Underground cable orientation and burial depth detection method, device and equipment and storage medium

Abstract

The invention provides an underground cable orientation and burial depth detection method, device and equipment and a storage medium, and belongs to the technical field of signal processing. The electromagnetic signals comprise a first electromagnetic signal at a first height and a second electromagnetic signal at a second height of the alternating magnetic field of the underground cable in the transverse axis direction, and a third electromagnetic signal in the longitudinal axis direction; determining the direction of the underground cable according to the first electromagnetic signal and the third electromagnetic signal; and determining the burial depth of the underground cable according to the first electromagnetic signal, the second electromagnetic signal, the first height and the second height. Electromagnetic signals are obtained at different heights and in different directions, so that electromagnetic field distribution information is comprehensive, the direction and height of the alternating magnetic field of the underground cable are clear, and the direction and the burial depth of the underground cable only need to be calculated according to the corresponding electromagnetic signals, so that the underground cable is more accurate. And the orientation and burial depth detection efficiency and detection precision of the underground cable are improved.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, specifically to a method, apparatus, equipment, and storage medium for detecting the orientation and burial depth of underground cables. Background Technology

[0002] With the rapid development of urban power, communication and transportation infrastructure, the types and density of underground cables are constantly increasing. Accurately identifying their spatial orientation and burial depth has become a key link in ensuring construction safety and improving maintenance efficiency.

[0003] Among related technologies, underground cable detection methods mainly include audio induction, electromagnetic induction, ground-penetrating radar, manual polarity determination, and table lookup depth estimation. Audio induction and electromagnetic induction methods typically rely on the cable being energized or having a signal applied, leading to severe signal interference in complex environments and low accuracy. While ground-penetrating radar possesses some penetration capability and can detect non-metallic pipes, it is costly, highly dependent on geological conditions, and its results are complex to interpret. Manual polarity determination and table lookup depth estimation methods are cumbersome to operate, highly subjective, and have limited accuracy. Therefore, existing detection methods are inefficient and prone to large errors, making them unsuitable for high-density, interwoven urban underground pipe networks, thus reducing the efficiency and accuracy of underground cable orientation and burial depth detection. Summary of the Invention

[0004] In view of this, it is necessary to provide a method, apparatus, equipment and storage medium for underground cable orientation and burial depth detection, so as to solve the technical problems of low efficiency and low accuracy of underground cable orientation and burial depth detection in the prior art.

[0005] To address the aforementioned technical problems, in a first aspect, the present invention provides a method for detecting the orientation and burial depth of underground cables, comprising: The electromagnetic signals of the underground cable area are acquired, including a first electromagnetic signal of the alternating magnetic field of the underground cable at a first height in the horizontal direction and a second electromagnetic signal at a second height, and a third electromagnetic signal in the vertical direction. The direction of the underground cable is determined based on the first electromagnetic signal and the third electromagnetic signal; The burial depth of the underground cable is determined based on the first electromagnetic signal, the second electromagnetic signal, the first elevation, and the second elevation.

[0006] In one possible implementation, determining the direction of the underground cable based on the first electromagnetic signal and the third electromagnetic signal includes: The first electromagnetic signal and the third electromagnetic signal are processed differentially to obtain their respective first differential signal and third differential signal; The first differential signal and the third differential signal are respectively subjected to low-pass filtering to obtain the corresponding first filtered signal and third filtered signal; Calculate the first and third main frequency amplitudes corresponding to the first and third filtered signals, respectively; The horizontal angle of the underground cable is determined based on the first and third main frequency amplitudes. The angular direction of the underground cable is determined based on the extreme values ​​in the waveforms corresponding to the first and third main frequency amplitudes.

[0007] In one possible implementation, determining the burial depth of the underground cable based on the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height includes: The first electromagnetic signal and the second electromagnetic signal are processed differentially to obtain their respective first differential signal and second differential signal; The first differential signal and the second differential signal are respectively subjected to low-pass filtering to obtain the corresponding first filtered signal and second filtered signal; Calculate the first and second main frequency amplitudes corresponding to the first and second filtered signals, respectively; The burial depth of the underground cable is determined based on the height difference between the second height and the first height, the first main frequency amplitude, and the second main frequency amplitude.

[0008] In one possible implementation, determining the burial depth of the underground cable based on the height difference between the second height and the first height, the first dominant frequency amplitude, and the second dominant frequency amplitude includes: The burial depth is determined using a preset burial depth prediction model based on the ratio between the first and second main frequency amplitudes and the height difference, wherein the preset burial depth prediction model is a pre-constructed mathematical model of magnetic induction intensity attenuating with vertical distance.

[0009] In one possible implementation, calculating the first and third main frequency amplitudes corresponding to the first and third filtered signals respectively includes: A predetermined percentage of continuous waveform segments located in the center region of the time axis is extracted from the first filtered signal and the third filtered signal respectively to obtain the corresponding first continuous waveform segment and third continuous waveform segment. Perform Fast Fourier Transform on the first continuous waveform segment and the third continuous waveform segment respectively to obtain the corresponding first frequency domain complex coefficient sequence and third frequency domain complex coefficient sequence; Based on the target frequency, calculate the Fourier coefficients corresponding to the first frequency domain complex coefficient sequence and the third frequency domain complex coefficient sequence respectively, and obtain the corresponding first frequency amplitude and third frequency amplitude.

[0010] In one possible implementation, determining the horizontal angle of the underground cable based on the first dominant frequency amplitude and the third dominant frequency amplitude includes: Based on the preset structural ratio, the ratio between the third main frequency amplitude and the first main frequency amplitude, the horizontal angle of the underground cable is calculated using the arctangent function.

