Buried cable path and depth detection system

Abstract

The invention, which relates to the technical field of cable path detection, discloses a buried cable path and depth detection system comprising a transmitter and a receiver. The transmitter can selectively transmit a test signal of 50Hz-5kHz and inject the test signal into a cable in three different signal injection modes (a direct connection line, a transmitting coil and a coupling clamp). The receiver can select an automatic mode and a manual mode to realize buried cable path and depth detection work. According to the buried cable path and depth detection system, an automatic mode and a manual mode can be selected according to different use scenes, the path and depth of the buried cable are measured, and the accuracy and convenience of buried cable information detection are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of buried cable path and depth detection, and particularly relates to an underground cable path detection device. Background Art

[0002] In power and communication engineering, in order to ensure the normal operation of buried cables, the maintenance and management of cables are crucial. However, due to incomplete or lost cable ledger information, especially for old cables, the specific route and burial depth of the cables are often difficult to accurately determine. Therefore, during cable relocation, fault troubleshooting, and daily maintenance, cable path and depth detection equipment is required.

[0003] The basic principle of a cable path detector is to use five detection coils placed in specific positions to sense the electromagnetic field caused by the alternating current loaded on the cable to be detected. When performing path detection, a transmitter is needed to transmit a specific frequency signal to the cable, and a receiver is used for reception.

[0004] Existing cable path detectors require manual pushing of the receiving device along the cable path, resulting in low detection efficiency. Especially when detecting a large area or a long path, the workload of manually pushing the device is extremely large. In narrow spaces or complex terrain environments, such as holes, dense pipeline scenarios, etc., personnel and equipment cannot pass through, making it difficult to conduct detection work and limiting the detection coverage. Most detection devices can only provide a single operation mode, and users need to manually adjust and calibrate the device, increasing the difficulty of detection operations and also limiting the applicable scenarios of the device. To address the above problems, there is an urgent need for a cable path and depth detection system that can automatically detect and adapt to complex environments to improve detection accuracy and operation convenience, reduce labor costs, and enhance the applicability of the device. Summary of the Invention

[0005] The present invention aims to provide a buried cable path and depth detection system that can effectively solve the problems of low detection efficiency, low accuracy, complex operation, and poor adaptability to complex terrain in the prior art. By combining automatic and manual working modes, the present invention can improve the efficiency and accuracy of buried cable detection and adapt to various complex application scenarios. The main technical solution of the present invention provides a complete set of underground cable path and depth detection devices ( Figure 1 ), and the device includes a transmitter ( Figure 2 ) and a receiver ( Figure 3 ).

[0006] The present invention solves the above technical problems through the following technical means: an underground cable path and depth detection device, the main body of the device includes a transmitter and a receiver; the transmitter generates a high-power specific frequency electrical signal and injects it into the cable to be measured through different injection methods; the receiver receives the magnetic field signal generated by this electrical signal for signal processing and calculation to obtain information such as the cable path position and depth. The receiver supports automatic mode and manual mode; in the automatic mode, the receiver automatically moves along the cable path through the built-in motor and servo, without human intervention; in the manual mode, the operator manually pushes the vehicle to complete the detection work according to the prompts of the receiver.

[0007] The so-called transmitter ( Figure 2 ) is controlled by the main controller to control the amplitude and frequency of the signal generated by the signal generation module, and at the same time controls the LCD screen to display output methods, output power, signal amplitude frequency and other information; the keys can adjust the required output methods, output power, signal amplitude frequency, and finally these functions are realized by the main controller; the signal generation module generates corresponding signals and enters the power amplification module to amplify the signals; the amplified signals can be injected into the cable to be measured in three ways, direct wire injection, transmitting coil coupling injection, and coupling clamp injection; the power supply can supply power to each module.

[0008] The receiver ( Figure 3 ) converts the changing magnetic field signal into an electrical signal by the receiving coil, and then the signal acquisition module acquires information such as the frequency, amplitude, and waveform of the electrical signal; the AD module converts the continuous signal waveform into a digital signal; the filter amplification module filters out interference signals and amplifies them; the main controller calculates the processed signal to obtain information such as the cable path position and depth, and then issues instructions on the moving angle and speed of the servo and the motor according to this information to achieve the automatic detection function. The main controller can also realize the human-computer interaction function; the GPS module records the cable path and depth information; the Bluetooth module realizes the information transceiver function between the receiver and the upper computer; the human-computer interaction gives audio prompts for left and right movement and the LCD screen displays real-time information, and can also adjust the working mode and other functions through the keys. Brief Description of the Drawings

