Power cable fault in-trench positioning system and method based on UWB, sound and magnetic flux

Abstract

The invention discloses a power cable fault in-trench positioning system based on UWB, sound and magnetic flux. The power cable fault in-trench positioning system comprises a handheld measuring instrument and two detection rods. Each detection rod is arranged above the power cable and periodically broadcasts a radio signal carrying a self ID number and a timestamp to the handheld measuring instrument; and after a time synchronization signal is periodically sent to the other detection rod and time synchronization is confirmed, if a measurement instruction issued by the handheld measurement instrument is received, first time for initially measuring the magnetic field signal of the power cable and second time for initially measuring the sound signal of the fault point are fed back to the handheld measurement instrument; the handheld measuring instrument obtains the distance between the two detection rods based on the radio signals of the two detection rods, and positions the distances from the two detection rods to the fault point by combining the first time and the second time fed back by the two detection rods. The method has the advantages of being good in stability, high in positioning precision, high in positioning speed and the like, and manual troubleshooting and trench digging can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a system and method for locating a power cable fault in a trench based on UWB, sound and magnetic flux. Background Art

[0002] Power cables are an important part of the power system and an important guarantee for the development of the modern national economy and people's lives. With the expansion of urbanization and the increasing demand for industrial electricity, the scale of power cable laying has become increasingly large and complex. In the huge power transmission network, a considerable proportion of power cables are buried or in trenches, and failures are inevitable during long-term use. Even if there are regular safety inspections to minimize the probability of cable failures, the fault location investigation and emergency repair work when the cable fails will still bring considerable manpower and time costs to the power supply and distribution units, and will also cause great inconvenience and economic losses to surrounding factories and residents.

[0003] At present, the current method of cable fault detection is still mainly based on the primitive method of manually digging trenches to check one by one. Even with the support of more advanced devices such as sound identification and point finding, it is impossible to quickly and accurately find the fault point of the faulty cable. In particular, the environment in which buried power cables are located is relatively complex, which makes cable fault detection and positioning relatively difficult.

[0004] Therefore, there is an urgent need for a power cable fault locating method with good stability, high positioning accuracy and fast positioning speed, which can not only reduce the purpose of manpower investigation and trench digging, but also has social practical significance and engineering practical value. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a system and method for locating power cable faults in trenches based on UWB, sound and magnetic flux, which has the advantages of good stability, high positioning accuracy and fast positioning speed. It can not only reduce the manpower for investigation and trench digging, but also has social and practical significance and engineering practical value.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a positioning system for positioning a power cable fault trench based on UWB, sound and magnetic flux, including a handheld measuring instrument and two detection rods connected thereto respectively; wherein, Each of the detection rods is placed above a designated power cable, and is used to periodically broadcast a radio signal carrying its own ID number and timestamp to the handheld measuring instrument; and periodically send a time synchronization signal to another detection rod, and after confirming that time synchronization with the other detection rod is achieved, if a measurement instruction issued by the handheld measuring instrument is received, the first time of the magnetic field signal generated by the power cable initially measured is fed back to the handheld measuring instrument, and the second time of the acoustic signal sent by the fault point initially measured is fed back to the handheld measuring instrument; The handheld measuring instrument is used to obtain the distance between the two detection rods based on the radio signals broadcast by the two detection rods, and locate the distances from the two detection rods to the fault point in combination with the first time and the second time fed back by the two detection rods; wherein the distance from each detection rod to the fault point is obtained by first dividing the obtained distance between the two detection rods by the absolute value of the time difference formed between the second times of the two detection rods to obtain the propagation speed of the acoustic signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference formed between the first time and the second time.