[0011] In one possible implementation, determining the angular direction of the underground cable based on the extreme values ​​in the waveforms corresponding to the first and third dominant frequency amplitudes includes: Obtain the corresponding first extreme value from the first waveform corresponding to the first main frequency amplitude; The corresponding third extreme value is obtained from the first basic sub-waveform of the third waveform corresponding to the third dominant frequency amplitude, wherein the first basic sub-waveform is a sub-waveform within the first basic time window of the third waveform, and the first basic time window is the time window where the first extreme value is located; or... Obtain the corresponding third extreme value from the third waveform corresponding to the third main frequency amplitude; The third extreme value is obtained from the second basic sub-waveform in the first waveform corresponding to the first main frequency amplitude, wherein the second basic sub-waveform is the sub-waveform under the second basic time window in the first waveform, and the second basic time window is the time window where the third extreme value is located; The angular direction of the underground cable is determined based on the sign of the first and third extreme values.

[0012] Secondly, the present invention also provides an underground cable orientation and burial depth detection device, comprising: The acquisition unit is used to acquire electromagnetic signals in the underground cable area. The electromagnetic signals include a first electromagnetic signal of the alternating magnetic field of the underground cable at a first height in the horizontal axis direction, a second electromagnetic signal at a second height, and a third electromagnetic signal in the vertical axis direction. A direction detection unit is used to determine the direction of the underground cable based on the first electromagnetic signal and the third electromagnetic signal; The burial depth detection unit is used to determine the burial depth of the underground cable based on the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

[0013] Thirdly, the present invention also provides an underground cable orientation and burial depth detection device, including an electromagnetic signal acquisition device and a processor, wherein the electromagnetic signal acquisition device and the processor are communicatively connected, and the electromagnetic signal acquisition device is equipped with a first solenoid sensing module, a second solenoid sensing module, a third solenoid sensing module, and a fourth solenoid sensing module, with the axis of the electromagnetic signal acquisition device being set along the horizontal axis of the spatial rectangular coordinate system in which the underground cable is located and located at a first height and a second height respectively, and the electromagnetic signal acquisition device is equipped with a first solenoid sensing module, a second solenoid sensing module, a third solenoid sensing module with the axis of the electromagnetic signal acquisition device being set along the vertical axis of the spatial rectangular coordinate system in which the underground cable is located, and a fourth solenoid sensing module with the axis of the electromagnetic signal acquisition device being set along the vertical axis of the spatial rectangular coordinate system in which the underground cable is located, and the first solenoid sensing module and the third solenoid sensing module are located at the same height; The first solenoid sensing module and the second solenoid sensing module are used to collect the first electromagnetic signal and the second electromagnetic signal, respectively. The third solenoid sensing module is used to collect the third electromagnetic signal; The fourth solenoid sensing module is used to verify the reference position of the underground cable located directly below the electromagnetic signal acquisition device; The processor is configured to determine the direction of the underground cable based on the first electromagnetic signal and the third electromagnetic signal; and to determine the burial depth of the underground cable based on the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

[0014] Fourthly, the present invention also provides a computer-readable storage medium for storing a computer-readable program or instruction, which, when executed by a processor, can implement the steps in the underground cable orientation and burial depth detection method described in any of the above implementations.

[0015] The beneficial effects of this invention are: The method for directional and burial depth detection of underground cables provided by this invention acquires electromagnetic signals from the underground cable area. These electromagnetic signals include a first electromagnetic signal at a first height and a second electromagnetic signal at a second height along the horizontal axis, and a third electromagnetic signal along the vertical axis. By acquiring electromagnetic signals at two different heights, the distribution of the cable's alternating magnetic field at different spatial locations can be captured. Acquiring the electromagnetic signal along the vertical axis ensures that the acquired signal originates from the corresponding direction of the underground cable, eliminating interference from signals in other directions. Acquiring electromagnetic signals at different heights and directions not only provides comprehensive information on the electromagnetic field distribution but also, because the direction and height of the alternating magnetic field of the underground cable are clearly defined, enables rapid and accurate detection of the cable's orientation and burial depth based on the corresponding electromagnetic signals. The direction of the underground cable is determined based on the first and third electromagnetic signals. Based on the circular distribution of the magnetic field around the underground cable, the direction of the underground cable is determined according to the first and third electromagnetic signals. This method not only has a clear and reasonable calculation basis, but also only requires electromagnetic signals from two directions, making the calculation simple and convenient, thus improving the efficiency of underground cable direction detection and ensuring the rationality of the calculation. Furthermore, based on the first and second electromagnetic signals, the first and second elevations, the burial depth of the underground cable is determined. This method uses the circular distribution of the magnetic field around the underground cable and the power-law decay of the alternating magnetic field strength with distance as a basis. This method not only has a clear and reasonable calculation basis, but also only requires electromagnetic signals from two directions and the vertical elevation, making the calculation simple and convenient, thus improving the efficiency of underground cable burial depth detection and ensuring the rationality of the calculation. This method improves the accuracy of underground cable burial depth detection, thereby enhancing the efficiency and accuracy of underground cable orientation and burial depth detection. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic flowchart of an embodiment of the underground cable orientation and burial depth detection method provided by the present invention; Figure 2 This is a schematic diagram of the layout of the four solenoid sensing modules provided by the present invention; Figure 3 A schematic diagram of an embodiment of the underground cable orientation and burial depth detection device provided by the present invention; Figure 4 This is a schematic diagram of an embodiment of the underground cable orientation and burial depth detection device provided by the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present invention, unless otherwise stated, "a plurality of" means two or more.

