Buried cable hunting device based on radio frequency

Abstract

The utility model provides a buried cable hunting device based on radio frequency, which is applied to the technical field of cable hunting, and comprises a main control chip, a display screen, a signal generation module, a signal detection module and an antenna, the main control chip is respectively connected with the display screen, the signal generation module and the signal detection module, the output end of the signal generation module is connected with a signal clamp, and the signal clamp is connected with the antenna. The signal clamp is connected with a to-be-detected cable, the signal detection module is connected with the antenna and used for receiving signals around the to-be-detected cable, and the display screen is used for displaying detection data and detection states. The main control chip sends a characteristic signal to the signal generation module to drive the signal generation module to generate a modulation signal, the main control chip is further used for adjusting the power of the modulation signal, and the modulation signal is injected into the cable to be detected through the signal clamp. The characteristic signal is transmitted through the frequency of the modulation signal, the penetrability of the modulation signal is utilized, the cable to be detected is used as a radiation source, and specific signals are collected around the non-electrified cable so as to achieve the purpose of detecting the trend of the cable.

Description

Technical Field

[0001] The utility model belongs to the technical field of cable line finding, and in particular relates to a buried cable line finding device based on radio frequency. Background Art

[0002] Cable is a device for transmitting electric energy or signals, usually composed of several or several groups of wires. For initial construction and renovation projects, there are often no signs during construction, so it is necessary to verify and track the actual cable route. However, the cables are buried underground or inside walls, so it is necessary to meet the inspection requirements without destroying the original environment.

[0003] For projects that have been under construction for a long time, due to the long construction time, it is possible that the existing maintenance personnel are no longer able to obtain the actual cable laying line information, and appropriate non-destructive means are also needed to inspect the lines.

[0004] In addition, when a cable fails and needs to be excavated for repair, the direction of the cable must be verified before targeted excavation to avoid trial excavation.

[0005] At present, most of the electromagnetic induction line-finding devices rely on the internal detection coil to sense the electromagnetic field generated by the conductor to achieve the purpose of line-finding. The existing devices require the cable to be powered to sense the electromagnetic field, but the actual situation is that a large number of cables are not powered during line-finding. At the same time, the electromagnetic line-finding device is also affected by the buried depth of the cable. The low frequency of 50Hz has the characteristic of poor penetration, so it is too limited in application. Utility Model Content

[0006] In view of the above-mentioned problems in the prior art, the purpose of the utility model is to provide a buried cable tracing device based on radio frequency, which transmits characteristic signals by modulating the frequency of the signal, utilizes the penetration of the modulated signal, takes the cable to be tested as the radiation source, and collects specific signals around the non-powered cable to achieve the purpose of detecting the direction of the cable.

[0007] A buried cable line-finding device based on radio frequency comprises a main control chip, a display screen, a signal generating module, a signal detecting module and an antenna, wherein the main control chip is respectively connected to the display screen, the signal generating module and the signal detecting module, the output end of the signal generating module is connected to a signal clamp, the signal clamp is connected to a cable to be tested, the signal detecting module is connected to the antenna and is used to receive signals around the cable to be tested, and the display screen is used to display detection data and detection status; the main control chip sends a characteristic signal to the signal generating module to drive the signal generating module to generate a modulation signal, and the main control chip is also used to adjust the power of the modulation signal, and the modulation signal is injected into the cable to be tested through the signal clamp.

[0008] Preferably, the characteristic signal includes a high level and a low level, and the signal generating module outputs a corresponding modulation signal according to the characteristic signal. The high frequency range of the modulation signal is 5MHz±20KHz, corresponding to the high level of the characteristic signal, and the low frequency range of the modulation signal is 800KHz±10KHz, corresponding to the low level of the characteristic signal.