[0009] Figure 1 Schematic diagram of the appearance structure and composition of the entire experimental device system of the present invention;

[0010] Figure 2 Schematic diagram of the appearance structure and composition of the transmitter of the experimental device system of the present invention;

[0011] Figure 3 Schematic diagram of the appearance structure and composition of the receiver of the experimental device system of the present invention;

[0012] Figure 4 Structural diagram of the detailed dimensions and placement positions of the upper view of the coil of the experimental device of the present invention;

[0013] Figure 5 Structural diagram of the detailed dimensions and placement positions of the coil in the experimental device of the present invention in the front view;

[0014] Figure 6 Schematic diagram of the transmitter process in the experimental device system of the present invention;

[0015] Figure 7 Schematic diagram of the receiver process in the experimental device system of the present invention. Specific implementation manners

[0016] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described below with reference to the accompanying drawings:

[0017] Figure 1 This is a schematic diagram of the appearance of the entire experimental device of the present invention, including a transmitter and a receiver; the staff installs the transmitter at the head end of the cable, selects the signal injection method, power, and frequency, and injects a high-power specific-frequency electrical signal into the cable; on the other side, the staff uses the receiver to receive the magnetic field signal, calculates the cable path and depth in real time, and continues to detect along the cable path by moving, repeating in a cycle to complete the overall detection work.

[0018] Figure 2 and Figure 6 This is a schematic diagram of the appearance structure and composition of the transmitter in the experimental device of the present invention and a schematic diagram of the transmitter process principle; the main controller can select an ARM (Advanced RISC Machines) chip such as the LPC1769 of NXP Company to control the signal generator to output waveforms of corresponding frequencies; the signal generator can use DDS (Direct Digital Synthesizer) technology, and the programmable waveform generator AD9833 of ADI Company can be selected to generate the modulation signal and high-frequency carrier signal required for PWM modulation; the power amplification module can adopt class D power amplification design to amplify the power of the PWM signal and use a low-pass filter to restore it to the modulated signal with amplified power; the transmitting coil can induce the signal into the buried cable in the form of electromagnetic waves. When the transmitter switches to the direct connection mode or the clamp mode, a signal is applied to the buried cable through a direct wire or a coupling clamp; the liquid crystal screen is used to display information such as the frequency and power of the currently output signal in real time; the buttons are mainly responsible for switching the frequency and power of the output signal.

[0019] Figure 3 and Figure 7They are respectively the schematic diagram of the appearance structure and composition of the receiver of the experimental device of the present invention and the schematic diagram of the receiver process principle; the receiving coil can adopt a copper wire with a diameter of 1 mm, and the spiral coil winding method is adopted, with a diameter of 70 mm and a winding length of 150 mm. The coil converts the magnetic field signal above the cable into an induced electromotive force; the signal acquisition, AD conversion, and filter amplification module can be regarded as a whole to process the signal of the induced electromotive force. The core device of the circuit can adopt the operational amplifier ADA4841 of TI Company to filter and amplify the weak signal, and the AD conversion chip can adopt AK4552 of AKM Company of Japan for analog-to-digital conversion; the processed signal is transmitted to the main controller, and the main controller can adopt the STM32F103C8T6 chip; the main controller compares the magnitudes of the induced electromotive forces of coils 14 and 15 to determine the cable path position; calculates the induced electromotive forces of coils 11 and 12 to determine the cable depth; then issues direction and speed commands (usually PWM waves) to drive the servo motor to move; at the same time, communicates with the upper computer through the Bluetooth module and records the path data through the GPS module; the display screen displays information such as the path depth in real time.