[0020] The terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a technical feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] This invention provides a method, apparatus, equipment, and storage medium for detecting the orientation and burial depth of underground cables, which will be described below.

[0023] The underground cable orientation and burial depth detection method provided in this application can be applied to urban underground utility tunnels (such as trenchless inspection and three-dimensional coordinate survey of high-voltage cables, communication optical cables, and rail transit power supply cables in existing or renovated utility tunnels), road reconstruction and expansion and subway construction pre-construction surveys (such as rapid scanning of the precise location and depth information of unknown cables within the work red line before road widening and subway shield / pipe jacking construction), urban power grid maintenance, transportation infrastructure construction, and underground pipeline safety inspection.

[0024] The execution entity of the underground cable orientation and burial depth detection method in this application embodiment can be the underground cable orientation and burial depth detection equipment provided in this application embodiment. The underground cable orientation and burial depth detection equipment includes an electromagnetic signal acquisition device and a processor for acquiring electromagnetic signals of the underground cable area. The electromagnetic signals include a first electromagnetic signal at a first height and a second electromagnetic signal at a second height in the horizontal axis direction, and a third electromagnetic signal in the vertical axis direction, representing the alternating magnetic field of the underground cable. The processor is used to determine the direction of the underground cable based on the first electromagnetic signal and the third electromagnetic signal; and to determine the burial depth of the underground cable based on the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

[0025] Figure 1 This is a schematic flowchart of an embodiment of the underground cable orientation and burial depth detection method provided by the present invention, as shown below. Figure 1 As shown, the methods for directional and burial depth detection of underground cables include: S101. Obtain electromagnetic signals from the underground cable area, wherein the electromagnetic signals include a first electromagnetic signal of the alternating magnetic field of the underground cable at a first height in the horizontal direction and a second electromagnetic signal at a second height, and a third electromagnetic signal in the vertical direction.

[0026] The first and second electromagnetic signals represent the magnetic field strength of the underground cable's alternating magnetic field along the horizontal axis (X-axis) at different heights. The third electromagnetic signal represents the magnetic field strength of the underground cable's alternating magnetic field along the vertical axis (Y-axis).

[0027] Specifically, two electromagnetic induction modules (such as solenoid induction modules) at different heights can be set in the horizontal direction of the underground cable area, with the two electromagnetic induction modules located at a first height and a second height, respectively. At least one electromagnetic induction module can be set in the vertical direction of the underground cable area to obtain the first electromagnetic signal of the alternating magnetic field of the underground cable at the first height and the second electromagnetic signal at the second height in the horizontal direction, and to obtain the third electromagnetic signal of the alternating magnetic field of the underground cable in the vertical direction.

[0028] Understandably, by acquiring electromagnetic signals at two different heights, the distribution of the cable's alternating magnetic field at different spatial locations can be captured. By acquiring electromagnetic signals along the longitudinal axis, it is ensured that the acquired electromagnetic signals originate from the corresponding direction of the underground cable, eliminating interference from signals in other directions. Acquiring electromagnetic signals at different heights and in different directions not only provides comprehensive information on the electromagnetic field distribution, but also, because the direction and height of the underground cable's alternating magnetic field are clearly defined, enables rapid and accurate detection of the underground cable's orientation and burial depth based on the corresponding electromagnetic signals.

[0029] It is worth noting that the first, second, and third electromagnetic signals in this embodiment are obtained through synchronous acquisition, ensuring that the electromagnetic signals are aligned on the time axis. This allows for accurate comparison and analysis of the signal strength and phase information received at the same time, improving the accuracy of the orientation and burial depth detection of underground cables.

[0030] In one specific embodiment, the first, second, and third electromagnetic signals can be synchronously acquired using an electromagnetic signal acquisition device. This device contains four solenoid induction modules, such as... Figure 2 The diagram shows the layout of four solenoid sensing modules. The first solenoid sensing module 10, the third solenoid sensing module 20, and the fourth solenoid sensing module 30 are arranged along the X, Y, and Z axes of the Cartesian coordinate system where the underground cable is located, forming an orthogonal three-axis structure. The first solenoid sensing module 10 and the second solenoid sensing module 40 are arranged parallel to each other. The ferrite cores of the solenoids in each solenoid sensing module are identical, with the first solenoid sensing module 10 and the second solenoid sensing module 40 having completely identical material specifications. The third solenoid sensing module 20 is perpendicular to the detection plane and is used to assist in identifying the verticality of the scene. The second solenoid sensing module 40 is parallel to the first solenoid sensing module 10 but located at different heights, while the first solenoid sensing module 10 and the third solenoid sensing module 20 are located at the same height. Each solenoid sensing module includes two symmetrical antennas and a high-frequency analog-to-digital converter (ADC). The ADC receives the analog signals collected by the two symmetrical antennas (each solenoid coil is connected to two differential antennas via coils at both ends), and converts them into digital channel data after high-speed sampling. The symmetrical antennas are used to verify the position directly above the underground cable and begin collecting electromagnetic signals. During acquisition, the electromagnetic signal acquisition device can be suspended above the underground cable, and adjustments are made in real time by monitoring the signal strength of the third solenoid sensing module 20. When the signal of the third solenoid sensing module 20 is at its minimum, it is confirmed that the device is directly above the underground cable. The four solenoid sensing modules sample synchronously at a sampling rate of up to 800kHz to ensure the waveform integrity of the collected electromagnetic signals, and the signal acquisition can cover multiple cycles (e.g., 10 cycles) to ensure computational stability.

