Power cable fault in-trench locating system and method based on uwb, sound and magnetic flux

Abstract

The application discloses a kind of power cable fault ditch positioning system based on UWB, sound and magnetic flux, including hand-held measuring instrument and two detection rods;Each detection rod is placed above power cable, and periodically broadcasts wireless signal carrying its ID number and time stamp to hand-held measuring instrument;And, periodically send time synchronization signal to another detection rod and confirm time synchronization, if receiving the measurement instruction issued by hand-held measuring instrument, the first time of initial measurement power cable magnetic field signal and the second time of initial measurement fault point sound signal are fed back to hand-held measuring instrument;Hand-held measuring instrument obtains the interval between two detection rods based on the wireless signal of two detection rods, and locates the distance of two detection rods to fault point respectively in combination with the first and second time fed back by two detection rods. By implementing the present application, it has the advantages of good stability, high positioning accuracy and fast positioning speed, and can reduce manpower investigation and trenching.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, in particular to a power cable fault in-groove positioning system and method based on UWB, sound and magnetic flux. BACKGROUND

[0002] Power cables are an important part of power systems and an important guarantee for the development of modern national economy and people's life. With the expansion of urbanization and the increasing demand for industrial electricity, the scale of power cable laying is becoming more and more complex. In the vast power transmission network, a considerable part of the power cable is buried or in a trench, which is difficult to avoid failure during long-term use. Even if regular safety inspections are conducted to reduce the probability of cable failure as much as possible, the troubleshooting and repair work of the fault location of the cable failure will still bring considerable manpower and time cost to the power supply and distribution units, and also bring great inconvenience and economic loss to the surrounding factories and residents.

[0003] At present, the existing cable fault troubleshooting method is still mainly based on the original manual trenching method. Even with the help of more advanced sound seeking devices, it is still difficult to quickly and accurately find the fault point position of the faulty cable, especially for buried power cables in complex environments, which makes cable fault detection and positioning relatively difficult.

[0004] Therefore, there is an urgent need for a power cable fault positioning method with good stability, high positioning accuracy and fast positioning speed, which not only achieves the purpose of reducing manpower investigation and trenching, but also has social practical significance and engineering practical value. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a power cable fault in-groove positioning system and method based on UWB, sound and magnetic flux, which has the advantages of good stability, high positioning accuracy and fast positioning speed, and not only achieves the purpose of reducing manpower investigation and trenching, but also has social practical significance and engineering practical value.

[0006] In order to solve the above technical problems, the present application provides a positioning system of a power cable fault in-groove positioning system based on UWB, sound and magnetic flux, which comprises a handheld measuring instrument and two detection rods connected thereto respectively; wherein,

[0007] Each of the probe rods is arranged above a designated power cable, for periodically broadcasting a radio signal carrying its own ID number and time stamp to the handheld measuring instrument, and periodically sending a time synchronization signal to another probe rod, and after confirming that time synchronization with another probe rod is achieved, if a measurement instruction issued by the handheld measuring instrument is received, feeding back a first time of initially measuring a magnetic field signal generated by the power cable to the handheld measuring instrument, and feeding back a second time of initially measuring an acoustic signal sent by the fault point to the handheld measuring instrument;

[0008] The handheld measuring instrument is used to obtain the distance between two probe rods based on the radio signals broadcast by the two probe rods, and locate the distance of two probe rods to the fault point in combination with the first time and the second time fed back by the two probe rods; wherein the distance of each probe rod to the fault point is calculated by first dividing the obtained distance between the two probe rods by the absolute value of the time difference formed between the second time of the two probe 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.

[0009] Each of the probe rods comprises 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 comprises a mainboard and a second UWB module, a second wireless module and a positioning calculation module connected thereto; wherein,

[0010] The first UWB module of each of the probe 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 time stamp to the second UWB module of the handheld measuring instrument;

[0011] The first wireless module of each of the probe 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;

[0012] The LORA module of each of the probe rods establishes communication with the LORA module of another probe rod, and is used to periodically send a time synchronization signal to the LORA module of another probe rod based on the synchronization period preset by the demodulator, to achieve time synchronization;

[0013] The magnetic flux sensor of each detection rod is used for starting measurement synchronously with the BSS microphone carried by itself based on the measurement instruction of the handheld measuring instrument demodulated by the demodulator, periodically sensing the magnetic field signal generated by the power cable in combination with the first acquisition cycle preset by the demodulator, and further feeding back the first time of initially sensing the magnetic field signal generated by the power cable to the handheld measuring instrument.