[0007] Each of the detection rods includes a demodulator and a first UWB module, a first wireless module, a LORA module, a magnetic flux sensor and a BSS microphone connected thereto; the handheld measuring instrument includes a mainboard and a second UWB module, a second wireless module and a positioning calculation module connected thereto; The first UWB module of each of the detection rods establishes communication with the second UWB module of the handheld measuring instrument, and is used to periodically broadcast a radio signal carrying its own ID number and timestamp to the second UWB module of the handheld measuring instrument; The first wireless module of each of the detection rods establishes communication with the second wireless module of the handheld measuring instrument, and is used for data transmission and interaction with the handheld measuring instrument; The LORA module of each detection rod establishes communication with the LORA module of another detection rod, and is used to periodically send a time synchronization signal to the LORA module of another detection rod based on the synchronization period preset by the demodulator to achieve time synchronization; The magnetic flux sensor of each of the detection rods is used to start measurement synchronously with the BSS microphone carried by itself based on the measurement instruction of the handheld measuring instrument demodulated by the demodulator, and periodically sense the magnetic field signal generated by the power cable in combination with the first acquisition cycle preset by the demodulator, and further feed back the first time of the initial sensing of the magnetic field signal generated by the power cable to the handheld measuring instrument; The BSS microphone of each of the detection rods is used to start measurement synchronously with the magnetic flux sensor carried by itself based on the measurement instruction of the handheld measuring instrument demodulated by the demodulator, and periodically measure the acoustic signal sent by the fault point in combination with the second acquisition cycle preset by the demodulator, and further feed back the second time from the initial measurement to the acoustic signal sent by the fault point to the handheld measuring instrument; The second UWB module of the handheld measuring instrument is used to periodically receive the radio signal broadcasted by each of the detection rods and carrying its own ID number and time stamp; The second wireless module of the handheld measuring instrument is used to receive the data transmitted by each of the detection rods and to exchange data with each of the detection rods; The positioning calculation module of the handheld measuring instrument is used to obtain the distance between the two detection rods based on the radio signals broadcast by the two detection rods, and locate the distances from the two detection rods to the fault point respectively in combination with the first time and the second time fed back by the two detection rods; The mainboard of the handheld measuring instrument is used to synchronously generate measurement instructions for the two detection rods based on user instructions and forward them by the second wireless module; and to extract the ID number and timestamp of each detection rod from the radio signal broadcast by each detection rod and send them to the positioning calculation module.

[0008] Each of the detection rods comprises a handle portion, a straight rod and a measuring portion; The straight rod is in the shape of a hollow tube, with the handle installed on the top and the measuring part installed on the bottom, and a battery rod for providing direct current to all modules and components is arranged inside the tube; The first UWB module, the first wireless module, the LORA module and the RSS acoustic sensor are arranged inside the handle; The measuring part is a hollow cylinder in a sealed structure, and the demodulator, the magnetic flux sensor and the BSS microphone are arranged inside the measuring part.

[0009] Wherein, each of the detection rods also includes a data interface arranged outside the handle; wherein, the data interface is connected to the demodulator, which includes a serial port, a USB interface and a type-c interface.

[0010] Wherein, each of the detection rods further includes an indicator light arranged outside the handle portion; wherein, the indicator light is connected to the demodulator to display a working status.

[0011] Wherein, each of the detection rods further comprises a level meter arranged outside the measuring part; wherein, the level meter is used to measure whether it reaches a balanced state when placed above the power cable.

[0012] Wherein, the handle part, the straight rod and the measuring part of each detection rod are made of metal and plastic.

[0013] Wherein, the handheld measuring instrument also includes a liquid crystal touch screen connected to the main board; wherein, the liquid crystal touch screen is used for inputting and displaying user commands, and displaying the calculation results of the positioning calculation module; wherein, the calculation results include the distances from the two detection rods to the fault point respectively, the spacing between the two detection rods, the propagation speed of the acoustic signal in the power cable, the time difference formed between the second times of the two detection rods, and the time difference formed between the first time and the second time of each detection rod.

[0014] The embodiment of the present invention further provides a method for locating a power cable fault in a trench based on UWB, sound and magnetic flux, which is implemented on the aforementioned power cable fault locating system based on UWB, sound and magnetic flux, and the method comprises the following steps: When the two detection rods are randomly placed above the designated power cable, they periodically send time synchronization signals between them and periodically broadcast radio signals carrying their own ID numbers and timestamps to the handheld measuring instrument. After confirming the time synchronization between the two, if a measurement instruction issued by the handheld measuring instrument is received, the first time of each initially measuring the magnetic field signal generated by the power cable is fed back to the handheld measuring instrument, and the second time of each initially measuring the acoustic signal sent by the fault point is fed back to the handheld measuring instrument. The handheld measuring instrument receives the radio signals broadcast by the two detection rods, and based on the radio signals broadcast by the two detection rods, obtains the distance between the two detection rods, and further locates the distances from the two detection rods to the fault point in combination with the first time and the second time fed back by the two detection rods; wherein the distance from each detection rod to the fault point is obtained by first dividing the obtained distance between the two detection rods by the absolute value of the time difference formed between the second times of the two detection rods to obtain the propagation speed of the acoustic signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference formed by the first time and the second time.