[0031] S102. Determine the direction of the underground cable based on the first electromagnetic signal and the third electromagnetic signal.

[0032] The direction refers to the angular direction of the underground cable in the horizontal plane.

[0033] Specifically, since underground cables can be simplified as infinitely long straight conductors carrying alternating current, according to the Biot-Savart law, their surrounding magnetic field is distributed concentrically in the horizontal plane, with the field strength direction perpendicular to the cable's axis at every point. The first and third electromagnetic signals characterize the magnetic field strength of the alternating magnetic field of the underground cable at the same measuring point in two orthogonal directions within the horizontal plane. Therefore, the direction of the underground cable can be determined based on the first and third electromagnetic signals. In this embodiment, the circular distribution of the magnetic field around the underground cable is used as the calculation basis. The direction of the underground cable is determined based on the first and third electromagnetic signals. This not only provides a clear and reasonable calculation basis but also requires only electromagnetic signals from two directions, making the calculation simple and convenient. This improves the efficiency of underground cable direction detection, ensures the rationality of the calculation, and enhances the accuracy of underground cable direction detection.

[0034] S103. Determine the burial depth of the underground cable based on the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

[0035] Among them, the burial depth refers to the vertical distance between the axis of the underground cable and the solenoid induction module at the bottom of the electromagnetic signal acquisition device.

[0036] Specifically, since underground cables can be simplified as infinitely long straight conductors carrying alternating current, according to the Biot-Savart law, their surrounding magnetic field is distributed concentrically in the horizontal plane, with the field strength direction perpendicular to the cable's axis at every point. Since the first and third electromagnetic signals characterize the magnetic field strength of the alternating magnetic field at different heights along the same horizontal axis, and according to the Biot-Savart law and the near-field power-law attenuation principle, the alternating magnetic field strength decreases with distance using a power function, the burial depth of the underground cable can be determined by analyzing the amplitudes of the first and second electromagnetic signals and their difference from the known height. Therefore, the burial depth of the underground cable can be determined based on the first and third electromagnetic signals, the first height, and the second height. In this embodiment, the burial depth of the underground cable is determined based on the circular distribution of the magnetic field around the underground cable and the power function decay of the alternating magnetic field intensity with distance. The burial depth of the underground cable is determined based on the first electromagnetic signal, the third electromagnetic signal, the first height, and the second height. The calculation basis is not only clear and reasonable, but also only requires electromagnetic signals in two directions and vertical height to determine the depth. The calculation is simple and convenient, which improves the detection efficiency of the burial depth of the underground cable, ensures the rationality of the calculation, and can improve the detection accuracy of the burial depth of the underground cable.

[0037] In summary, the underground cable orientation and burial depth detection method provided by this invention acquires electromagnetic signals from the underground cable area. These electromagnetic signals include a first electromagnetic signal at a first height in the horizontal direction and a second electromagnetic signal at a second height, and a third electromagnetic signal in the vertical direction. By acquiring electromagnetic signals at two different heights, the distribution of the cable's alternating magnetic field at different spatial locations can be captured. By acquiring the electromagnetic signal in the vertical direction, it is ensured that the acquired electromagnetic signal originates from the corresponding direction of the underground cable, eliminating interference from signals in other directions. Acquiring electromagnetic signals at different heights and directions not only provides comprehensive information on the electromagnetic field distribution but also, because the direction and height of the underground cable's alternating magnetic field are clearly defined, enables rapid and accurate detection of the underground cable's orientation and burial depth based on the corresponding electromagnetic signals. Based on the first electromagnetic signal... The direction of underground cables is determined by a third electromagnetic signal, using the circular distribution of the magnetic field around the underground cable as the basis for calculation. The direction of the underground cable is determined based on the first and third electromagnetic signals. This method not only has a clear and reasonable calculation basis but also only requires electromagnetic signals from two directions, making the calculation simple and convenient, improving the efficiency of underground cable direction detection, ensuring the rationality of the calculation, and improving the accuracy of underground cable direction detection. The burial depth of underground cables is determined based on the first and second electromagnetic signals, the first height, and the second height. This method uses the circular distribution of the magnetic field around the underground cable and the power-law decay of the alternating magnetic field intensity with distance as the basis for calculation. This method not only has a clear and reasonable calculation basis but also only requires electromagnetic signals from two directions and the vertical height, making the calculation simple and convenient, improving the efficiency of underground cable depth detection, ensuring the rationality of the calculation, and improving the accuracy of underground cable depth detection. For high-density, interwoven urban underground pipe networks, this method overcomes the problems of large signal interference, strong subjectivity in extreme value identification, difficulty in direction determination, and large errors in burial depth estimation found in traditional methods. It achieves intelligent and automated underground cable path and depth measurement, effectively improving on-site detection efficiency and discrimination accuracy.

[0038] In some embodiments of the present invention, step S102 includes: S201. Perform differential processing on the first electromagnetic signal and the third electromagnetic signal respectively to obtain the corresponding first differential signal and third differential signal; S202. Perform low-pass filtering on the first differential signal and the third differential signal respectively to obtain the corresponding first filtered signal and third filtered signal; S203. Calculate the first main frequency amplitude and the third main frequency amplitude corresponding to the first filtered signal and the third filtered signal, respectively; S204. Determine the horizontal angle of the underground cable based on the first main frequency amplitude and the third main frequency amplitude; S205. Determine the angular direction of the underground cable based on the extreme values ​​in the waveforms corresponding to the first main frequency amplitude and the third main frequency amplitude, respectively.