[0009] Preferably, the signal generating module comprises a DAC unit, a modulation unit, a conditioning amplifier unit and a power amplifier unit, the DAC unit and the modulation unit are integrated in the processing chip U7, the CLK pin, DATA pin, LE pin, TRCTL pin and CE pin of the processing chip U7 are respectively connected to the corresponding pins of the main control chip, and are used to receive the characteristic signal sent by the main control chip; the conditioning amplifier unit comprises a chip U8, the IN1 pin of the chip U8 is connected to the FLOUT1 pin of the processing chip U7, the IN2 pin of the chip U8 is connected to the FLOUT2 pin of the processing chip U7, the NO1 pin of the chip U8 is grounded through a capacitor C41, the NO2 pin is grounded through a capacitor C42, the V+ pin of the chip U8 is connected to a parallel resistor R16 and a capacitor C43, the other end of the resistor R16 is connected to the power supply, the other end of the capacitor C43 is grounded, and the COM1 pin of the chip U8 is connected to a parallel capacitor C45 , resistor R17, the other end of the capacitor C45 is grounded, the other end of the resistor R17 is connected to the CPOUTEXT pin of the processing chip U7, a capacitor C44 is also connected between the resistor R17 and the CPOUTEXT pin of the processing chip U7, and the other end of the capacitor C44 is grounded; the power amplifier unit includes a chip U9, a VCC pin of the chip U9 is connected to a capacitor C48 and a resistor R25 in parallel, the other end of the capacitor C48 is grounded, the other end of the resistor R25 is connected to a power supply, a VTUNE pin of the chip U9 is connected to a capacitor C47 and a resistor R24 ​​in parallel, the other end of the capacitor C47 is grounded, the other end of the resistor R24 ​​is connected to a capacitor C46 and a resistor R21 in parallel, the other end of the capacitor C46 is grounded, the other end of the resistor R21 is connected to an end of the resistor R17 away from the capacitor C45, and the RFOUT pin of the chip U9 is the output end of the signal generating module, which is used to output a modulated signal.

[0010] Preferably, the processing chip U7 also includes a peripheral circuit and a control circuit, the control circuit includes a capacitor C50 connected to the FIN pin of the processing chip U7, the other end of the capacitor C50 is connected to a resistor R28, the other end of the resistor R28 is connected to resistors R26, R27, and R29, the other end of the resistor R26 is connected to the RFOUT pin of the chip U9 through the capacitor C49, the other end of the resistor R27 is grounded, and the other end of the resistor R29 is connected to the connector CN3.

[0011] Preferably, the signal detection module includes an input filter and a detector, the detector is integrated in the processing chip U7, the FSK_DV pin, FSK_D2 pin, FSK_D1 pin, and FSK_D0 pin of the processing chip U7 are respectively connected to the corresponding pins of the main control chip, and are used to send a detection signal to the main control chip; the input filter is connected to the antenna, and the input filter includes a capacitor C58, one end of the capacitor C58 is connected to the RFOUTTX pin of the processing chip U7, and the other end is connected to the connector CN5, and a parallel capacitor C65 and an inductor L7 are also connected between the capacitor C58 and the RFOUTTX pin, the other ends of the capacitor C65 and the inductor L7 are both connected to the capacitor C67, the other end of the capacitor C67 is grounded, and the inductor L7 is far away from the capacitor C5 8 is connected to a power supply, and parallel resistors R48 and R49 are also connected between the capacitor C58 and the connector CN5, and the other ends of the resistors R48 and R49 are grounded; the input filter also includes a capacitor C60, one end of the capacitor C60 is connected to the RFOUTRX pin of the processing chip U7, and the other end is connected to the connector CN4, and a parallel capacitor C66 and an inductor L4 are also connected between the capacitor C60 and the RFOUTRX pin, and the other ends of the capacitor C66 and the inductor L4 are connected to the capacitor C68, and the other end of the capacitor C68 is grounded, and the end of the inductor L4 away from the capacitor C60 is connected to the power supply, and parallel resistors R50 and R51 are also connected between the capacitor C60 and the connector CN4, and the other ends of the resistors R50 and R51 are grounded.

