as poor effect, low efficiency, large blind spots, and low accuracy in identifying underwater leaks and cracks.

[0004] Therefore, it is necessary to develop an automatic dam leakage detection device and its detection method based on high-frequency acoustic detection. Summary of the Invention

[0005] The primary objective of this invention is to overcome the shortcomings of the aforementioned background technology and to provide an automatic dam leakage detection device based on high-frequency acoustic detection.

[0006] The second objective of this invention is to provide a detection method for this automatic dam leakage detection device based on high-frequency acoustic detection.

[0007] To achieve the aforementioned first objective, the technical solution of the present invention is as follows: an automatic dam seepage detection device based on high-frequency acoustic detection, characterized in that: it includes a transmitting transducer, a transmitting module connected to the transmitting transducer, a receiving transducer, a receiving module connected to the receiving transducer, a main control module connected to the transmitting module and the receiving module, and a host computer connected to the main control module, wherein the host computer includes a display and control computer and display and control software.

[0008] In the above technical solution, the transmitting transducer and the receiving transducer are installed on the transducer compartment, and the transmitting module, the receiving module and the main control module are installed as a whole in the watertight electronic compartment.

[0009] In the above technical solution, the watertight electronic compartment communicates with the host computer via a data cable, and the watertight electronic compartment is connected to the transducer compartment via a transducer cable.

[0010] In the above technical solution, both the transducer compartment and the watertight electronics compartment are mounted on an underwater ROV, and the host computer is located on land or on a survey mother ship; the watertight electronics compartment is connected to the underwater ROV via a transducer cable, and the underwater ROV is connected to the host computer via an ROV umbilical cable.

[0011] In the above technical solution, the transmitting transducer realizes electroacoustic conversion, the receiving transducer realizes acoustic-electric conversion, the transmitting module is a power amplifier circuit to realize the power amplification of the transmitted signal; the receiving module realizes echo signal filtering, amplification and acquisition; the main control module realizes signal acquisition control, signal processing, network communication and high-frequency drive signal output; the host computer includes a display and control computer and display and control software, which realizes the functions of equipment status control, parameter setting, measurement result and status display and raw data storage.

[0012] To achieve the second objective mentioned above, the technical solution of the present invention is: a detection method for an automatic dam seepage detection device based on high-frequency acoustic detection, characterized by comprising the following steps:

[0013] Step 1: Using the work cycle as the basic working unit, the transmitting module continuously transmits N frames of signals in each work cycle, with a frame period of T. F The effective pulse width of each frame of signal is T0;

[0014] Each working cycle yields a set of instantaneous frequency sequences. After averaging the instantaneous frequency sequences over P consecutive working cycles, an effective flow velocity and bottom clearance data are calculated and updated in the chart window of the host computer's main interface. That is, the update rate of the data results is P working cycles.

[0015] The water flow velocity is calculated only for the water body near the dam face;

[0016] Step 2: After receiving a periodic signal, the receiving module first performs orthogonal transformation and low-pass filtering on the periodic signal to remove the harmonic components and obtain the difference frequency signal containing the Doppler frequency offset; then, the periodic signal is subjected to inter-frame conversion and inter-frame high-pass filtering to filter out interference signals near the zero frequency; then, the complex cross-covariance frequency measurement method is used to calculate the instantaneous frequency of the inter-frame signal point by point to obtain the instantaneous frequency sequence of the current period;

[0017] Then, the instantaneous frequency measurement sequence is processed by point-by-point moving average to obtain the instantaneous frequency sequence measurement result after moving average; when the number of cycles reaches the set value, the instantaneous frequency sequence measurement results of multiple cycles are averaged by cycle, and then the effective instantaneous frequency detection and water flow velocity calculation are performed.