[0015] Wherein, the method further comprises: According to the located distances from the two detection rods to the fault point, the first UWB modules preset on the two detection rods are used to locate and navigate to the fault point in real time.

[0016] Implementing the embodiments of the present invention has the following beneficial effects: The present invention obtains the distance between the two detection rods through a handheld measuring instrument according to the radio signals broadcast by the two detection rods and carrying their own ID numbers and timestamps, and further combines the first time when the two detection rods initially measure the magnetic field signal generated by the power cable and the second time when the sound signal sent by the fault point is initially measured, so as to quickly locate the distances from the two detection rods to the fault point respectively, thereby having the advantages of good stability, high positioning accuracy and fast positioning speed, etc., which can not only achieve the purpose of reducing manpower investigation and trench excavation, but also has social practical significance and engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0018] Figure 1 A schematic diagram of the structure of a power cable fault trench positioning system based on UWB, sound and magnetic flux provided by an embodiment of the present invention; Figure 2 An overall functional framework diagram of a power cable fault trench positioning system based on UWB, sound and magnetic flux provided by an embodiment of the present invention; Figure 3 A planar structural diagram of a single detection rod in a power cable fault trench positioning system based on UWB, sound and magnetic flux provided by an embodiment of the present invention; Figure 4 A schematic diagram of an application scenario of a power cable fault trench positioning system based on UWB, sound and magnetic flux provided by an embodiment of the present invention; Figure 5 A flow chart of a method for locating a power cable fault in a trench based on UWB, sound and magnetic flux is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] like Figure 1 As shown, in an embodiment of the present invention, a power cable fault trench positioning system based on UWB, sound and magnetic flux is proposed, comprising a handheld measuring instrument 2 and two detection rods 1 connected thereto respectively; wherein, Each probe rod 1 is placed above a designated power cable L, and is used to periodically (e.g., once every 2S) broadcast a radio signal carrying its own ID number and timestamp to a handheld measuring instrument 2; and periodically (e.g., once every 1min) send a time synchronization signal to another probe rod, and after confirming that time synchronization with another probe rod is achieved, if a measurement instruction from the handheld measuring instrument 2 is received, the first time of the magnetic field signal generated by the power cable L initially measured is fed back to the handheld measuring instrument 2, and the second time of the acoustic signal sent by the fault point initially measured is fed back to the handheld measuring instrument 2; The handheld measuring instrument 2 is used to obtain the distance between the two detection rods 1 based on the radio signals broadcast by the two detection rods 1, and locate the distances from the two detection rods 1 to the fault point in combination with the first time and the second time fed back by the two detection rods 1; wherein the distance from each detection rod 1 to the fault point is obtained by first dividing the obtained distance between the two detection rods 1 by the absolute value of the time difference formed between the second times of the two detection rods 1 to obtain the propagation speed of the acoustic signal in the power cable L, and then multiplying the obtained propagation speed by the absolute value of the time difference formed by the first time and the second time.