[0014] The BSS microphone of each detection rod is used for starting measurement synchronously with the magnetic flux sensor carried by itself based on the measurement instruction of the handheld measuring instrument demodulated by the demodulator, periodically measuring the sound signal sent by the fault point in combination with the second acquisition cycle preset by the demodulator, and further feeding back the second time of initially measuring the sound signal sent by the fault point to the handheld measuring instrument.

[0015] The second UWB module of the handheld measuring instrument is used for periodically receiving the radio signal broadcast by each detection rod and carrying the ID number and the time stamp of itself.

[0016] The second wireless module of the handheld measuring instrument is used for receiving the data transmitted by each detection rod and performing data interaction with each detection rod.

[0017] The positioning calculation module of the handheld measuring instrument is used for obtaining the distance between two detection rods based on the radio signals broadcast by the two detection rods, and positioning the distances of 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.

[0018] The mainboard of the handheld measuring instrument is used for synchronously generating measurement instructions for two detection rods based on a user instruction and forwarding the measurement instructions by the second wireless module, and extracting the ID number and the time stamp of each detection rod from the radio signal broadcast by each detection rod and sending the ID number and the time stamp into the positioning calculation module.

[0019] Each detection rod comprises a handle part, a straight rod and a measurement part.

[0020] The straight rod is in a hollow tubular shape, the top of the straight rod is provided with the handle part, the bottom of the straight rod is provided with the measurement part, and a battery rod for providing direct current to all modules and components is arranged in the tube.

[0021] The handle part is internally provided with the first UWB module, the first wireless module, the LORA module and the RSS sound sensor.

[0022] The measurement part is a hollow column in a sealed structure, and the inside of the measurement part is provided with the demodulator, the magnetic flux sensor and the BSS microphone.

[0023] Each of the detection rods further comprises a data interface arranged outside the handle part; the data interface is connected with the demodulator and comprises a serial port, a USB interface and a type-c interface.

[0024] Each of the detection rods further comprises an indicator lamp arranged outside the handle part; the indicator lamp is connected with the demodulator and is used for displaying the working state.

[0025] Each of the detection rods further comprises a level arranged outside the measuring part; the level is used for measuring whether it is balanced when placed above the power cable.

[0026] The handle part, the straight rod and the measuring part of each of the detection rods are made of metal and plastic.

[0027] The handheld measuring instrument further comprises a liquid crystal touch screen connected with the mainboard; the liquid crystal touch screen is used for inputting and displaying the user instructions and displaying the calculation results of the positioning calculation module; the calculation results include the distances of the two detection rods to the fault point, the interval between the two detection rods, the propagation speed of the sound signal in the power cable, the time difference between the second time of the two detection rods and the time difference between the first time and the second time of each detection rod.

[0028] The embodiment of the application further provides a power cable fault trench in-position method based on UWB, sound and magnetic flux, which is realized on the aforementioned power cable fault trench in-position system based on UWB, sound and magnetic flux, and comprises the following steps:

[0029] When the two detection rods are randomly placed above the specified power cable, the time synchronization signals are periodically transmitted between the two detection rods, and the handheld measuring instrument is periodically broadcasted with radio signals carrying the ID number and the time stamp; after confirming the time synchronization between the two detection rods, if the measurement instruction issued by the handheld measuring instrument is received, the first time of initially measuring the magnetic field signal generated by the power cable is fed back to the handheld measuring instrument, and the second time of initially measuring the sound signal transmitted by the fault point is fed back to the handheld measuring instrument.

[0030] The handheld measuring instrument receives the radio signals broadcasted by the two detection rods, and obtains the distance between the two detection rods based on the radio signals broadcasted by the two detection rods, and further locates the distances from the two detection rods to the fault point respectively by combining 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 dividing the obtained distance between the two detection rods by the absolute value of the time difference between the second times of the two detection rods to obtain the propagation speed of the sound signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference between the first time and the second time.

[0031] The method further comprises:

[0032] According to the located distances from the two detection rods to the fault point respectively, the first UWB module pre-set on the two detection rods is used to locate and navigate to the fault point in real time.

