Dual-frequency radio wave detection device and method

Abstract

The invention relates to the technical field of detection devices, and particularly discloses a dual-frequency radio wave detection device, which comprises two sets of independently arranged transmitting circuits, two sets of independently arranged receiving circuits, a switch switching circuit, a transmitting and receiving integrated coil, a control unit and an ADC (Analog to Digital Converter) module, the switch switching circuit is used for selectively conducting the connection between the transmitting circuit and the receiving and transmitting integrated coil or conducting the connection between the receiving circuit and the receiving and transmitting integrated coil so as to realize the switching between a transmitting mode and a receiving mode; the transmitting circuit supports the transmission of at least two high-low frequency band signals, and the transmitting circuit is an H-bridge transmitting circuit; and the receiving circuit supports receiving of signals of corresponding frequency bands. According to the invention, two sets of independent high and low frequency band transmit-receive circuits are arranged, detection can be carried out by using the strong penetration characteristic of low frequency signals and the high resolution characteristic of high frequency signals at the same time, and the technical problem that an existing single frequency band detection device is difficult to give consideration to the detection distance and the identification precision is solved. And the adaptive detection capability of different-scale structure abnormal regions is improved.

Description

Technical Field

[0001] This invention relates to the field of detection device technology, specifically to a dual-frequency radio wave detection device and method. Background Technology

[0002] Underground geological structure detection is a crucial step in ensuring the safe mining of mineral resources. Radio wave detection technology, due to its advantages of not damaging geological bodies and having a wide detection range, is widely used in the detection of structural anomalies in underground working faces. However, existing underground radio wave detection technologies still have many shortcomings and cannot meet the requirements for efficient and accurate detection. Existing detection devices mostly use single-band signals for detection, and the selection of frequency bands has inherent defects: although low-frequency signals have strong penetration capabilities and can achieve detection over long distances, their resolution is low and it is difficult to accurately locate small structural anomaly areas; high-frequency signals have higher resolution and can clearly identify small-scale anomalies, but their penetration capabilities are weak and their detection distance is limited, making it impossible to meet the dual requirements of long-distance detection and accurate identification. Meanwhile, the switching of transmission and reception modes in existing detection devices largely relies on manual operation, requiring staff to enter the tunnels to adjust equipment status or swap the positions of transceivers. This is not only cumbersome and inefficient but also poses certain safety hazards. Furthermore, existing detection methods often rely on single-frequency band detection data for inversion analysis during data processing, resulting in insufficient identification of response characteristics of geological anomalies. This can easily lead to deviations in the location of anomaly areas, affecting the reliability of the detection results. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a dual-frequency radio wave detection device and method, which solves the problems mentioned in the background section.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a dual-frequency radio wave detection device, comprising: Two independently configured transmitting circuits, receiving circuits, as well as switching circuits, transceiver coils, control units, and ADC modules; The switching circuit is used to selectively connect the transmitting circuit and the transceiver coil (disconnect the receiving circuit), or connect the receiving circuit and the transceiver coil (disconnect the transmitting circuit), thereby switching between the transmitting mode and the receiving mode. The transmitting circuit supports the transmission of at least two high- and low-frequency signals, and the transmitting circuit is an H-bridge transmitting circuit; The receiving circuit supports the reception of signals in the corresponding frequency band and is connected to the ADC module to convert the received analog signals into digital signals. The control unit uses an FPGA or DSP as the main control chip. In the transmit mode, it generates a square wave of the corresponding frequency and drives the H-bridge transmitting circuit to transmit signals through the transceiver coil. In the receive mode, it reads and processes the digital signal from the ADC module to obtain the amplitude of the wireless signal.

[0005] Preferably, the two independent transmitting and receiving circuits correspond to the low-frequency band. and high frequency band The For low-frequency signals with strong penetrating power, the It is a high-resolution, high-frequency signal.

[0006] Preferably, the switching circuit is an electronic switch, which switches the transmitting circuit and the receiving circuit through a control signal output by the control unit.