[0021] At this time, if Figure 2 As shown, each probe rod 1 includes a demodulator 11 and a first UWB module 12 connected thereto, a first wireless module 13, a LORA module 14, a magnetic flux sensor 15 and a BSS microphone 16; the handheld measuring instrument 2 includes a mainboard 21 and a second UWB module 22 connected thereto, a second wireless module 23 and a positioning calculation module 24; wherein, The first UWB module 12 of each detection rod 1 establishes communication 22 with the second UWB module of the handheld measuring instrument 2, and is used to periodically (e.g., once every 2S) broadcast a radio signal carrying its own ID number and timestamp to the second UWB module 22 of the handheld measuring instrument 2; the first wireless module 13 of each detection rod 1 establishes communication with the second wireless module 23 of the handheld measuring instrument 2, and is used to transmit and interact data with the handheld measuring instrument 2; the LORA module 14 of each detection rod 1 establishes communication with the LORA module 14 of another detection rod 1, and is used to periodically (e.g., once every 1min) send a time synchronization signal to the LORA module 14 of another detection rod 1 based on the synchronization period preset by the demodulator 11 to achieve time synchronization; the magnetic flux sensor 15 of each detection rod 1 is used to send a time synchronization signal to the LORA module 14 of another detection rod 1 based on the magnetic flux sensor demodulated by the demodulator 11 The measuring instruction of the handheld measuring instrument 2 starts the measurement synchronously with the BSS microphone 16 carried by itself, and combines with the first acquisition cycle preset by the demodulator 11 to periodically (e.g., once every 2S) sense the magnetic field signal generated by the power cable L, and further feeds back the first time of the initial induction of the magnetic field signal generated by the power cable L to the handheld measuring instrument 2 through the demodulator 11 by the first wireless module 13; the BSS microphone 16 of each detection rod 1 is used to start the measurement synchronously with the magnetic flux sensor 15 carried by itself based on the measuring instruction of the handheld measuring instrument 2 demodulated by the demodulator 11, and combines with the second acquisition cycle preset by the demodulator 11 to periodically (e.g., once every 2S) measure the acoustic signal sent by the fault point, and further feeds back the second time of the acoustic signal sent from the initial measurement to the fault point to the handheld measuring instrument through the demodulator 11 by the first wireless module 13; The second UWB module 22 of the handheld measuring instrument 2 is used to periodically receive the radio signal broadcast by each detection rod 1 and carrying its own ID number and timestamp; the second wireless module 23 of the handheld measuring instrument 2 is used to receive the data transmitted by each detection rod 1 and to exchange data with each detection rod 1; the positioning calculation module 24 of the handheld measuring instrument 2 is used to obtain the distance between the two detection rods 1 based on the radio signals broadcast by the two detection rods 1, and to locate the distances from the two detection rods 1 to the fault point respectively in combination with the first time and the second time fed back by the two detection rods 1; the main board 21 of the handheld measuring instrument 2 is used to synchronously generate measurement instructions for the two detection rods 1 based on user instructions and forward them by the second wireless module 23; and, from the radio signals broadcast by each detection rod 1, extract the ID number and timestamp of each detection rod and send them to the positioning calculation module 24.

[0022] It can be seen that the probe rod 1 is mainly used for information collection. The demodulator 11 provided therein is the control center of the probe rod 1 to cooperate with the first wireless module 13 to wirelessly transmit the collected information data to the handheld measuring instrument 2, and the first UWB module 12 provided therein is used to measure the relative distance between the probe rods 1 in a two-dimensional plane and assist in relative position navigation. The LORA module 14 provided therein is used for clock calibration to ensure that the sound information collected by the BSS microphones 16 of the two probe rods 1 is synchronized on the time axis. The handheld measuring instrument 2 is mainly used for data analysis and position navigation.

[0023] It should be noted that after the detection rod 1 senses the magnetic field of the power cable L, the BSS microphone 16 records the sound information of 500ms before and after the fault sound and uses it as the original data packet for fault location. Combined with the relative distance measurement between the detection rod 1 and the first UWB module 12, the positioning calculation module 24 carried by the handheld measuring instrument 2 can be used to analyze the location of the fault sound, thereby achieving the purpose of fault location.

[0024] During measurement, the magnetic field of the power cable L must occur before the fault sound signal. Due to the extremely small time difference, the magnetic field induction of the two detection rods 1 and the occurrence of the fault sound signal are considered to occur simultaneously. The time when the magnetic field occurs is recorded as At this moment, the detection rod 1 starts to collect and record the sound signal. It takes a certain amount of time for the fault sound signal to occur and propagate through the medium to the sound sensor. The time when the sound signal reaches the BSS microphone 16 of the two detection rods 1 is recorded as , .

[0025] at this time, and , The time difference is the time difference between the first time and the second time in the two detection rods 1, which are respectively recorded as , ; and The time difference is the time difference between the two probe rods 1 at the second time, recorded as .pass Divide by Can measure the propagation speed of the sound signal in the current medium , and use * or * The relative distance between the fault sound source and the two detection rods 1 can be calculated , , and can also perform two-dimensional positioning in the plane.