[0039] The low-pass filter can be a Butterworth low-pass filter, with its cutoff frequency set to a smaller frequency, either 10% of the sampling frequency or 5 times the target signal frequency, to remove high-frequency interference. Since the Butterworth filter belongs to the ripple-free maximum flatness class of filters, it has the characteristic of having the flattest and most undulating frequency response within the passband, making it suitable for the faithful extraction of the dominant frequency component from electromagnetic waveform signals, and especially suitable for feature enhancement processing in non-abrupt, periodic signal environments.

[0040] In one specific approach, the filter's cutoff frequency Determined according to the following formula:

[0041] in, The sampling rate of the current differential signal. The main frequency is selected, and the cutoff frequency is chosen as the smaller of the two.

[0042] Specifically, the first electromagnetic signal is differentially processed to obtain a first differential signal, and the third electromagnetic signal is differentially processed to obtain a third differential signal, thereby significantly suppressing in-phase noise and system drift, and enhancing the magnetic field gradient information of the underground cable. Then, the first differential signal is low-pass filtered to obtain a first filtered signal, and the third differential signal is low-pass filtered to obtain a third filtered signal, in order to remove high-frequency interference and enhance the differential signals. Next, the first and third dominant frequency amplitudes corresponding to the first and third filtered signals are calculated. Finally, the horizontal angle of the underground cable is determined based on the ratio between the first and third dominant frequency amplitudes, and the angular direction of the underground cable is determined based on the extreme values ​​in the waveforms corresponding to the first and third dominant frequency amplitudes.

[0043] Understandably, in this embodiment, by performing differential processing and low-pass filtering on the electromagnetic signal, noise interference is removed, ensuring the purity and reliability of the main frequency amplitude. The direction detection of the underground cable is performed based on the main frequency amplitude of the electromagnetic signal, which improves the accuracy and robustness of the determination of the underground cable angle and angular direction.

[0044] In one specific implementation, both the first and third electromagnetic signals include a corresponding set of antenna channel signals, which are acquired through sampling ports connected to two opposite directions of the solenoid sensing module. In this embodiment, with four solenoid sensing modules, four differential channels (AIN1–AIN4) are formed. The two antenna channel signals of each solenoid sensing module are differentially calculated to generate an effective signal reflecting the change in electric field gradient, and to significantly suppress in-phase noise and system drift. That is, each symmetrical antenna channel (such as CH1 and CH2, CH3 and CH4, etc.) is combined into a differential pair, and after differential calculation, they are denoted as AIN1, AIN2, AIN3, and AIN4, respectively, corresponding to the differential signals of the four solenoid sensing modules. The formula is as follows:

[0045]

[0046]

[0047]

[0048] It is worth noting that, in order to ensure the synchronization and waveform alignment of the differential signals, the electromagnetic signals use the same time base and record the timestamp field for analysis.

[0049] In some embodiments of the present invention, step S103 includes: S301. Perform differential processing on the first electromagnetic signal and the second electromagnetic signal respectively to obtain the corresponding first differential signal and second differential signal; S302. Perform low-pass filtering on the first differential signal and the second differential signal respectively to obtain the corresponding first filtered signal and second filtered signal; S303. Calculate the first main frequency amplitude and the second main frequency amplitude corresponding to the first filtered signal and the second filtered signal, respectively; S304. Determine the burial depth of the underground cable based on the height difference between the second height and the first height, the first main frequency amplitude, and the second main frequency amplitude.

[0050] The differential processing and low-pass filtering methods in this embodiment are the same as those in the above embodiments, and will not be repeated here.

[0051] Specifically, the first and second dominant frequency amplitudes corresponding to the first and second filtered signals are calculated. Based on the height difference between the second and first heights and the ratio between the first and second dominant frequency amplitudes, the burial depth of the underground cable can be determined. Understandably, in this embodiment, by performing differential processing and low-pass filtering on the electromagnetic signal, noise interference is removed, ensuring the purity and reliability of the dominant frequency amplitude. The accuracy and robustness of determining the burial depth of the underground cable are improved by using the dominant frequency amplitude and height difference of the electromagnetic signal.

[0052] In some embodiments of the present invention, step S304 includes: S401. Based on the ratio between the first main frequency amplitude and the second main frequency amplitude and the height difference, the burial depth is determined using a preset burial depth prediction model, wherein the preset burial depth prediction model is a pre-constructed mathematical model of magnetic induction intensity attenuating with vertical distance.

[0053] Specifically, by substituting the ratio between the first and second dominant frequency amplitudes and the height difference into the preset burial depth prediction model, the burial depth of the underground cable can be inverted.