[0012] The beneficial effects of the utility model are as follows: the radio frequency-based buried cable finding device transmits characteristic signals through the frequency of the modulated signal, utilizes the penetration of the modulated signal, uses the cable to be tested as a radiation source, collects specific signals around the non-energized cable, and can achieve the purpose of detecting the direction of the cable without digging the ground or walls.

[0013] By adjusting the power of the modulation signal through the main control chip, the power of the modulation signal can be adjusted according to the buried depth of the cable, so that the modulation signal strength output by the signal transmitting module can be adjusted in grades, thereby improving the applicability and detection accuracy of the line-finding device. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0015] Figure 1 It is a system block diagram of the utility model;

[0016] Figure 2It is a circuit diagram of a signal generation module and a signal detection module of the utility model;

[0017] Figure 3 It is a line-finding demonstration diagram of the utility model;

[0018] Figure 4 This is a corresponding relationship diagram between the characteristic signal and the modulation signal of the utility model. DETAILED DESCRIPTION

[0019] Embodiment 1

[0020] like Figure 1 As shown, a radio frequency-based buried cable line-finding device includes a main control chip, a display screen, a signal generating module, a signal detection module and an antenna, wherein the main control chip is respectively connected to the display screen, the signal generating module and the signal detection module, and the output end of the signal generating module is connected to a signal clamp, wherein the signal clamp is a coupled signal injection clamp; the coupled signal injection clamp is connected to a cable to be tested, and is used for injecting a modulated signal output by the signal generating module into the cable to be tested.

[0021] In addition, the signal detection module is connected to the antenna for receiving signals around the cable to be tested, and the display screen is used to display detection data and detection status; the main control chip is also connected to buttons for starting, shutting down and configuring parameters of the line-finding device.

[0022] The main control chip sends a characteristic signal to the signal generating module to drive the signal generating module to generate a modulation signal. The modulation signal is adjusted in power by the main control chip, and the adjusted modulation signal is injected into the cable to be tested through the signal clamp.

[0023] The penetrability characteristics of electromagnetic waves are as follows:

[0024] The diffraction / diffraction penetration of electromagnetic waves is characterized by the fact that the microwave particles entering and exiting are not the same. At this time, the longer the wavelength and the lower the frequency, the better the penetration. This type of penetration is common in electromagnetic waves such as radio.

[0025] The same-object penetration of electromagnetic waves is characterized by the same microwave particle (such as X-rays and Y-rays) entering and exiting. At this time, the higher the frequency, the shorter the wavelength, the greater the energy, and the stronger the penetrating ability. However, the use of this type of electromagnetic wave is greatly restricted.

[0026] However, according to the principle of "wave-particle duality", the lower the frequency, the longer the wavelength, the stronger the diffraction ability, and the weaker the linear penetration ability; the higher the frequency, the shorter the wavelength, the stronger the direct radiation ability, and the stronger the linear penetration ability.

[0027] Therefore, based on the characteristics of electromagnetic waves, the selected electromagnetic waves must have a certain penetration ability and be able to be generated and detected. Therefore, the optimal frequency that can be selected is medium and high frequency electromagnetic waves. Among them, the medium frequency range is 30KHz to 3000KHz, and the high frequency range is 3MHz to 30MHz.

[0028] Since the line-finding signal needs to carry certain characteristics and avoid common interference sources, it is necessary to add certain modulation to the waveform of the signal transmitter to make it have typical characteristics. At the same time, adding corresponding demodulation at the receiving end can restore the original data before modulation.

[0029] After repeated verification, an intermediate frequency of 800KHz was selected to correspond to the modulated low-frequency signal, and a high frequency of 5MHz was selected to correspond to the modulated high-frequency signal. This can not only take into account sufficient penetration ability, but also facilitate the implementation of the solution, making the waveform easy to generate and analyze.