[0026] In the embodiment of the present invention, in order to facilitate carrying, Figure 3As shown, each detection rod 1 includes a handle portion T1, a straight rod T2 and a measuring portion T3; wherein the straight rod T2 is a hollow tube made of metal and plastic, with the handle portion T1 installed on the top and the measuring portion T3 installed on the bottom, and a battery rod 18 for providing direct current to all modules and components is arranged in the tube; the handle portion T1 is made of metal and plastic, and a first UWB module 12, a first wireless module 13, a LORA module 14 and an RSS acoustic sensor 17 are arranged inside the handle portion T1; the measuring portion T3 is a hollow cylinder made of metal and plastic, and the hollow cylinder is in a sealed structure, and a demodulator 11, a magnetic flux sensor 15 and a BSS microphone 16 are arranged inside the measuring portion T3. It should be noted that the RSS acoustic sensor 17 is to strengthen the collection of the sound information of 500ms before and after the fault sound.

[0027] Of course, each detection rod 1 also includes a data interface 19 and an indicator light 20 arranged outside the handle part T1, and a level meter 201 arranged outside the measuring part T3; wherein, the data interface 19 is connected to the demodulator 11, which includes a serial port, a USB interface and a type-c interface; the indicator light 20 is connected to the demodulator 11 to display the working status; the level meter 201 is used to measure whether it is placed above the power cable L and reaches a balanced state.

[0028] In one example, the overall height of the probe rod 1 is 80 cm, the diameter is 15 cm, the weight does not exceed 5 kg, and the exterior uses a color scheme of yellow and black that is more obvious and widely used in engineering. The handle portion T1 (such as a handle) has a built-in first UWB module 12, a LORA module 14, a first wireless module 13 (such as a WIFI wireless module) and an RSS sound sensor 17, an external data interface 19 (type-c, with a plug), a charging interface (with a plug), a power switch and an indicator light 20.

[0029] Among them, the first UWB module 12 uses the Mini 4th generation DWM1000 module of Shenzhen Yanchuang IoT Technology Co., Ltd., with a specification of 24mm*35mm. The antenna it carries uses an omnidirectional SMA male plug with a specification of 50mm*10mm, and the power consumption is about 0.5w; The MIC used in the RSS sound sensor 17 is a silicon chip microphone, model SPH1878.

[0030] The rod body of the straight rod T2 has a built-in battery rod 18 to provide a DC12V power supply for the device. The battery rod 18 has a diameter of 27mm and a height of 200-300mm, and leaves a 5mm line spacing with the periphery of the straight rod T2.

[0031] Below the straight rod T2 is the measuring part T3, whose inner cavity is formed as an acoustic cavity, with a demodulator 11 installed at the top, a magnetic flux sensor 15 in the middle, and a BSS acoustic sensor 16 installed at the bottom.

[0032] Among them, the demodulator 11 is a self-developed device, which is used as the core controller of the detection rod. The chip model used is STM32H743IIT6. Its peripherals are equipped with a WiFi data transmission module, a high-precision constant calibration lora module, and a 1G plug-in TF storage card through SDIO.

[0033] The MIC used in the BSS sound sensor 16 is also a silicon chip microphone, model SPH1878.

[0034] In the embodiment of the present invention, in order to facilitate portability, the handheld measuring instrument 2 includes a housing, and the main board 21, the second UWB module 22, the second wireless module 23 and the positioning calculation module 24 are all integrated in the housing. Of course, the handheld measuring instrument 2 also includes a liquid crystal touch screen 25 connected to the main board 21; wherein the liquid crystal touch screen 25 is used for inputting and displaying user instructions, and displaying the calculation results of the positioning calculation module 24; wherein the calculation results include the distances from the two detection rods to the fault point, the spacing between the two detection rods, the propagation speed of the acoustic signal in the power cable, the time difference formed between the second time of the two detection rods, and the time difference formed between the first time and the second time of each of the detection rods, etc.

[0035] In one example, the handheld measuring instrument 2 has a size of 141*109*55mm, and its appearance is also yellow and black. Its main built-in components include an RK3588 motherboard 21 (Linux system), a 5-inch touch screen (i.e., an LCD touch screen 25), a second UWB module 22 and a battery pack, and a second wireless module 23 (such as a WIFI transparent transmission module), and its overall power consumption is about 10w.

[0036] Among them, the model of motherboard 21 is RCC-RK3588S-PC-V1.1, with specifications of 90mm * 60mm, DC12v power supply, (DC5.5×2.1mm, supports 9V~24V wide voltage input). Standby power consumption: about 0.42w (12V / 35mA), typical power consumption: about 2.25w (12V / 190mA), maximum power consumption: about 12w (12V / 1000mA).