[0033] The embodiment of the present application has the following advantages:

[0034] The handheld measuring instrument obtains the distance between the two detection rods according to the radio signals broadcasted by the two detection rods and carrying the ID numbers and time stamps of the two detection rods, and further locates the distances from the two detection rods to the fault point respectively by combining the first time and the second time, which are the first time at which the two detection rods initially measure the magnetic field signal of the power cable and the second time at which the two detection rods initially measure the sound signal sent by the fault point, so that the distances from the two detection rods to the fault point are quickly located, and the advantages of good stability, high positioning accuracy and fast positioning speed are achieved, which not only achieves the purpose of reducing manpower investigation and trenching, but also has social practical significance and engineering practical value. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0036] Fig. 1 is a structural schematic diagram of a power cable fault trench positioning system based on UWB, sound and magnetic flux provided by an embodiment of the present application;

[0037] Fig. 2 is a whole function block diagram of a power cable fault trench positioning system based on UWB, sound and magnetic flux provided by an embodiment of the present application;

[0038] Fig. 3 is a plan view of a single detection rod in a power cable fault trench positioning system based on UWB, sound and magnetic flux according to an embodiment of the present application;

[0039] Fig. 4 is a schematic diagram of an application scenario of a power cable fault trench positioning system based on UWB, sound and magnetic flux according to an embodiment of the present application;

[0040] Fig. 5 is a flowchart of a power cable fault trench positioning method based on UWB, sound and magnetic flux according to an embodiment of the present application. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be given below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0042] As shown in Fig. 1, according to an embodiment of the present application, a power cable fault trench positioning system based on UWB, sound and magnetic flux is provided, which comprises a handheld measuring instrument 2 and two detection rods 1 connected to the handheld measuring instrument 2 respectively; wherein,

[0043] Each detection rod 1 is placed above a designated power cable L, and is configured to periodically (e.g., every 2 seconds) broadcast a wireless signal carrying its own ID number and a time stamp to the handheld measuring instrument 2, and periodically (e.g., every 1 minute) send a time synchronization signal to the other detection rod, and after confirming that time synchronization with the other detection rod is achieved, if a measurement instruction is received from the handheld measuring instrument 2, the first time at which the magnetic field signal generated by the power cable L is initially measured is fed back to the handheld measuring instrument 2, and the second time at which the sound signal sent by the fault point is initially measured is fed back to the handheld measuring instrument 2.

[0044] The handheld measuring instrument 2 is configured to obtain the distance between the two detection rods 1 based on the wireless signals broadcast by the two detection rods 1, and locate the distances from the two detection rods 1 to the fault point based on 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 calculated by first dividing the distance between the two detection rods 1 by the absolute value of the time difference between the second times of the two detection rods 1 to obtain the propagation speed of the sound signal in the power cable L, and then multiplying the obtained propagation speed by the absolute value of the time difference between the first time and the second time.

[0045] At this time, as shown in FIG. 2, each detection rod 1 includes a demodulator 11 and a first UWB module 12, a first wireless module 13, a LORA module 14, a magnetic flux sensor 15 and a BSS microphone 16 connected thereto; the handheld measuring instrument 2 includes a mainboard 21 and a second UWB module 22, a second wireless module 23 and a positioning calculation module 24 connected thereto; wherein,

[0046] The first UWB module 12 of each detection rod 1 establishes communication with the second UWB module of the handheld measuring instrument 2, and is used for periodically (e.g., once every 2S) broadcasting a radio signal carrying an ID number and a time stamp of itself 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 for data transmission and interaction 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 for periodically (e.g., once every 1min) sending a time synchronization signal to the LORA module 14 of another detection rod 1 based on a synchronization period preset by the demodulator 11, to realize time synchronization; the magnetic flux sensor 15 of each detection rod 1 is used for synchronously starting measurement with the BSS microphone 16 carried by itself based on a measurement instruction of the handheld measuring instrument 2 demodulated by the demodulator 11, and periodically (e.g., once every 2S) senses a magnetic field signal generated by the power cable L in combination with a first acquisition period preset by the demodulator 11, and further feeds back a first time of initially sensing the magnetic field signal generated by the power cable L to the handheld measuring instrument 2 through the first wireless module 13; the BSS microphone 16 of each detection rod 1 is used for synchronously starting measurement with the magnetic flux sensor 15 carried by itself based on a measurement instruction of the handheld measuring instrument 2 demodulated by the demodulator 11, and periodically (e.g., once every 2S) measures a sound signal sent by a fault point in combination with a second acquisition period preset by the demodulator 11, and further feeds back a second time of initially measuring the sound signal sent by the fault point to the handheld measuring instrument through the first wireless module 13;