[0054] In one specific implementation, the first main frequency amplitude and the second main frequency amplitude are respectively denoted as... , In this configuration, the solenoid sensing module corresponding to the first main frequency amplitude is a coil channel close to the ground, with a height of denoted as the first height. The solenoid sensing module corresponding to the second main frequency amplitude is an upper coil channel farther from the ground, with a height of denoted as the second height. The height difference between the second height and the first height is a known fixed value. ; An empirical amplitude decay model is constructed, which is a mathematical model of the decay of magnetic induction intensity with vertical distance. The formula is as follows:

[0055] in, , These are the main frequency amplitudes of the lower and upper receiving coils, respectively, i.e., the first main frequency amplitude and the second main frequency amplitude. This is the vertical distance from the underground cable to the lower receiving coil, i.e., the required burial depth. The height difference between the two coils The exponential attenuation factor (related to frequency, antenna size, and cable depth range) fitted based on measured data approaches 1. This model is essentially an approximation of the attenuation law of the alternating magnetic field generated by alternating current in space. Its physical basis can be traced back to the Biot-Savart Law, which describes the characteristic that the contribution of any current element to the magnetic field at a point in space decreases inversely with the square of the distance. Since the near-field induced signal collected in this application is under specific frequency conditions, the actual attenuation behavior tends to be power-law attenuation. Therefore, using this structural model can balance physical consistency and engineering solvability. The ratio between the first main frequency amplitude and the second main frequency amplitude Substitute into the formula, and combine with the known... The attenuation factor obtained by fitting The burial depth can be obtained by inverse solving. The inverse solution formula is:

[0056] When the denominator in the above formula approaches zero (i.e., the amplitudes of the two channels are very close), a reasonable threshold processing strategy should be set to avoid numerical instability; when the amplitude ratio deviates significantly from the theoretical range, an acquisition anomaly can be indicated. Since the first and second dominant frequency amplitudes respectively characterize the magnetic field strength of the underground cable's alternating magnetic field at the same horizontal component but different vertical heights, the amplitude difference between the two directly reflects the law of magnetic field attenuation with distance. Therefore, the burial depth of the underground cable can be uniquely inverted based on this.

[0057] In some embodiments of the present invention, step S203 includes: S501. Extract a preset percentage of continuous waveform segments located in the center region of the time axis from the first filtered signal and the third filtered signal respectively to obtain the corresponding first continuous waveform segment and third continuous waveform segment. S502. Perform fast Fourier transform on the first continuous waveform segment and the third continuous waveform segment respectively to obtain the corresponding first frequency domain complex coefficient sequence and third frequency domain complex coefficient sequence. S503. Based on the target main frequency, calculate the Fourier coefficients corresponding to the first frequency domain complex coefficient sequence and the third frequency domain complex coefficient sequence respectively, and obtain the corresponding first main frequency amplitude and third main frequency amplitude.

[0058] The preset percentage can be 50%, meaning that 50% of the continuous waveform segment in the center region of the first waveform corresponding to the first filtered signal is selected as the first continuous waveform segment, and 50% of the continuous waveform segment in the center region of the third waveform corresponding to the third filtered signal is selected as the third continuous waveform segment. By extracting the continuous waveform segments of the preset percentage in the center region, edge signal disturbances are eliminated.

[0059] Target frequency refers to the actual operating frequency of the underground cable. f .

[0060] Specifically, an N-point Fast Fourier Transform (FFT) is performed on the first and third continuous waveform segments respectively to obtain their corresponding first and third frequency domain complex coefficient sequences. Based on the target dominant frequency, the Fourier coefficients corresponding to the first and third frequency domain complex coefficient sequences are calculated to obtain their respective first and third dominant frequency amplitudes. Understandably, in this embodiment, by extracting a predetermined percentage of continuous waveform segments located in the center region of the time axis from the filtered signal, unstable edge signals are eliminated, further ensuring the purity and reliability of the signal, thereby further improving the accuracy of the dominant frequency amplitude.

[0061] In one specific implementation, the main frequency amplitude It can be calculated using the following formula:

[0062] in, f For the target clock frequency, N For sampling points, The Fourier coefficients are the target frequency.

[0063] In some embodiments of the present invention, step S204 includes: S601. Based on the preset structural ratio, the ratio between the third main frequency amplitude and the first main frequency amplitude, the horizontal angle of the underground cable is calculated using the arctangent function.

[0064] The preset structure ratio is a pre-calibrated coil geometry and electromagnetic coupling coefficient, which can be obtained by fitting multiple sets of true data in advance. Specifically, the horizontal angle θ of the underground cable can be calculated using the following formula:

[0065] Where K is the preset structure ratio, , 1 represents the amplitude of the third main frequency and the amplitude of the first main frequency, respectively. It is the ratio between the amplitude of the third main frequency and the amplitude of the first main frequency.

[0066] In some embodiments of the present invention, step 205 includes: S701. Obtain the corresponding first extreme value from the first waveform corresponding to the first main frequency amplitude; S702. Obtain the corresponding third extreme value from the first basic sub-waveform of the third waveform corresponding to the third dominant frequency amplitude, wherein the first basic sub-waveform is a sub-waveform within the first basic time window of the third waveform, and the first basic time window is the time window where the first extreme value is located; or... S703. Obtain the corresponding third extreme value from the third waveform corresponding to the third main frequency amplitude; S704. Obtain the third extreme value from the second basic sub-waveform in the first waveform corresponding to the first main frequency amplitude, wherein the second basic sub-waveform is the sub-waveform under the second basic time window in the first waveform, and the second basic time window is the time window where the third extreme value is located. S705. Determine the angular direction of the underground cable based on the sign of the first extreme value and the third extreme value.

[0067] Specifically, the extreme values ​​of the first and third filtered signals within the same time window are compared synchronously. If the polarities are the same, the angle direction of the underground cable is determined to be clockwise; if the polarities are opposite, the angle direction of the underground cable is determined to be counterclockwise.