[0007] A dual-frequency radio wave detection method includes the following steps: S1: Deploy detection devices in a single underground roadway, and switch the detection devices to transmission mode via a control unit, selecting at least one high-low frequency combination. , It transmits electromagnetic wave signals of corresponding frequencies sequentially through the H-bridge transmitting circuit and the transceiver coil; S2: Another detection device is installed in the opposite roadway, switched to receiving mode, and receives the electromagnetic wave signal after it propagates through the coal and rock layer through the transceiver coil. After being processed by the receiving circuit, it is converted into a digital signal by the ADC module. The control unit reads and stores the digital signal. S3: Without swapping tunnels and equipment, switch the transmission mode and receive mode through the control unit, repeat steps S1-S2, and complete the signal transmission and reception coverage of all transmission and receiving points; S4: Based on ray tracing theory, according to the field strength formula at the receiving point Where H is the field strength at the receiving point. The initial field strength, The attenuation coefficient is... To calculate the propagation distance, calculate the low frequency separately. Corresponding attenuation coefficient and high frequency Corresponding attenuation coefficient ; S5: Calculate the dual-frequency transmission attenuation coefficient ; S6: Using the tomographic inversion method, we obtain the following results respectively. , and The corresponding tomographic inversion diagrams are used to analyze the three inversion diagrams together to determine the distribution location of the structural anomaly zone within the working face.

[0008] Preferably, the number of high and low frequency combinations in step S1 is 1-3 groups, and each group contains a low frequency signal and a high frequency signal.

[0009] Preferably, in step S3, the remote control mode is switched by the control unit, eliminating the need for personnel to enter the tunnel for operation, thus enabling rapid switching of the receiving and sending functions within a single tunnel.

[0010] Preferably, in step S6, during the comprehensive analysis, retain Long-range transmission characteristics and Its high resolution characteristics, combined with The response characteristics to geological anomalies improve the resolution of anomaly identification.

[0011] Preferably, in step S2, the received electromagnetic wave signal is filtered and amplified by the receiving circuit before being transmitted to the ADC module for analog-to-digital conversion.

[0012] This invention provides a dual-frequency radio wave detection device and method, which has the following beneficial effects: 1. Achieving a balance between long-range detection and accurate identification: By setting up two independent high- and low-frequency transceiver circuits, this invention can simultaneously utilize the strong penetration characteristics of low-frequency signals and the high-resolution characteristics of high-frequency signals to carry out detection. This solves the technical problem that existing single-frequency detection devices cannot balance detection distance and identification accuracy, and improves the adaptability of detection to structural anomaly areas of different scales.

[0013] 2. Simplified operation process and improved detection efficiency and safety: Through the coordinated action of the switch switching circuit and the control unit, the present invention can realize the automatic switching of the transmission and reception modes. There is no need for manual entry into the roadway to adjust the equipment or exchange the transmission and reception positions. This not only simplifies the operation process and shortens the detection cycle, but also avoids the working risks of workers in the complex underground environment, and improves the safety and convenience of the detection process.

[0014] 3. Improve the accuracy and reliability of anomaly zone location: The dual-frequency perspective attenuation coefficient calculation method proposed in this invention combines the attenuation coefficients of two frequency bands for comprehensive tomographic inversion analysis. Compared with the existing single-frequency band data inversion method, it can more comprehensively capture the response characteristics of geological anomalies, effectively reduce the location deviation of anomaly zones, improve the reliability of detection results, and provide more accurate geological basis for safe underground mining.

[0015] 4. Simple structure and strong adaptability: The present invention adopts an integrated transceiver coil design, which simplifies the overall structure of the device and facilitates its deployment and transportation in confined underground spaces. At the same time, the control unit uses mature FPGA or DSP chips, which have strong signal processing capabilities and stability, and can adapt to the complex electromagnetic environment and harsh working conditions underground, ensuring the stable operation of exploration work. Attached Figure Description

[0016] Figure 1 This is a diagram illustrating the radio wave perspective method of the present invention; Figure 2 This is a schematic diagram of the dual-frequency radio wave imaging device of the present invention. Detailed Implementation

[0017] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Example 1 discloses a downhole dual-frequency radio wave detection device, such as... Figure 1 As shown (this is an exemplary description; in actual patents, it can be accompanied by accompanying drawings), it includes two independently configured transmitting circuits, two independently configured receiving circuits, as well as a switching circuit, a transceiver coil, a control unit, and an ADC module. All components are electrically connected through wires to form a complete signal transmission and processing system.