[0047] The second UWB module 22 of the handheld measuring instrument 2 is used for periodically receiving the radio signals broadcast by each probe rod 1, which carry the ID number and time stamp of the probe rod 1; the second wireless module 23 of the handheld measuring instrument 2 is used for receiving the data transmitted by each probe rod 1 and interacting with each probe rod 1; the positioning calculation module 24 of the handheld measuring instrument 2 is used for obtaining the distance between the two probe rods 1 based on the radio signals broadcast by the two probe rods 1, and positioning the distances from the two probe rods 1 to the fault point in combination with the first time and the second time fed back by the two probe rods 1; the mainboard 21 of the handheld measuring instrument 2 is used for generating measurement instructions for the two probe rods 1 synchronously based on a user instruction and forwarding the measurement instructions by the second wireless module 23; and the ID number and time stamp of each probe rod are extracted from the radio signals broadcast by each probe rod 1 and sent to the positioning calculation module 24.

[0048] It can be seen that the probe rod 1 is mainly used for information collection, the demodulator 11 arranged in the probe rod 1 is a control center of the probe rod 1 and is used for wirelessly transmitting the collected information data to the handheld measuring instrument 2 in cooperation with the first wireless module 13, the first UWB module 12 arranged in the probe rod 1 is used for measuring the relative distance between the two probe rods 1 in a two-dimensional plane and assisting in relative position navigation, and the LORA module 14 arranged in the probe rod 1 is used for clock calibration to ensure that the sound information collected by the BSS microphones 16 of the two probe rods 1 is in a synchronous state on a time axis. The handheld measuring instrument 2 is mainly used for data analysis and position navigation.

[0049] It should be noted that after the probe rod 1 senses the magnetic field of the power cable L, the BSS microphone 16 records the sound information of 500 ms before and after the fault sound and takes the sound information as the original data packet for fault positioning, and in combination with the relative distance measurement between the two probe rods 1 by the first UWB module 12, the position of the fault sound can be analyzed by the positioning calculation module 24 carried by the handheld measuring instrument 2, so as to achieve the purpose of fault positioning.

[0050] The magnetic field of the power cable L is certainly prior to the occurrence of the fault sound signal during measurement, and since the time difference is extremely small, the magnetic field induction and the occurrence of the fault sound signal of the two probe rods 1 are considered to occur at the same time. The moment when the magnetic field occurs is recorded as At this moment, the probe rod 1 starts to collect and record the sound signal. The moment when the fault sound signal occurs and propagates to the sound sensor through the medium is recorded as , .

[0051] At this moment, and , The time difference is the time difference between the first time and the second time of the two probe rods 1, which are recorded as , ; With The time difference is the time difference of the second time between the two detection rods 1, denoted as . By Divided by The propagation speed of the sound signal in the current medium , and using * Or * The relative distance between the fault sound source and the two detection rods 1 , , can be calculated, and the two-dimensional positioning in the plane can be performed.

[0052] In the embodiment of the application, in order to facilitate carrying, as shown in FIG. 3, each detection rod 1 comprises a handle part T1, a straight rod T2 and a measuring part T3; wherein the straight rod T2 is a hollow pipe made of metal and plastic, the top of which is provided with the handle part T1, and the bottom of which is provided with the measuring part T3, and a battery rod 18 is arranged in the pipe for providing direct current to all modules and components; the handle part T1 is made of metal and plastic, and the inside of which is provided with a first UWB module 12, a first wireless module 13, a LORA module 14 and an RSS sound sensor 17; the measuring part T3 is a hollow column made of metal and plastic, and the hollow column is in a sealed structure, and the inside of which is provided with a demodulator 11, a magnetic flux sensor 15 and a BSS microphone 16. It should be noted that the RSS sound sensor 17 is used to strengthen the collection of sound information of 500ms before and after the fault sound.

[0053] Of course, each detection rod 1 also comprises a data interface 19 and an indicator light 20 arranged outside the handle part T1, and a level 201 arranged outside the measuring part T3; wherein the data interface 19 is connected with the demodulator 11, and comprises a serial port, a USB interface and a type-c interface; the indicator light 20 is connected with the demodulator 11 and is used to display the working state; the level 201 is used to measure whether it is balanced when placed above the power cable L.

[0054] In one example, the overall height of the detection rod 1 is 80cm, the diameter is 15cm, and the weight does not exceed 5kg, and the appearance uses a color matching scheme that is relatively obvious in yellow and black and is widely used in engineering applications. The handle part T1 (such as a handle) is internally provided with a 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, and externally provided with a data interface 19 (type-c with a plug), a charging interface (with a plug), a power switch and an indicator light 20.