[0018] Step 3: The specific processing steps for inter-frame conversion and inter-frame high-pass filtering are described as follows: Assuming N frames of data are transmitted, after orthogonal transformation and low-pass filtering, N frames of data can also be obtained. Take the first sampling point of the first frame to the Nth frame of data to form a set of data (N sampling points), perform high-pass filtering, and obtain the real part I of this set of data. d (i, 1) and the imaginary part Q d (i, 1), where i=1, 2...N;

[0019] Then, the data from the first frame to the second sampling point of the Nth frame are taken to form a set of data. This set of data is then high-pass filtered to remove the DC component, and the real part I of this set of data is obtained. d (i, 2) and the imaginary part Q d (i, 2), where i=1, 2...N;

[0020] By following this process, inter-frame high-pass filtering of all data is completed, yielding the real part I of all data. d (i, j) and the imaginary part Q d (i, j), where i = 1, 2, ..., N, j = 1, 2, ..., M, where N is the number of frames and M is the length of the received signal in each frame;

[0021] Step 4: Calculate the instantaneous phase and instantaneous frequency of the frame data using the complex covariance frequency measurement method to obtain the instantaneous frequency sequence;

[0022]

[0023]

[0024] Where θ(j) is the instantaneous phase and f(j) is the instantaneous frequency, a point-by-point moving average is performed on f(j) to obtain the measured instantaneous frequency sequence f after moving average. w (j);

[0025] Step 5: Calculate the instantaneous frequency result f obtained from multiple period measurements. w (j) After averaging again, the output is f. p (j); If the measurement period is set to L and the average number of periods is P, then the measurement result output update rate is L×P.

[0026] Step 6: For the instantaneous frequency sequence f after averaging multiple periods p (j) Based on the instantaneous frequency characteristics of the water flow echo, the effective instantaneous frequency is first detected using the amplitude and width determination method. Then, the mean of the effective instantaneous frequency data is calculated as the final instantaneous frequency of the water flow echo signal. Finally, the water flow velocity v is calculated based on the relationship between frequency and flow velocity.

[0027]

[0028] Where F0 is the transmitted signal frequency, F d For the measured instantaneous frequency, The angle between the normal to the transducer plane and the velocity vector.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] 1) The transmitting and receiving transducers of this invention are not designed to be combined, but to be designed separately, eliminating the need for receiving gate settings and effectively reducing the detection blind zone.

[0031] 2) The transmitted signal of this invention is a 1MHz single-frequency signal, based on the flow velocity measurement formula;

[0032]

[0033] It is known that the present invention can achieve fine and high-precision flow velocity measurement, with the highest flow velocity measurement accuracy reaching 1 cm / s.

[0034] 3) This invention can not only measure the water flow velocity, but also measure the height from the transducer emitting surface to the dam surface. The measurement results are simultaneously displayed on the host computer and display software.

[0035] 4) The maximum working depth of this invention can reach 300m, and it can be equipped with robots to detect seepage in deep water and high dams.

[0036] 5) The host computer of the present invention includes a display and control computer and display and control software, which has a data interface with the robot positioning system. It can receive positioning data and package and store flow velocity measurement data, distance from the dam height data and positioning data to realize flow velocity field measurement in the dam surface area and provide spatiotemporal reference for seepage detection.

[0037] 6) The electronic compartment and transducer of the device of the present invention adopt a separate design. The transducer with special installation requirements is small in size and light in weight, and can be easily mounted on any platform. Attached Figure Description

[0038] Figure 1 This is a block diagram of the components of the present invention.

[0039] Figure 2 This is a connection diagram of the present invention when equipped with an underwater ROV.

[0040] Figure 3 This is a schematic diagram of the working timing of the present invention.

[0041] Figure 4 This is a flowchart of the signal processing of the present invention.

[0042] Figure 5 This is a schematic diagram of the inter-frame conversion and inter-frame high-pass filtering process of the present invention.

[0043] Among them, 1-transmitting transducer, 2-transmitting module, 3-receiving transducer, 4-receiving module, 5-main control module, 6-host computer, 61-display and control computer, 62-display and control software, 7-transducer compartment, 8-watertight electronic compartment, 91-data cable, 92-transducer cable, ROV umbilical cord, 93-belt cable, 10-underwater ROV. Detailed Implementation

[0044] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, these descriptions do not constitute a limitation of the present invention and are merely illustrative. The advantages of the present invention will become clearer and easier to understand through this description.