[0030] like Figure 1 , Figure 4 As shown, the characteristic signal includes a high level and a low level. The signal generating module outputs a corresponding modulation signal according to the characteristic signal. The high frequency range of the modulation signal is 5MHz±20KHz, corresponding to the high level of the characteristic signal, and the low frequency range of the modulation signal is 800KHz±10KHz, corresponding to the low level of the characteristic signal.

[0031] The signal generating module converts the digital information of the characteristic signal into the waveform information of the modulated signal and injects it into the cable to be tested. By utilizing the penetration of the modulated signal and taking the cable to be tested as the radiation source, the antenna collects specific signals around the non-powered cable and transmits them to the main control chip to realize the collection of specific signals, thereby obtaining the direction information of the cable to be tested and realizing the line-finding function.

[0032] Specifically, Figure 2 As shown, the signal generating module includes a DAC unit, a modulation unit, a conditioning operational amplifier unit and a power amplifier unit. The DAC unit and the modulation unit are integrated in the processing chip U7. The CLK pin, DATA pin, LE pin, TRCTL pin and CE pin of the processing chip U7 are respectively connected to the corresponding pins of the main control chip for receiving the characteristic signals sent by the main control chip.

[0033] The conditioning operational amplifier unit includes a chip U8, the IN1 pin of the chip U8 is connected to the FLOUT1 pin of the processing chip U7, the IN2 pin of the chip U8 is connected to the FLOUT2 pin of the processing chip U7, the NO1 pin of the chip U8 is grounded through a capacitor C41, the NO2 pin is grounded through a capacitor C42, the V+ pin of the chip U8 is connected to a resistor R16 and a capacitor C43 in parallel, the other end of the resistor R16 is connected to a power supply, the other end of the capacitor C43 is grounded, the COM1 pin of the chip U8 is connected to a capacitor C45 and a resistor R17 in parallel, the other end of the capacitor C45 is grounded, the other end of the resistor R17 is connected to the CPOUTEXT pin of the processing chip U7, a capacitor C44 is also connected between the resistor R17 and the CPOUTEXT pin of the processing chip U7, and the other end of the capacitor C44 is grounded.

[0034] The power amplifier unit includes a chip U9, a VCC pin of which is connected to a capacitor C48 and a resistor R25 in parallel, the other end of the capacitor C48 is grounded, and the other end of the resistor R25 is connected to a power supply, a VTUNE pin of the chip U9 is connected to a capacitor C47 and a resistor R24 ​​in parallel, the other end of the capacitor C47 is grounded, the other end of the resistor R24 ​​is connected to a capacitor C46 and a resistor R21 in parallel, the other end of the capacitor C46 is grounded, the other end of the resistor R21 is connected to an end of the resistor R17 away from the capacitor C45, and the RFOUT pin of the chip U9 is the output end of the signal generating module, which is used to output a modulated signal.

[0035] In addition, the processing chip U7 also includes a peripheral circuit and a control circuit, wherein the control circuit includes a capacitor C50 connected to the FIN pin of the processing chip U7, the other end of the capacitor C50 is connected to a resistor R28, the other end of the resistor R28 is connected to resistors R26, R27, and R29, the other end of the resistor R26 is connected to the RFOUT pin of the chip U9 through a capacitor C49, the other end of the resistor R27 is grounded, and the other end of the resistor R29 is connected to the connector CN3. The power of the modulated signal output by the signal generating module is adjusted by the control circuit, and the power of the modulated signal can be adjusted according to the buried depth of the cable to be tested, thereby improving the applicability and detection accuracy of the line-finding device.

[0036] like Figure 2 As shown, the signal detection module includes an input filter and a detector, and the detector is integrated in the processing chip U7. The FSK_DV pin, FSK_D2 pin, FSK_D1 pin, and FSK_D0 pin of the processing chip U7 are respectively connected to the corresponding pins of the main control chip for sending a detection signal to the main control chip.