[0055] 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, and the antenna carried thereon uses an omnidirectional SMA male head, with a specification of 50mm*10mm and a power consumption of about 0.5w.

[0056] The MIC used by the RSS acoustic sensor 17 is a silicon chip microphone, with a model number of SPH1878.

[0057] The battery rod 18 built in the rod body of the straight rod T2 provides a DC 12V power supply for the device, has a diameter of 27mm and a height of 200-300mm, and is spaced from the periphery of the straight rod T2 by 5mm for wire passing.

[0058] The lower part of the straight rod T2 is the measuring part T3, the inner cavity of which is formed as an acoustic cavity, the uppermost part of which is provided with the demodulator 11, the middle part of which is provided with the magnetic flux sensor 15, and the bottom part of which is provided with a BSS acoustic sensor 16.

[0059] The demodulator 11 is a self-developed device, which is used as a detection rod to carry all core controllers, uses a chip with a model number of STM32H743IIT6, and is provided with a WIFI data transmission module, a high-precision always-calibrated LORA module and a 1G plug-in TF storage card through an SDIO.

[0060] The MIC used by the BSS acoustic sensor 16 is also a silicon chip microphone, with a model number of SPH1878.

[0061] In the embodiment of the application, in order to facilitate carrying, the handheld measuring instrument 2 comprises a shell, and the mainboard 21, the second UWB module 22, the second wireless module 23 and the positioning calculation module 24 are all integrated in the shell. Of course, the handheld measuring instrument 2 further comprises a liquid crystal touch screen 25 connected with the mainboard 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 of the two detection rods to the fault point, the distance between the two detection rods, the propagation speed of the acoustic signal in the power cable, the time difference between the second time of the two detection rods and the time difference between the first time and the second time of each detection rod.

[0062] In one example, the specification of the handheld measuring instrument 2 is 141*109*55mm, and the appearance is also matched with yellow and black. The built-in main components include an RK3588 mainboard 21 (Linux system), a 5-inch touch screen (i.e. the liquid crystal touch screen 25), a second UWB module 22 and a battery block, a second wireless module 23 (such as a WIFI transparent transmission module), and the overall power consumption is about 10w.

[0063] Motherboard 21 is model RCC-RK3588S-PC-V1.1, with dimensions of 90mm x 60mm, a DC12V power supply (DC5.5 x 2.1mm, supporting a wide voltage input range of 9V to 24V). Standby power consumption is approximately 0.42W (12V / 35mA), typical power consumption is approximately 2.25W (12V / 190mA), and maximum power consumption is approximately 12W (12V / 1000mA).

[0064] Among them, the second UWB module 22 is the same as the first UWB module 12, both using 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.

[0065] As shown in FIG4 , an application scenario of a power cable fault trench location system based on UWB, sound, and magnetic flux proposed in an embodiment of the present invention is further described as follows:

[0066] A. The surveyor randomly selects measurement points 1 and 2 above the power cable L, places two probe rods 1, and ensures that the measurement parts T3 (i.e., the acoustic cavity) below the two probe rods 1 are buried in the sand;

[0067] B. After selecting the measuring point, turn on the power of the two probe rods 1. The surveyor uses 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.

[0068] C. After the distance measurement between the measurement points 1 and 2 is completed, the two probe 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;

[0069] D. After the magnetic flux sensor 15 in the measuring section T3 below the two probe rods 1 senses the magnetic field of the power cable L, it simultaneously activates the BSS acoustic sensor 16 in the measuring section T3 below the two probe rods 1 to record the acoustic signal at the fault point. Because the clocks of the two probe rods 1 are synchronized via the LORA module 14, the information between measurement points 1 and 2 can be considered to be recorded synchronously.

[0070] E. After the measurement is completed, the two probe rods 1 will transmit the audio information to the handheld measuring instrument 2. At this point, the handheld measuring instrument 2 has obtained the distance between the fault point and the measurement point and the audio information, and then based on the sound estimation method, it can achieve rapid and high-precision positioning of the fault point;

[0071] F, the handheld measuring instrument 2 marks the fault point position on the liquid crystal touch screen 25 after the data analysis and calculation is completed by the fault location algorithm in the positioning calculation module 24, and finally the measurement personnel can navigate to the fault point by holding the handheld measuring instrument 2.