[0068] It should be noted that after calculating the direction and burial depth of the underground cable, the calculated burial depth result can be combined with the ground calibration information to generate a burial depth distribution map or data report, which, together with the direction information, can be used as input parameters for three-dimensional modeling of the underground cable path, realizing the integrated calculation of the spatial angle direction and depth of the underground cable. To better implement the underground cable orientation and burial depth detection method in this embodiment of the invention, based on the underground cable orientation and burial depth detection method, correspondingly, as follows: Figure 3 As shown, this embodiment of the invention also provides an underground cable orientation and burial depth detection device. The underground cable orientation and burial depth detection device 300 includes: Acquisition unit 301 is used to acquire electromagnetic signals in the underground cable area. The electromagnetic signals include a first electromagnetic signal of the alternating magnetic field of the underground cable at a first height in the horizontal direction and a second electromagnetic signal at a second height, and a third electromagnetic signal in the vertical direction. Direction detection unit 302 is used to determine the direction of the underground cable based on the first electromagnetic signal and the third electromagnetic signal; The burial depth detection unit 303 is used to determine the burial depth of the underground cable based on the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

[0069] The underground cable orientation and burial depth detection device 300 provided in the above embodiments can realize the technical solutions described in the above underground cable orientation and burial depth detection method embodiments. The specific implementation principles of each module or unit can be found in the corresponding content in the above underground cable orientation and burial depth detection method embodiments, which will not be repeated here.

[0070] like Figure 4 As shown, the present invention also provides an underground cable orientation and burial depth detection device 400. The underground cable orientation and burial depth detection device 400 includes an electromagnetic signal acquisition device 401 and a processor 402 connected by communication. The electromagnetic signal acquisition device 401 is equipped with a first solenoid sensing module, a second solenoid sensing module, a third solenoid sensing module, and a fourth solenoid sensing module, all positioned at a first height and a second height, with their axes aligned along the horizontal axis of the spatial rectangular coordinate system where the underground cable is located. The first and third solenoid sensing modules are located at the same height. The first and second solenoid sensing modules are used to acquire the first and second electromagnetic signals, respectively. The third solenoid sensing module is used to acquire the third electromagnetic signal. The fourth solenoid sensing module is used to verify the reference position of the underground cable directly below the electromagnetic signal acquisition device. The processor 402 is used to determine the direction of the underground cable based on the first and third electromagnetic signals and to determine the burial depth of the underground cable based on the first and second electromagnetic signals, the first height, and the second height.

[0071] Understandably, the electromagnetic signal acquisition device 401 in this embodiment, by utilizing four rationally distributed solenoid induction modules to construct a structure with three orthogonal axes and a parallel axis, overcomes the problem of significant signal interference in traditional methods by utilizing the signal intensity variation relationship at different induction positions in space, thus ensuring the accuracy of the electromagnetic signals. The direction of the underground cable is determined based on the first and third electromagnetic signals; the burial depth of the underground cable is determined based on the first and second electromagnetic signals, the first elevation, and the second elevation, thereby improving the efficiency and accuracy of underground cable orientation and burial depth detection.

[0072] Furthermore, this embodiment of the invention does not specifically limit the type of the underground cable orientation and burial depth detection device 400 mentioned. The underground cable orientation and burial depth detection device 400 can be a portable underground cable orientation and burial depth detection device such as a mobile phone, tablet computer, personal digital assistant (PDA), wearable device, or laptop computer. Exemplary embodiments of portable underground cable orientation and burial depth detection devices include, but are not limited to, portable underground cable orientation and burial depth detection devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable underground cable orientation and burial depth detection device can also be other portable underground cable orientation and burial depth detection devices, such as laptop computers with touch-sensitive surfaces (e.g., touch panels). It should also be understood that in some other embodiments of the invention, the underground cable orientation and burial depth detection device 400 may not be a portable underground cable orientation and burial depth detection device, but rather a desktop computer with a touch-sensitive surface (e.g., touch panel).

[0073] Accordingly, this application also provides a computer-readable storage medium for storing computer-readable programs or instructions. When the programs or instructions are executed by a processor, they can implement the steps or functions of the underground cable orientation and burial depth detection methods provided in the above-described method embodiments.

[0074] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware (such as a processor, controller, etc.), and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0075] The above provides a detailed description of the underground cable orientation and burial depth detection method, apparatus, equipment, and storage medium provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method of underground cable orientation and depth detection, characterized in that, The method comprises: acquiring an electromagnetic signal of a region of a buried cable, the electromagnetic signal comprising a first electromagnetic signal at a first height in a transverse direction and a second electromagnetic signal at a second height of an alternating magnetic field of the buried cable, and a third electromagnetic signal in a longitudinal direction; determining a direction of the buried cable according to the first electromagnetic signal and the third electromagnetic signal; determining a burial depth of the buried cable according to the first electromagnetic signal, the second electromagnetic signal, the first height and the second height.

2. The underground cable orientation and depth of burial method of claim 1, wherein, The determining of the direction of the buried cable according to the first electromagnetic signal and the third electromagnetic signal comprises: differentially processing the first electromagnetic signal and the third electromagnetic signal respectively to obtain corresponding first differential signals and third differential signals respectively; low-pass filtering the first differential signals and the third differential signals respectively to obtain corresponding first filtered signals and third filtered signals; calculating first main frequency amplitudes and third main frequency amplitudes corresponding to the first filtered signals and the third filtered signals respectively; determining a horizontal included angle of the buried cable according to the first main frequency amplitudes and the third main frequency amplitudes; determining an angular direction of the buried cable according to extreme values in waveforms corresponding to the first main frequency amplitudes and the third main frequency amplitudes respectively.