[0037] The input filter is connected to the antenna, and the input filter includes a capacitor C58, one end of which is connected to the RFOUTTX pin of the processing chip U7, and the other end is connected to the connector CN5. A capacitor C65 and an inductor L7 are also connected in parallel between the capacitor C58 and the RFOUTTX pin. The other ends of the capacitor C65 and the inductor L7 are both connected to the capacitor C67. The other end of the capacitor C67 is grounded. The end of the inductor L7 away from the capacitor C58 is connected to the power supply. Resistors R48 and R49 are also connected in parallel between the capacitor C58 and the connector CN5. The other ends of the resistors R48 and R49 are both grounded.

[0038] The input filter also includes a capacitor C60, one end of which is connected to the RFOUTRX pin of the processing chip U7, and the other end is connected to the connector CN4. A capacitor C66 and an inductor L4 are connected in parallel between the capacitor C60 and the RFOUTRX pin. The other ends of the capacitor C66 and the inductor L4 are connected to a capacitor C68. The other end of the capacitor C68 is grounded. One end of the inductor L4 away from the capacitor C60 is connected to a power supply. A resistor R50 and a resistor R51 are connected in parallel between the capacitor C60 and the connector CN4. The other ends of the resistor R50 and the resistor R51 are grounded.

[0039] like Figure 3 As shown, the radio frequency-based buried cable tracking device needs to be configured with at least two devices when in use, one of which is used as a host and the remaining devices are used as slaves, and the corresponding devices are configured as host mode or slave mode, which are used for signal transmission and signal reception respectively, wherein the signal clamp of the host is connected to the cable to be tested.

[0040] Before testing, move the slave within a certain range around the host, and adjust the output power of the host so that it can stably receive signals. Then move the slave along the suspected cable laying path on the ground or wall, and determine the specific direction of the cable based on the information displayed on the display.

[0041] Specifically, according to the characteristic signal set by the main control chip, the signal generating module generates a corresponding modulation signal, and the power is adjusted through the main control chip. The adjusted modulation signal is injected into the cable to be tested through the signal clamp. The cable to be tested is used as a radiation source. The antenna collects specific signals around the non-powered cable and transmits them to the main control chip. The actual direction of the cable is determined by signal modulation and demodulation.

[0042] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A buried cable tracing device based on radio frequency, characterized in that: It includes a main control chip, a display screen, a signal generating module, a signal detecting module and an antenna, wherein the main control chip is connected to the display screen, the signal generating module and the signal detecting module respectively, the output end of the signal generating module is connected to a signal clamp, the signal clamp is connected to the cable to be tested, the signal detecting module is connected to the antenna and is used to receive signals around the cable to be tested, and the display screen is used to display detection data and detection status; The main control chip sends a characteristic signal to the signal generating module to drive the signal generating module to generate a modulation signal. The main control chip is also used to adjust the power of the modulation signal. The modulation signal is injected into the cable to be tested through the signal clamp.

2. The radio frequency based buried cable tracing device according to claim 1, characterized in that: The characteristic signal includes a high level and a low level. The signal generating module outputs a corresponding modulation signal according to the characteristic signal. The high frequency range of the modulation signal is 5MHz±20KHz, corresponding to the high level of the characteristic signal, and the low frequency range of the modulation signal is 800KHz±10KHz, corresponding to the low level of the characteristic signal.