[0019] The transmitting circuit is an H-bridge transmitting circuit, with two sets of transmitting circuits adapted to the low-frequency band respectively. and high frequency band ,in It is a low-frequency signal with strong penetrating power. For high-resolution high-frequency signals, each transmitting circuit can independently generate and output electromagnetic wave drive signals in the corresponding frequency band. The H-bridge structure has the characteristics of stable output power and strong driving capability, which can ensure the effective radiation of electromagnetic wave signals.

[0020] The receiving circuit and the transmitting circuit are in one-to-one correspondence, each supporting the low-frequency band. and high frequency band The signal receiving circuit integrates a filtering module and an amplification module. The filtering module is used to filter out interference signals in the complex electromagnetic environment downhole, and the amplification module is used to amplify the amplitude of the weak received signal to ensure the accuracy of subsequent signal processing. The output of the receiving circuit is electrically connected to the input of the ADC module to transmit the processed analog signal to the ADC module for analog-to-digital conversion.

[0021] The switching circuit is an electronic switch. Its input terminals are connected to the output terminals of the two sets of transmitting circuits and the input terminals of the two sets of receiving circuits, respectively. Its output terminal is connected to the transceiver coil, and its control terminal is electrically connected to the I / O interface of the control unit. Under the control of the control unit, the switching circuit selectively connects the transmitting circuit to the transceiver coil (while simultaneously disconnecting the transmitting circuit from the receiving circuit), or connects the receiving circuit to the transceiver coil (while simultaneously disconnecting the transmitting circuit from the transceiver coil), thereby switching between transmitting and receiving modes.

[0022] The integrated transceiver coil adopts a hollow coil or a coil with a magnetic core structure, possessing dual functions of signal transmission and reception. It eliminates the need for separate transmitting and receiving coils, simplifying the device structure and facilitating deployment in confined underground spaces. Its coil parameters are adapted to the low-frequency band. and high frequency band The signal characteristics ensure effective transmission and reception of signals in both frequency bands.

[0023] The control unit uses an FPGA as the main control chip (a DSP chip can also be used). The FPGA chip has the advantages of strong parallel processing capability and good real-time performance, which can meet the real-time requirements of dual-band signal transmission and reception control and data processing. The output terminal of the control unit is electrically connected to the input terminals of the two sets of transmitting circuits and the control terminal of the switching circuit. The input terminal is electrically connected to the output terminal of the ADC module. In the transmission mode, the control unit generates a square wave signal of the corresponding frequency and outputs it to the H-bridge transmitting circuit to drive the H-bridge transmitting circuit to work and transmit electromagnetic wave signals through the transceiver coil. In the reception mode, the control unit reads the digital signal output by the ADC module and analyzes the digital signal to obtain the amplitude information of the wireless signal.

[0024] The ADC module uses a high-precision analog-to-digital converter chip. Its sampling frequency and resolution are adapted to the frequency band characteristics of the received signal. It can accurately convert the analog signal transmitted by the receiving circuit into a digital signal, ensuring the integrity and accuracy of the signal data and providing a reliable data foundation for subsequent data processing.

[0025] When the device is in transmit mode, the control unit outputs a control signal to the switch switching circuit, which controls the switch switching circuit to connect the transmitting circuit and the transceiver coil, and disconnect the transmitting circuit and the receiving circuit. Then, according to the preset detection frequency band, the control unit outputs a square wave drive signal to the H-bridge transmitting circuit of the corresponding frequency band. Under the action of the square wave drive signal, the H-bridge transmitting circuit generates a current signal of the corresponding frequency band, which is converted into an electromagnetic wave signal by the transceiver coil and radiated.