[0037] Among them, the second UWB module 22 is the same as the first UWB module 12, both use the Mini 4th generation DWM1000 module of Shenzhen Yanchuang IoT Technology Co., Ltd., with a specification of 24mm*35mm. The antenna it carries uses an omnidirectional SMA male connector with a specification of 50mm*10mm and a power consumption of approximately 0.5w.

[0038] like Figure 4As shown, the application scenario of a power cable fault trench positioning system based on UWB, sound and magnetic flux proposed in an embodiment of the present invention is further described as follows: A. The surveyor randomly selects measurement points 1 and 2 above the power cable L, places two detection rods 1, and ensures that the measurement parts T3 (i.e., the sound cavity parts) under the two detection rods 1 are buried in the sand; B. After selecting the measuring point, turn on the power of the two probe rods 1, and the measuring personnel use the handheld measuring instrument 2 to cooperate with the two probe rods 1 to measure the distance between the measuring points 1 and 2. This process can be completed within 2 seconds; C. After the distance measurement between the measurement points 1 and 2 is completed, the two detection rods 1 will be in a standby state for collecting acoustic signals, and at the same time, the position of the handheld measuring instrument 2 will be located in real time; D. After the magnetic flux sensor 15 in the measuring part T3 under the two detection rods 1 senses the magnetic field of the power cable L, the BSS acoustic sensor 16 in the measuring part T3 under the two detection rods 1 is synchronously started to record the acoustic signal of the fault point. Since the clocks of the two detection rods 1 are synchronized through the LORA module 14, the information between the measurement points 1 and 2 can be regarded as synchronous recording; E. After the measurement is completed, the two probe rods 1 will transmit the audio information to the handheld measuring instrument 2. At this time, the handheld measuring instrument 2 has obtained the distance between the fault point and the measuring point and the audio information, and then based on the sound estimation method, the fault point can be quickly and accurately located; F. After the handheld measuring instrument 2 completes the data analysis and calculation using the fault location algorithm in the location calculation module 24, the fault point position is marked on the LCD touch screen 25. Finally, the measuring personnel can navigate to the fault point by holding the handheld measuring instrument 2.

[0039] In summary, the entire system equipment is relatively light and easy to carry, and can be carried with you regardless of urban or outdoor conditions. The entire system is relatively simple to use, and any operator can use it after a short training. All operations can be controlled by the handheld measuring instrument 2 to avoid repeated operation of different equipment by the staff. The entire system has a high positioning accuracy for the fault location, a long battery life, and can work continuously for 8 hours. The positioning accuracy within a radius of 40m reaches ±10cm. The entire system has a precise location navigation function. The second UWB positioning module 22 can be used to perform real-time positioning of the handheld measuring instrument 2 at the centimeter level. After clarifying the fault point information, the staff can move the handheld measuring instrument to the fault point. The entire system is easy to debug and maintain, and is equipped with a debugging and charging port. The outer shell is connected with bolts, and the detection rod can be replaced and charged and debugged according to the situation in the later stage. All components of the entire system adopt an integrated sealing design, which can effectively cope with various usage environments and has high waterproof and dustproof properties.

[0040] like Figure 5 As shown, a method for locating a power cable fault trench based on UWB, sound and magnetic flux is provided in an embodiment of the present invention. The method is implemented on a power cable fault trench locating system based on UWB, sound and magnetic flux in an embodiment of the present invention. The method comprises the following steps: Step S1, when two detection rods are randomly placed above a designated power cable, they periodically send time synchronization signals between them and periodically broadcast radio signals carrying their own ID numbers and timestamps to a handheld measuring instrument, and after confirming the time synchronization between the two, if a measurement instruction issued by the handheld measuring instrument is received, the first time of each initially measuring the magnetic field signal generated by the power cable is fed back to the handheld measuring instrument, and the second time of each initially measuring the acoustic signal sent by the fault point is fed back to the handheld measuring instrument; Step S2, the handheld measuring instrument receives the radio signals broadcast by the two detection rods, and based on the radio signals broadcast by the two detection rods, obtains the distance between the two detection rods, and further locates the distances from the two detection rods to the fault point in combination with the first time and the second time fed back by the two detection rods; wherein the distance from each detection rod to the fault point is obtained by first dividing the obtained distance between the two detection rods by the absolute value of the time difference formed between the second times of the two detection rods to obtain the propagation speed of the acoustic signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference formed by the first time and the second time.