[0045] Referring to the attached figures, the automatic dam leakage detection device based on high-frequency acoustic detection is characterized by comprising: a transmitting transducer 1, a transmitting module 2 connected to the transmitting transducer 1, a receiving transducer 3, a receiving module 4 connected to the receiving transducer 3, a main control module 5 connected to the transmitting module 2 and the receiving module 4, and a host computer 6 connected to the main control module 5, wherein the host computer 6 comprises a display and control computer 61 and display and control software 62.

[0046] The transmitting transducer 1 and receiving transducer 3 are installed on the transducer compartment 7, and the transmitting module 2, receiving module 4 and main control module 5 are installed as a whole in the watertight electronics compartment 8. The separate design ensures that the transducer compartment 7 with special installation requirements is small in size and light in weight, easy to install, and can be easily mounted on any platform. In the absence of special installation requirements, the transducer compartment 7 and the watertight electronics compartment 8 can also be installed in the same pressure-resistant compartment, which can reduce the number of watertight cable connections.

[0047] The watertight electronic compartment 8 communicates with the host computer 6 via data cable 91, and the watertight electronic compartment 8 is connected to the transducer compartment 7 via transducer cable 92.

[0048] The transducer compartment 7 and the watertight electronics compartment 8 are both mounted on the underwater ROV, and the host computer 6 is located on the shore or on the measurement mother ship; the watertight electronics compartment 8 is connected to the underwater ROV 10 via the transducer cable 92, and the underwater ROV 10 is connected to the host computer 6 via the ROV umbilical cable 93.

[0049] The transmitting transducer 1 realizes electroacoustic conversion, the receiving transducer 3 realizes acoustic-electric conversion, the transmitting module 2 is a power amplifier circuit to realize the power amplification of the transmitted signal; the receiving module 4 realizes echo signal filtering, amplification and acquisition; the main control module 5 realizes signal acquisition control, signal processing, network communication and high-frequency drive signal output; the host computer 6 includes a display and control computer and display and control software, which realizes the functions of equipment status control, parameter setting, measurement result and status display and raw data storage.

[0050] The detection method for an automatic dam seepage detection device based on high-frequency acoustic detection is characterized by the following steps:

[0051] like Figure 3 As shown, step 1: Taking the working cycle as the basic working unit, in each working cycle, the transmitting module 2 continuously transmits N frames of signals, and the transmission frame period is T. F The effective pulse width of each frame of signal is T0;

[0052] Each working cycle yields a set of instantaneous frequency sequences. After averaging the instantaneous frequency sequences over P consecutive working cycles, an effective flow velocity and bottom clearance data are calculated and updated in the chart window of the host computer's main interface. That is, the update rate of the data results is P working cycles.

[0053] The water flow velocity is calculated only for the water body near the dam face;

[0054] like Figure 4 As shown, in step 2: after receiving a periodic signal, the receiving module 4 first performs orthogonal transformation and low-pass filtering on the periodic signal to filter out the harmonic components and obtain the difference frequency signal containing the Doppler frequency offset; then, the periodic signal is subjected to inter-frame conversion and inter-frame high-pass filtering to filter out interference signals near the zero frequency; then, the complex cross-covariance frequency measurement method is used to calculate the instantaneous frequency of the inter-frame signal point by point to obtain the instantaneous frequency sequence of the current period;

[0055] To reduce the impact of reverberation and noise interference, the instantaneous frequency measurement sequence is processed by point-by-point moving average in the host computer software to obtain the instantaneous frequency sequence measurement result after moving average; when the number of cycles reaches the set value, the instantaneous frequency sequence measurement results of multiple cycles are averaged, and then the effective instantaneous frequency detection and water flow velocity calculation are performed.