3. The radio frequency based buried cable tracing device according to claim 1, characterized in that: The signal generation module includes a DAC unit, a modulation unit, a conditioning amplifier unit and a power amplifier unit. The DAC unit and the modulation unit are integrated in the processing chip U7. The CLK pin, DATA pin, LE pin, TRCTL pin and CE pin of the processing chip U7 are respectively connected to the corresponding pins of the main control chip to receive the characteristic signal sent by the main control chip; The conditioning operational amplifier unit includes a chip U8, an IN1 pin of the chip U8 is connected to a FLOUT1 pin of a processing chip U7, an IN2 pin of the chip U8 is connected to a FLOUT2 pin of the processing chip U7, a NO1 pin of the chip U8 is grounded via a capacitor C41, a NO2 pin is grounded via a capacitor C42, a V+ pin of the chip U8 is connected to a resistor R16 and a capacitor C43 in parallel, the other end of the resistor R16 is connected to a power supply, the other end of the capacitor C43 is grounded, a COM1 pin of the chip U8 is connected to a capacitor C45 and a resistor R17 in parallel, the other end of the capacitor C45 is grounded, the other end of the resistor R17 is connected to a CPOUTEXT pin of the processing chip U7, a capacitor C44 is further connected between the resistor R17 and the CPOUTEXT pin of the processing chip U7, and the other end of the capacitor C44 is grounded; The power amplifier unit includes a chip U9, a VCC pin of the chip U9 is connected to a capacitor C48 and a resistor R25 in parallel, the other end of the capacitor C48 is grounded, and the other end of the resistor R25 is connected to a power supply, a VTUNE pin of the chip U9 is connected to a capacitor C47 and a resistor R24 ​​in parallel, the other end of the capacitor C47 is grounded, the other end of the resistor R24 ​​is connected to a capacitor C46 and a resistor R21 in parallel, the other end of the capacitor C46 is grounded, and the other end of the resistor R21 is connected to an end of the resistor R17 away from the capacitor C45, and the RFOUT pin of the chip U9 is the output end of the signal generating module, which is used to output a modulated signal.

4. The radio frequency based buried cable tracing device according to claim 3, characterized in that: The processing chip U7 also includes a peripheral circuit and a control circuit. The control circuit includes a capacitor C50 connected to the FIN pin of the processing chip U7. The other end of the capacitor C50 is connected to a resistor R28. The other end of the resistor R28 is connected to resistors R26, R27, and R29. The other end of the resistor R26 is connected to the RFOUT pin of the chip U9 through the capacitor C49. The other end of the resistor R27 is grounded. The other end of the resistor R29 is connected to the connector CN3.

5. The radio frequency based buried cable tracing device according to claim 1, characterized in that: The signal detection module includes an input filter and a detector, the detector is integrated in the processing chip U7, and the FSK_DV pin, FSK_D2 pin, FSK_D1 pin, and FSK_D0 pin of the processing chip U7 are respectively connected to the corresponding pins of the main control chip, so as to send a detection signal to the main control chip; The input filter is connected to the antenna, and the input filter includes a capacitor C58, one end of the capacitor C58 is connected to the RFOUTTX pin of the processing chip U7, and the other end is connected to the connector CN5, and a capacitor C65 and an inductor L7 are connected in parallel between the capacitor C58 and the RFOUTTX pin, and the other ends of the capacitor C65 and the inductor L7 are connected to the capacitor C67, and the other end of the capacitor C67 is grounded, and the end of the inductor L7 away from the capacitor C58 is connected to the power supply, and a resistor R48 and a resistor R49 are connected in parallel between the capacitor C58 and the connector CN5, and the other ends of the resistor R48 and the resistor R49 are grounded; The input filter also includes a capacitor C60, one end of which is connected to the RFOUTRX pin of the processing chip U7, and the other end is connected to the connector CN4. A capacitor C66 and an inductor L4 are connected in parallel between the capacitor C60 and the RFOUTRX pin. The other ends of the capacitor C66 and the inductor L4 are connected to a capacitor C68. The other end of the capacitor C68 is grounded. One end of the inductor L4 away from the capacitor C60 is connected to a power supply. A resistor R50 and a resistor R51 are connected in parallel between the capacitor C60 and the connector CN4. The other ends of the resistor R50 and the resistor R51 are grounded.

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