[0041] Wherein, the method further comprises: According to the located distances from the two detection rods to the fault point, the first UWB modules preset on the two detection rods are used to locate and navigate to the fault point in real time.

[0042] Implementing the embodiments of the present invention has the following beneficial effects: The present invention obtains the distance between the two detection rods through a handheld measuring instrument according to the radio signals broadcast by the two detection rods and carrying their own ID numbers and timestamps, and further combines the first time when the two detection rods initially measure the magnetic field signal generated by the power cable and the second time when the sound signal sent by the fault point is initially measured, so as to quickly locate the distances from the two detection rods to the fault point respectively, thereby having the advantages of good stability, high positioning accuracy and fast positioning speed, etc., which can not only achieve the purpose of reducing manpower investigation and trench excavation, but also has social practical significance and engineering practical value.

[0043] It is worth noting that in the above-mentioned device embodiment, the various device units included are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be realized; in addition, the specific names of the various functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0044] A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, CD-ROM, etc.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A power cable fault trench positioning system based on UWB, sound and magnetic flux, characterized in that: It includes a handheld measuring instrument and two probe rods connected thereto respectively; wherein: Each of the detection rods is placed above a designated power cable, and is used to periodically broadcast a radio signal carrying its own ID number and timestamp to the handheld measuring instrument; and periodically send a time synchronization signal to another detection rod, and after confirming that time synchronization with the other detection rod is achieved, if a measurement instruction issued by the handheld measuring instrument is received, the first time of the magnetic field signal generated by the power cable initially measured is fed back to the handheld measuring instrument, and the second time of the acoustic signal sent by the fault point initially measured is fed back to the handheld measuring instrument; The handheld measuring instrument is used to obtain the distance between the two detection rods based on the radio signals broadcast by the two detection rods, and locate the distances from the two detection rods to the fault point in combination with the first time and the second time fed back by the two detection rods; wherein the distance from each detection rod to the fault point is obtained by first dividing the obtained distance between the two detection rods by the absolute value of the time difference formed between the second times of the two detection rods to obtain the propagation speed of the acoustic signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference formed between the first time and the second time.

2. The power cable fault trench positioning system based on UWB, sound and magnetic flux as claimed in claim 1, characterized in that: Each of the detection rods includes a demodulator and a first UWB module connected thereto, a first wireless module, a LORA module, a magnetic flux sensor and a BSS microphone; the handheld measuring instrument includes a mainboard and a second UWB module connected thereto, a second wireless module and a positioning calculation module; wherein, The first UWB module of each of the detection rods establishes communication with the second UWB module of the handheld measuring instrument, and is used to periodically broadcast a radio signal carrying its own ID number and timestamp to the second UWB module of the handheld measuring instrument; The first wireless module of each of the detection rods establishes communication with the second wireless module of the handheld measuring instrument, and is used for data transmission and interaction with the handheld measuring instrument; The LORA module of each detection rod establishes communication with the LORA module of another detection rod, and is used to periodically send a time synchronization signal to the LORA module of another detection rod based on the synchronization period preset by the demodulator to achieve time synchronization; The magnetic flux sensor of each of the detection rods is used to start measurement synchronously with the BSS microphone carried by itself based on the measurement instruction of the handheld measuring instrument demodulated by the demodulator, and periodically sense the magnetic field signal generated by the power cable in combination with the first acquisition cycle preset by the demodulator, and further feed back the first time of the initial sensing of the magnetic field signal generated by the power cable to the handheld measuring instrument; The BSS microphone of each of the detection rods is used to start measurement synchronously with the magnetic flux sensor carried by itself based on the measurement instruction of the handheld measuring instrument demodulated by the demodulator, and periodically measure the acoustic signal sent by the fault point in combination with the second acquisition cycle preset by the demodulator, and further feed back the second time from the initial measurement to the acoustic signal sent by the fault point to the handheld measuring instrument; The second UWB module of the handheld measuring instrument is used to periodically receive the radio signal broadcasted by each of the detection rods and carrying its own ID number and time stamp; The second wireless module of the handheld measuring instrument is used to receive data transmitted by each of the detection rods and to perform data exchange with each of the detection rods; The positioning calculation module of the handheld measuring instrument is used to obtain the distance between the two detection rods based on the radio signals broadcast by the two detection rods, and locate the distances from the two detection rods to the fault point respectively in combination with the first time and the second time fed back by the two detection rods; The mainboard of the handheld measuring instrument is used to synchronously generate measurement instructions for the two detection rods based on user instructions and forward them by the second wireless module; and to extract the ID number and timestamp of each detection rod from the radio signal broadcast by each detection rod and send them to the positioning calculation module.