[0056] like Figure 5 As shown, step 3: inter-frame conversion and inter-frame high-pass filtering are described in detail below: Assuming N frames of data are transmitted, after orthogonal transformation and low-pass filtering, N frames of data can also be obtained. Take the first sampling point of the first frame to the Nth frame of data to form a group of data (N sampling points), perform high-pass filtering, and obtain the real part I of this group of data. d (i, 1) and the imaginary part Q d (i, 1), where i=1, 2...N;

[0057] Then, the data from the first frame to the second sampling point of the Nth frame are taken to form a set of data. This set of data is then high-pass filtered to remove the DC component, and the real part I of this set of data is obtained. d (i, 2) and the imaginary part Q d (i, 2), where i=1, 2...N;

[0058] By following this process, inter-frame high-pass filtering of all data is completed, yielding the real part I of all data. d (i, j) and the imaginary part Q d (i, j), where i = 1, 2, ..., N, j = 1, 2, ..., M, where N is the number of frames and M is the length of the received signal in each frame;

[0059] Step 4: Calculate the instantaneous phase and instantaneous frequency of the frame data using the complex covariance frequency measurement method to obtain the instantaneous frequency sequence;

[0060]

[0061]

[0062] Where θ(j) is the instantaneous phase and f(j) is the instantaneous frequency, a point-by-point moving average is performed on f(j) to obtain the measured instantaneous frequency sequence f after moving average. w (j);

[0063] Step 5: Calculate the instantaneous frequency result f obtained from multiple period measurements. w (j) After averaging again, the output is f. p (j); If the measurement period is set to L and the average number of periods is P, then the measurement result output update rate is L×P.

[0064] Step 6: For the instantaneous frequency sequence f after averaging multiple periods p (j) Based on the instantaneous frequency characteristics of the water flow echo, the effective instantaneous frequency is first detected using the amplitude and width determination method. Then, the mean of the effective instantaneous frequency data is calculated as the final instantaneous frequency of the water flow echo signal. Finally, the water flow velocity v is calculated based on the relationship between frequency and flow velocity.

[0065]

[0066] Where F0 is the transmitted signal frequency, F d For the measured instantaneous frequency, Let be the angle between the plane normal of the transmitting transducer 1 and the velocity vector.

[0067] In practical use, the maximum working depth of the transmitting transducer 1, receiving transducer 3 and watertight connector of the present invention can reach 4000m. Therefore, by replacing the watertight pressure chamber, the working depth of the present invention can be extended to 4000m. After the extension, the equipment can be used for fine measurement of deep-sea current velocity.

[0068] This invention operates by default in high-resolution mode, which is suitable for dam seepage measurement. By adjusting the operating parameters, this invention can be switched to a high-velocity range mode, in which the measurable velocity range can be extended to up to 5 m / s, making it suitable for other high-velocity measurement applications.

[0069] All other unspecified parts belong to the prior art.