[0026] When the device is in receiving mode, the control unit outputs a control signal to the switch switching circuit, which controls the switch switching circuit to connect the receiving circuit and the transceiver coil, and disconnect the transmitting circuit from the transceiver coil. The transceiver coil receives the electromagnetic wave signal propagating through the coal and rock layer, converts it into a weak voltage signal and transmits it to the receiving circuit. The receiving circuit filters out interference signals through the filtering module, amplifies the voltage signal through the amplification module, and then transmits the processed analog signal to the ADC module. The ADC module converts the analog signal into a digital signal and transmits it to the control unit. The control unit reads and stores the digital signal, completing the signal reception process.

[0027] This embodiment 2 discloses a downhole dual-frequency radio wave detection method, which is implemented based on the above-mentioned downhole dual-frequency radio wave detection device, and specifically includes the following steps: S1. Deploy the device and transmit dual-band electromagnetic wave signals: First, a detection device is deployed as a transmitter in a single underground roadway. The control unit switches the detection device to transmission mode. Based on the geological conditions of the underground detection area, 1-3 sets of high and low frequency combinations are selected. , Each high-low frequency combination contains a low-frequency signal with strong penetrating power. and a high-resolution high-frequency signal The control unit sequentially outputs square wave drive signals to the H-bridge transmitting circuit of the corresponding frequency band, driving the H-bridge transmitting circuit to work and sequentially transmitting electromagnetic wave signals corresponding to each high and low frequency combination through the transceiver coil.

[0028] S2. Receive and process electromagnetic wave signals: Another detection device is installed as a receiver in another roadway opposite the transmitting roadway. The receiver's control unit switches it to receiving mode. The transceiver coil of the receiver receives the electromagnetic wave signal after it propagates through the coal and rock strata, converts it into a voltage signal and transmits it to the receiving circuit. The receiving circuit first filters out the underground electromagnetic interference signal through the filtering module, then amplifies the voltage signal through the amplification module, and then transmits the processed analog signal to the ADC module. The ADC module converts the analog signal into a digital signal, and the receiver's control unit reads and stores the digital signal.

[0029] S3. Switch transmit / receive modes and complete signal coverage: Without requiring personnel to enter the tunnel to switch equipment or adjust its position, the control units of the two detection devices remotely output control signals to switch their respective transmission and reception modes. Steps S1-S2 are repeated, that is, the detection device that was originally the transmitter switches to the receiver, and the detection device that was originally the receiver switches to the transmitter. The remaining high and low frequency electromagnetic wave signals are transmitted and received in sequence, completing the signal transmission and reception coverage of all transmission and reception points, realizing the rapid switching of transmission and reception functions in a single tunnel, and improving detection efficiency.

[0030] S4. Calculate the attenuation coefficients for high and low frequency bands: The control unit is based on ray tracing theory and the formula for the field strength at the receiving point. (where H is the field strength at the receiving point,) The initial field strength, The attenuation coefficient is... (For propagation distance), combined with the stored digital signal data, calculate the low frequency separately. Corresponding attenuation coefficient and high frequency Corresponding attenuation coefficient The field strength H at the receiving point is obtained by analyzing the digital signal output by the ADC module, and the initial field strength is... The initial field strength of the electromagnetic wave signal emitted by the transmitter (preset parameter) is given, and the propagation distance r is the straight-line distance between the transmitter and receiver (known parameter).

[0031] S5. Calculate the dual-frequency transmission attenuation coefficient: The control unit obtains the following from step S4: and According to the formula Calculate the dual-frequency transmission attenuation coefficient ,in For low-frequency signals, These are the frequencies of high-frequency signals (all are preset parameters).