[0020] Figure 4 and Figure 5 It is the schematic diagram of the appearance structure and placement position of the receiver coil of the experimental device of the present invention; there are a total of 5 coils, all of which adopt a spiral coil winding method with a diameter of 70 mm and a winding length of 150 mm; coils 11 and 12 are placed horizontally, coil 11 is on the top, coil 12 is on the bottom, and the center vertical distance is 100 mm; coil 13 is placed vertically and is located in the middle; coils 14 and 15 are placed horizontally and are symmetrically distributed on both sides, and the center horizontal distance is 150 mm; an electrical signal is injected into the cable by the transmitter. The cable is equivalent to a current-carrying wire. According to Ampere's law, a current-carrying wire generates a magnetic field; first, coils 14 and 15 convert the horizontal magnetic field signal above the cable into an induced electromotive force. Because the farther the coil is from the cable, the smaller the induced electromotive force generated. If the induced electromotive force of coil 14 is greater than the induced electromotive force of coil 15, it means that coil 14 is closer to the cable. At this time, the receiver is on the right side of the cable, and the receiver should move left to return to directly above the cable. On the contrary, it means that the receiver is on the left side of the cable, and the receiver should move right to return to directly above the cable. Thus, the cable path detection function is realized; coil 13 converts the vertical magnetic field signal above the cable into an induced electromotive force. When the receiver is directly above the cable, the induced electromotive force of coil 13 is theoretically 0, which is the minimum value. The function of coil 13 is to verify that the receiver is directly above the cable and verify whether the cable path detection is correct; coils 11 and 12 convert the horizontal magnetic field signal above the cable into an induced electromotive force. When the receiver is determined to be directly above the cable, the cable burial depth can be calculated by a specific algorithm using the numerical values of the induced electromotive forces of coils 11 and 12.

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Obviously, the described functions are part of the functions of the present invention, rather than all the functions. All other usage methods obtained by those of ordinary skill in the art based on the functions in the present invention without creative efforts fall within the protection scope of the present invention.

[0022] Automatic mode

[0023] The automatic detection mode of the buried cable path and depth detection device is described in this embodiment. First, through the cooperation of the transmitter keys and the LCD screen, select to inject a set frequency signal (such as 1 kHz) into the cable to be detected. Then, through the human-machine interface of the receiver, select the automatic detection mode, the detection signal frequency (the same as the previous setting, 1 kHz), the detection speed, and retract the pull rod. Place the receiver above the starting end of the buried cable, select start, and the receiver will automatically detect along the buried cable path at the set speed, and record the detection results through the GPS function or communicate with the host computer via Bluetooth.

[0024] Manual mode

[0025] The manual detection mode of the buried cable path and depth detection device is described in this embodiment. First, through the cooperation of the transmitter keys and the LCD screen, select to inject a set frequency signal (such as 1 kHz) into the cable to be detected. Then, through the human-machine interface of the receiver, select the manual detection mode, the detection signal frequency (the same as the previous setting, 1 kHz), and pull out the folding pull rod. Place the receiver above the starting end of the buried cable, select start, and the receiver screen will display in real time whether to move left or right and produce a prompt sound. The staff only needs to push the pull rod by hand and complete the detection of the buried cable path according to the audio prompt.

[0026] Regarding the usage scenarios and selection of the automatic mode and the manual mode, the manual mode is suitable for precise path detection in a small range and short distance. At this time, the detection speed is relatively slow, but the cable path can be detected more accurately and corrected in real time. The automatic mode is suitable for detecting cable paths over a large range and long distance, saving labor costs and having a fast detection speed. However, it may also cause relatively inaccurate detection. At the same time, because the receiver is small in size, it can pass through narrow areas such as holes and complete the detection work in specific narrow environments. According to different usage scenarios, detection accuracy requirements, and distances, select different working modes, and the two working modes can cooperate with each other to better complete the cable path detection work.

[0027] Regarding the selection of the injection signal of the transmitter, usually the power of the injection signal is pulled to the maximum, the current in the cable will reach the maximum, the alternating magnetic field and the induced electromotive force of the receiver receiving coil will be the largest, and the stronger the received electrical signal, the more accurate the detection; the higher the frequency of the injection signal, the greater the change in the magnetic flux of the receiving coil, and the greater the induced electromotive force, and the stronger the received electrical signal, the more accurate the detection. However, the attenuation of high-frequency signals in long-distance cables is more obvious and not conducive to detection. Therefore, specific problems should be analyzed specifically, and the injection signal frequency should be selected in combination with different scenarios. The injection signal frequency is usually around 1 kHz.

[0028] Regarding the selection of the injection method of the transmitter, usually the direct connection line is directly used to inject into the cable. There are large injection attenuation and signal distortion in both the transmitting coil and the coupling caliper methods, which are not conducive to detection; when encountering the occasion of non-contact injection, the transmitting coil and the coupling caliper are more suitable. These two methods do not need to be directly connected to the circuit and are safer; selecting the injection signal method in combination with different scenarios can better complete the detection work.