Claims

1. A detection method for an automatic dam seepage detection device based on high-frequency acoustic detection, characterized in that, The device includes an automatic dam leakage detection device based on high-frequency acoustic detection. The automatic dam leakage detection device based on high-frequency acoustic detection includes a transmitting transducer (1), a transmitting module (2) connected to the transmitting transducer (1), a receiving transducer (3), a receiving module (4) connected to the receiving transducer (3), a main control module (5) connected to the transmitting module (2) and the receiving module (4), and a host computer (6) connected to the main control module (5). The host computer (6) includes a display and control computer (61) and display and control software (62). The method includes the following steps: Step 1: Using the working cycle as the basic working unit, the transmitting module (2) continuously transmits N frames of signals in each working cycle, with a transmission frame period of T. F The effective pulse width of each frame of signal is T0; Each working cycle calculates a set of instantaneous frequency sequences. After averaging the instantaneous frequency sequences of P consecutive working cycles, an effective flow velocity and bottom height data are calculated and updated and displayed in the chart window of the host computer (6) main interface. That is, the update rate of the data results is P working cycles. The water flow velocity is calculated only for the water body near the dam face; Step 2: After receiving a periodic signal, the receiving module (4) first performs orthogonal transformation and low-pass filtering on the periodic signal to filter out the harmonic components and obtain the difference frequency signal containing the Doppler frequency offset; then it performs inter-frame conversion on the periodic signal and performs inter-frame high-pass filtering to filter out interference signals near the zero frequency; then it uses the complex cross-covariance frequency measurement method to calculate the instantaneous frequency of the inter-frame signal point by point to obtain the instantaneous frequency sequence of the current period; Then, the instantaneous frequency measurement sequence is processed by point-by-point moving average to obtain the instantaneous frequency sequence measurement result after moving average; when the number of cycles reaches the set value, the instantaneous frequency sequence measurement results of multiple cycles are averaged by cycle, and then the effective instantaneous frequency detection and water flow velocity calculation are performed. Step 3: The specific processing steps for inter-frame conversion and inter-frame high-pass filtering are described as follows: Assuming N frames of data are transmitted, after orthogonal transformation and low-pass filtering, N frames of data can also be obtained. Take the first sampling point of the first frame to the Nth frame of data to form a group of N sampling points of data, perform high-pass filtering, and obtain the real part I of this group of data. d (i, 1) and the imaginary part Q d (i, 1), where i=1, 2...N; Then, the data from the first frame to the second sampling point of the Nth frame are taken to form a set of data. This set of data is then high-pass filtered to remove the DC component, and the real part I of this set of data is obtained. d (i, 2) and the imaginary part Q d (i, 2), where i=1, 2...N; By following this process, inter-frame high-pass filtering of all data is completed, yielding the real part I of all data. d (i, j) and the imaginary part Q d (i, j), where i = 1, 2, ..., N, j = 1, 2, ..., M, where N is the number of frames and M is the length of the received signal in each frame; Step 4: Calculate the instantaneous phase and instantaneous frequency of the frame data using the complex covariance frequency measurement method to obtain the instantaneous frequency sequence; (Official 1) (Formula 2) Where θ(j) is the instantaneous phase and f(j) is the instantaneous frequency, a point-by-point moving average is performed on f(j) to obtain the measured instantaneous frequency sequence f after moving average. w (j); Step 5: Calculate the instantaneous frequency result f obtained from multiple period measurements. w (j) After averaging again, the output is f. p (j); If the measurement period is set to L and the average number of periods is P, then the measurement result output update rate is L×P. Step 6: For the instantaneous frequency sequence fp(j) after averaging multiple periods, based on the instantaneous frequency characteristics of the water flow echo, firstly, the amplitude and width determination method is used to detect the effective instantaneous frequency. Then, the mean of the effective instantaneous frequency data is calculated as the final instantaneous frequency of the water flow echo signal. Finally, the water flow velocity v is calculated based on the relationship between frequency and flow velocity. Where F0 is the transmitted signal frequency, and Fd is the final instantaneous frequency. φ The angle between the plane normal of the transmitting transducer (1) and the velocity vector.

2. The detection method of the automatic dam seepage detection device based on high-frequency acoustic detection according to claim 1, characterized in that: The transmitting transducer (1) and receiving transducer (3) are installed on the transducer compartment (7), and the transmitting module (2), receiving module (4) and main control module (5) are installed as a whole in the watertight electronic compartment (8).

3. The detection method of the automatic dam seepage detection device based on high-frequency acoustic detection according to claim 2, characterized in that: The watertight electronic compartment (8) communicates with the host computer (6) via a data cable (91), and the watertight electronic compartment (8) is connected to the transducer compartment (7) via a transducer cable (92).

4. The detection method of the automatic dam seepage detection device based on high-frequency acoustic detection according to claim 3, characterized in that: The transducer compartment (7) and the watertight electronics compartment (8) are both mounted on the underwater ROV (10), and the host computer (6) is located on the shore or on the measurement mother ship; the watertight electronics compartment (8) is connected to the underwater ROV (10) via a transducer cable (92), and the underwater ROV (10) is connected to the host computer (6) via an ROV umbilical cable (93).

5. The detection method of the automatic dam seepage detection device based on high-frequency acoustic detection according to claim 4, characterized in that: The transmitting transducer (1) realizes electroacoustic conversion, the receiving transducer (3) realizes acoustic-electric conversion, the transmitting module (2) is a power amplifier circuit, which realizes the power amplification of the transmitted signal; the receiving module (4) realizes the filtering, amplification and acquisition of the echo signal; the main control module (5) realizes signal acquisition control, signal processing, network communication and high-frequency drive signal output, and the host computer (6) includes a display and control computer and display and control software, which realizes the functions of equipment status control, parameter setting, measurement result and status display and raw data storage.

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