3. The power cable fault trench positioning system based on UWB, sound and magnetic flux as claimed in claim 2, characterized in that: Each of the detection rods comprises a handle portion, a straight rod and a measuring portion; wherein, The straight rod is in the shape of a hollow tube, with the handle installed on the top and the measuring part installed on the bottom, and a battery rod for providing direct current to all modules and components is arranged inside the tube; The first UWB module, the first wireless module, the LORA module and the RSS acoustic sensor are arranged inside the handle; The measuring part is a hollow cylinder in a sealed structure, and the demodulator, the magnetic flux sensor and the BSS microphone are arranged inside the measuring part.

4. The power cable fault trench positioning system based on UWB, sound and magnetic flux as claimed in claim 3, characterized in that: Each of the detection rods also includes a data interface arranged outside the handle; wherein the data interface is connected to the demodulator, and includes a serial port, a USB interface and a type-c interface.

5. The power cable fault trench positioning system based on UWB, sound and magnetic flux as described in claim 4, characterized in that: Each of the detection rods also includes an indicator light arranged outside the handle; wherein the indicator light is connected to the demodulator to display the working status.

6. The power cable fault trench positioning system based on UWB, sound and magnetic flux as claimed in claim 5, characterized in that: Each of the detection rods further includes a level meter arranged outside the measuring part; wherein the level meter is used to measure whether a balance state is achieved when it is placed above the power cable.

7. The power cable fault trench positioning system based on UWB, sound and magnetic flux as claimed in claim 6, characterized in that: The handle part, the straight rod and the measuring part of each detection rod are made of metal and plastic.

8. The power cable fault trench positioning system based on UWB, sound and magnetic flux as claimed in claim 7, characterized in that: The handheld measuring instrument also includes a liquid crystal touch screen connected to the main board; wherein the liquid crystal touch screen is used for inputting and displaying user commands, and displaying the calculation results of the positioning calculation module; wherein the calculation results include the distances from the two detection rods to the fault point respectively, the spacing between the two detection rods, the propagation speed of the acoustic signal in the power cable, the time difference formed between the second times of the two detection rods, and the time difference formed between the first time and the second time of each detection rod.

9. A method for locating power cable faults in trenches based on UWB, sound and magnetic flux, characterized in that: The method is implemented on the power cable fault trench positioning system based on UWB, sound and magnetic flux as described in claim 8, and the method comprises the following steps: When the two detection rods are randomly placed above the designated power cable, they periodically send time synchronization signals between them and periodically broadcast radio signals carrying their own ID numbers and timestamps to the handheld measuring instrument. After confirming the time synchronization between the two, if a measurement instruction issued by the handheld measuring instrument is received, the first time of each initially measuring the magnetic field signal generated by the power cable is fed back to the handheld measuring instrument, and the second time of each initially measuring the acoustic signal sent by the fault point is fed back to the handheld measuring instrument. The handheld measuring instrument receives the radio signals broadcast by the two detection rods, and based on the radio signals broadcast by the two detection rods, obtains the distance between the two detection rods, and further locates the distances from the two detection rods to the fault point in combination with the first time and the second time fed back by the two detection rods; wherein the distance from each detection rod to the fault point is obtained by first dividing the obtained distance between the two detection rods by the absolute value of the time difference formed between the second times of the two detection rods to obtain the propagation speed of the acoustic signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference formed by the first time and the second time.

10. The method for locating a power cable fault in a trench based on UWB, sound and magnetic flux as claimed in claim 9, characterized in that: The method further comprises: According to the located distances from the two detection rods to the fault point, the first UWB modules preset on the two detection rods are used to locate and navigate to the fault point in real time.

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