[0032] S6. Comprehensive inversion analysis to determine the location of anomaly areas: Using the tomographic inversion method, respectively for , and The corresponding dataset is used for inversion calculation to obtain... Corresponding long-range tomography inversion diagram, The corresponding high-resolution tomographic inversion plot and the dual-frequency perspective tomographic inversion plot corresponding to γ; a comprehensive analysis of the three inversion plots is performed, retaining the relevant data during the analysis. Its long-range transmission characteristics allow it to cover a wide detection area while preserving The high resolution characteristics of the γ wave are used to accurately identify small-scale anomalies. Combined with the response characteristics of γ waves to geological anomalies, the shortcomings of single-band inversion are made up for, the resolution of anomaly identification is improved, and the distribution location of structural anomaly zones within the working face is finally determined.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-frequency radio wave detection device, characterized in that, include: Two independently configured transmitting circuits, receiving circuits, as well as switching circuits, transceiver coils, control units, and ADC modules; The switching circuit is used to selectively connect the transmitting circuit and the transceiver coil, or connect the receiving circuit and the transceiver coil, to achieve switching between the transmitting mode and the receiving mode. The transmitting circuit supports the transmission of at least two high- and low-frequency signals, and the transmitting circuit is an H-bridge transmitting circuit; The receiving circuit supports the reception of signals in the corresponding frequency band and is connected to the ADC module to convert the received analog signals into digital signals. The control unit uses an FPGA or DSP as the main control chip. In the transmit mode, it generates a square wave of the corresponding frequency and drives the H-bridge transmitting circuit to transmit signals through the transceiver coil. In the receive mode, it reads and processes the digital signal from the ADC module to obtain the amplitude of the wireless signal.

2. The dual-frequency radio wave detection device according to claim 1, characterized in that, The two independent transmitting and receiving circuits correspond to the low-frequency band, respectively. and high frequency band The For low-frequency signals with strong penetrating power, the It is a high-resolution, high-frequency signal.

3. The dual-frequency radio wave detection device according to claim 2, characterized in that, The switching circuit is an electronic switch, which switches the transmitting circuit and the receiving circuit through the control signal output by the control unit.

4. A dual-frequency radio wave detection method, applied in a dual-frequency radio wave detection device as described in claim 3, characterized in that, Includes the following steps: S1: Deploy detection devices in a single underground roadway, and switch the detection devices to transmission mode via a control unit, selecting at least one high-low frequency combination. , It transmits electromagnetic wave signals of corresponding frequencies sequentially through the H-bridge transmitting circuit and the transceiver coil; S2: Another detection device is installed in the opposite roadway, switched to receiving mode, and receives the electromagnetic wave signal after it propagates through the coal and rock layer through the transceiver coil. After being processed by the receiving circuit, it is converted into a digital signal by the ADC module. The control unit reads and stores the digital signal. S3: Without swapping tunnels and equipment, switch the transmission mode and receive mode through the control unit, repeat steps S1-S2, and complete the signal transmission and reception coverage of all transmission and receiving points; S4: Based on ray tracing theory, according to the field strength formula at the receiving point Where H is the field strength at the receiving point. The initial field strength, The attenuation coefficient is... To calculate the propagation distance, calculate the low frequency separately. Corresponding attenuation coefficient and high frequency Corresponding attenuation coefficient ; S5: Calculate the dual-frequency transmission attenuation coefficient ; S6: Using the tomographic inversion method, we obtain the following results respectively. , and The corresponding tomographic inversion diagrams are used to analyze the three inversion diagrams together to determine the distribution location of the structural anomaly zone within the working face.

5. The dual-frequency radio wave detection method according to claim 4, characterized in that, The number of high and low frequency combinations in step S1 is 1-3 groups, and each group contains a low frequency signal and a high frequency signal.

6. The dual-frequency radio wave detection method according to claim 5, characterized in that, In step S3, the remote control mode is switched by the control unit, eliminating the need for personnel to enter the tunnel to operate, thus enabling rapid switching of the receiving and sending functions within a single tunnel.

7. The dual-frequency radio wave detection method according to claim 6, characterized in that, In step S6, during the comprehensive analysis, retain Long-range transmission characteristics and Its high resolution characteristics, combined with The response characteristics to geological anomalies improve the resolution of anomaly identification.

8. The dual-frequency radio wave detection method according to claim 7, characterized in that, In step S2, the received electromagnetic wave signal is filtered and amplified by the receiving circuit before being transmitted to the ADC module for analog-to-digital conversion.

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