3. The subsurface cable orientation and depth of burial method of claim 1, wherein, The determining of the burial depth of the buried cable according to the first electromagnetic signal, the second electromagnetic signal, the first height and the second height comprises: differentially processing the first electromagnetic signal and the second electromagnetic signal respectively to obtain corresponding first differential signals and second differential signals respectively; low-pass filtering the first differential signals and the second differential signals respectively to obtain corresponding first filtered signals and second filtered signals; calculating first main frequency amplitudes and second main frequency amplitudes corresponding to the first filtered signals and the second filtered signals respectively; determining the burial depth of the buried cable according to a height difference between the second height and the first height, the first main frequency amplitudes and the second main frequency amplitudes.

4. The subsurface cable orientation and depth of burial method of claim 3, wherein, The determining of the burial depth of the buried cable according to the height difference between the second height and the first height, the first main frequency amplitudes and the second main frequency amplitudes comprises: determining the burial depth by using a preset burial depth prediction model according to a ratio between the first main frequency amplitudes and the second main frequency amplitudes and the height difference, wherein the preset burial depth prediction model is a mathematical model of magnetic induction intensity decay with vertical distance.

5. The subsurface cable orientation and depth of burial method of claim 2, wherein, The calculating of the first main frequency amplitudes and the third main frequency amplitudes corresponding to the first filtered signals and the third filtered signals respectively comprises: cutting continuous waveform segments located in a preset percentage of a central region of a time axis from the first filtered signals and the third filtered signals respectively to obtain corresponding first continuous waveform segments and third continuous waveform segments; performing fast Fourier transform on the first continuous waveform segments and the third continuous waveform segments respectively to obtain corresponding first frequency domain complex coefficient sequences and third frequency domain complex coefficient sequences; calculating Fourier coefficients corresponding to the first frequency domain complex coefficient sequences and the third frequency domain complex coefficient sequences respectively according to a target main frequency to obtain the first main frequency amplitudes and the third main frequency amplitudes respectively.

6. The subsurface cable orientation and depth of burial method of claim 2, wherein, The determining the horizontal angle of the underground cable according to the first main frequency amplitude and the third main frequency amplitude comprises: According to the preset structure ratio, the ratio between the third main frequency amplitude and the first main frequency amplitude, and through the arctangent function, the horizontal angle of the underground cable is calculated.

7. The subsurface cable orientation and depth of burial method of claim 1, wherein, The determining the angle direction of the underground cable according to the extreme value in the waveform corresponding to the first main frequency amplitude and the third main frequency amplitude respectively comprises: The corresponding first extreme value is obtained from the first waveform corresponding to the first main frequency amplitude; The corresponding third extreme value is obtained from the first basic sub waveform of the third waveform corresponding to the third main frequency amplitude, wherein the first basic sub waveform is the sub waveform under the first basic time window of the third waveform, and the first basic time window is the time window where the first extreme value is located; or, The corresponding third extreme value is obtained from the third waveform corresponding to the third main frequency amplitude; The third extreme value is obtained from the second basic sub waveform in the first waveform corresponding to the first main frequency amplitude, wherein the second basic sub waveform is the sub waveform under the second basic time window of the first waveform, and the second basic time window is the time window where the third extreme value is located; According to the positive and negative nature of the first extreme value and the third extreme value, the angle direction of the underground cable is determined.

8. An underground cable orientation and depth finder apparatus, characterized by, Comprise: The acquisition unit is used for acquiring electromagnetic signals of an underground cable area, and the electromagnetic signals comprise a first electromagnetic signal at a first height in a horizontal axis direction, a second electromagnetic signal at a second height, and a third electromagnetic signal in a vertical axis direction of an alternating magnetic field of the underground cable; The direction detection unit is used for determining the direction of the underground cable according to the first electromagnetic signal and the third electromagnetic signal; The buried depth detection unit is used for determining the buried depth of the underground cable according to the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

9. An underground cable orientation and depth finder apparatus, characterized by, Comprise an electromagnetic signal acquisition device and a processor, wherein the electromagnetic signal acquisition device and the processor are in communication connection, the electromagnetic signal acquisition device is provided with a first solenoid induction module, a second solenoid induction module, a third solenoid induction module, and a fourth solenoid induction module, the axis of the first solenoid induction module is arranged along a horizontal axis direction of a space rectangular coordinate system in which the underground cable is located, and the first solenoid induction module and the third solenoid induction module are located at the same height, the axis of the second solenoid induction module is arranged along a vertical axis direction of the space rectangular coordinate system in which the underground cable is located, the axis of the third solenoid induction module is arranged along a vertical axis direction of the space rectangular coordinate system in which the underground cable is located, and the axis of the fourth solenoid induction module is arranged along a vertical axis direction of the space rectangular coordinate system in which the underground cable is located; The first solenoid induction module and the second solenoid induction module are respectively used for collecting the first electromagnetic signal and the second electromagnetic signal; The third solenoid induction module is used for collecting the third electromagnetic signal; The fourth solenoid induction module is used for verifying that the underground cable is located at a reference position directly below the electromagnetic signal acquisition device; The processor is used for determining the direction of the underground cable according to the first electromagnetic signal and the third electromagnetic signal, and determining the buried depth of the underground cable according to the first electromagnetic signal, the second electromagnetic signal, the first height, and the second height.

10. A computer-readable storage medium, characterized in that, A computer readable storage medium storing a program or instructions which, when executed by a processor, enable the steps of the method for detecting the orientation and depth of an underground cable according to any one of claims 1 to 7.

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