[0029] Regarding the cable depth detection method, there is the following formula: h is the distance from the 12th coil to the cable, d is the distance from the 12th coil to the 11th coil, ε4 is the induced electromotive force generated by the 11th coil, and ε3 is the induced electromotive force generated by the 12th coil. Subtracting the distance from the 12th coil to the ground from h is the depth of the cable.

Claims

1. An underground cable path and depth detection system (Figure 1), which is used to measure the path and depth of underground cables in an unknown natural environment, is characterized in that It consists of a transmitter (Figure 2) and a receiver (Figure 3); The said transmitter (Figure 2) consists of a main controller (1), a signal generation module (3), a power amplification module (4), a boost power supply (2), a power supply circuit, an LCD screen (5), a button, an output line (6), a transmitting coil (8), and a coupling clamp (7); the main controller (1) controls the signal generator to output waveforms of corresponding frequencies; the signal generation module (4) generates the modulation signals and high-frequency carrier signals required for PWM (Pulse Width Modulation) modulation; the power amplification module (4) amplifies the power of the PWM signal and then restores it to the power-amplified modulation signal through a low-pass filter; the output line (6), the transmitting coil (8), and the coupling clamp (7) are three different injection methods to inject the power-amplified modulation signal into the head end of the cable to be measured; the boost power supply (2) generates different voltages through the power supply circuit to supply power to the LCD screen (5), the main controller (1), the signal generation module (3), and the power amplification module (4); the LCD screen (5) displays information such as the frequency and power of the current output signal in real time; the button is used to switch the frequency and power of the output signal; The said receiver (Figure 3) consists of receiving coils (11, 12, 13, 14, 15), a signal acquisition module (1), an AD conversion module (2), a filtering and amplification module (4), a main controller (8), a power supply (3), a servo (7), a motor (9), Bluetooth (6), GPS (10), a button (17), an LCD screen (16), and an audio prompt module (18). The receiving coils (11, 12, 13, 14, 15) convert the electromagnetic signals generated by the buried cable into induced electromotive forces; the signal acquisition module (1) acquires the induced electromotive force signals in the coils; the AD conversion module (2) converts the analog signals into digital signals; the filtering and amplification module (4) filters and amplifies the digital signals; the main controller (8) calculates the digital signals to obtain information such as the cable depth and position, and at the same time generates drive control signals for the servo (7) and the motor (9), and connects to the human-machine interaction (5) interface to provide information such as menus; the LCD screen (16) is used to display interfaces such as the working frequency of the receiver, depth information, and path indication; the button (17) switches the working mode; the audio module (18) gives direction prompts; the servo (7) and the motor (9) provide direction and power for the device to travel along the cable path; Bluetooth (6) provides remote interaction functions; GPS (10) records information such as the moving path.

2. The buried cable path and depth detection system according to claim 1, wherein In the receiver, the number of the receiving coils (Figures 4 and 5) is 5. Coils (11) and (12) are horizontally placed, with coil (11) on top and coil (12) at the bottom, and the vertical distance between their centers is 100 mm. Coil (13) is vertically placed at the center of the receiver. Coils (14) and (15) are horizontally placed and symmetric about the midline of the receiver, and the horizontal distance between their centers is 150 mm. The left and right positions of the cable path are judged by coils (14) and (15), the vertical depth of the cable is calculated by coils (11) and (12), and coil (13) is used to verify whether the receiver is directly above the cable.

3. The buried cable path and depth detection system according to claim 1, wherein The receiver can freely select the manual mode and the automatic mode. In the automatic mode, the device automatically detects the cable path, while in the manual mode, the staff needs to complete the cable path detection according to the prompts.

4. The buried cable path and depth detection system according to claim 1, characterized in that Regarding the cable depth detection method, there is the following formula: h is the distance from the No. 12 coil to the cable, d is the distance from the No. 12 coil to the No. 11 coil, ε4 is the induced electromotive force generated by the No. 11 coil, ε3 is the induced electromotive force generated by the No. 12 coil, and subtracting the distance from the No. 12 coil to the ground from h gives the depth of the cable.

5. The buried cable path and depth detection system according to claim 1, characterized in that, The circular flat shell enables the receiving coil to move smoothly close to the ground and get closer to the cable, better receiving electromagnetic signals. Moreover, the circular flat shell can complete the cable path detection through narrow environments such as holes. The retractable pusher is more convenient to move forward along the detection path in the manual mode and can also retract to save space in the automatic mode.

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