[0072] As can be seen, the entire system device is relatively light and easy to carry, and can be carried on the body in urban or outdoor working conditions. The entire system is relatively simple to use, and any operator can use it after a short training, and all operations can be controlled through the handheld measuring instrument 2, avoiding repeated operation of different devices by the operator. The entire system has high positioning accuracy for fault location, long endurance, and can work continuously for 8h, and the positioning accuracy within a radius of 40m is ±10cm. The entire system has accurate position navigation function, and the second UWB positioning module 22 can be used to perform real-time positioning of the handheld measuring instrument 2 to the centimeter level, and the operator can move to the fault point by holding the measuring instrument after the fault point information is determined. The entire system is convenient to debug and maintain, and is provided with a debugging and charging port, and the shell connection adopts a bolt, and the detection rod can be replaced and charged for debugging in the later period. The entire system is designed in an integrated and sealed manner, can effectively cope with various use environments, and has high waterproof and dustproof properties.

[0073] As shown in FIG. 5, in the embodiment of the application, a UWB, sound and magnetic flux-based power cable fault trench positioning method is provided, which is implemented on the UWB, sound and magnetic flux-based power cable fault trench positioning system in the embodiment of the application, and the method comprises the following steps:

[0074] Step S1, when the two detection rods are randomly placed above the specified power cable, the time synchronization signals are periodically sent between the two detection rods, and the handheld measuring instrument is periodically broadcasted with radio signals carrying the ID number and time stamp of itself, and after confirming the time synchronization between the two, if the measurement instruction issued by the handheld measuring instrument is received, the first time when each initially measures the magnetic field signal generated by the power cable is fed back to the handheld measuring instrument, and the second time when each initially measures the sound signal sent by the fault point is fed back to the handheld measuring instrument;

[0075] Step S2, the handheld measuring instrument receives the radio signals broadcasted by the two probe rods, and obtains the distance between the two probe rods based on the radio signals broadcasted by the two probe rods, and further locates the distances from the two probe rods to the fault point respectively by combining the first time and the second time fed back by the two probe rods; wherein the distance from each probe rod to the fault point is obtained by dividing the obtained distance between the two probe rods by the absolute value of the time difference between the second times of the two probe rods to obtain the propagation speed of the sound signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference between the first time and the second time.

[0076] The method further comprises:

[0077] According to the located distances from the two probe rods to the fault point respectively, the first UWB module pre-set on the two probe rods is used to locate and navigate to the fault point in real time.

[0078] The embodiment of the present application has the following beneficial effects:

[0079] The present application obtains the distance between the two probe rods by the handheld measuring instrument according to the radio signals broadcasted by the two probe rods carrying the ID numbers and time stamps of the two probe rods, and further locates the distances from the two probe rods to the fault point respectively by combining the first time and the second time, which has the advantages of good stability, high positioning accuracy and fast positioning speed, and not only can achieve the purpose of reducing manpower investigation and trenching, but also has social practical significance and engineering practical value.

[0080] It is worth noting that in the above-mentioned device embodiment, each device unit is only divided according to functional logic, but is not limited to the above-mentioned division, as long as the corresponding function can be realized; in addition, the specific names of each functional unit are only for easy mutual differentiation, and do not limit the protection scope of the present application.

[0081] Those skilled in the art can understand that all or part of the steps of the above-mentioned embodiment methods can be completed by programs instructing related hardware, and the programs can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disc, etc.

[0082] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A power cable fault location system in a trench based on UWB, sound and magnetic flux, characterized in that, The handheld measuring instrument and two detection rods connected thereto respectively, wherein Each detection rod is arranged above a designated power cable, and is configured to periodically broadcast a radio signal carrying an ID number and a time stamp of the detection rod to the handheld measuring instrument, periodically send a time synchronization signal to another detection rod, and after confirming time synchronization with the other detection rod, if a measurement instruction is received from the handheld measuring instrument, feed back a first time of initially measuring a magnetic field signal generated by the power cable to the handheld measuring instrument, and feed back a second time of initially measuring an acoustic signal sent by the fault point to the handheld measuring instrument; The handheld measuring instrument is configured to obtain a distance between the two detection rods based on the radio signals broadcast by the two detection rods, and locate distances of the two detection rods to the fault point based on the first time and the second time fed back by the two detection rods, wherein the distance of each detection rod to the fault point is calculated by dividing the obtained distance between the two detection rods by an absolute value of a time difference between the first time and the second time, obtaining a propagation speed of the acoustic signal in the power cable, and multiplying the obtained propagation speed by an absolute value of a time difference between the first time and the second time.

2. The UWB, sound and magnetic flux based in-trench power cable fault location system of claim 1, wherein, Each detection rod comprises a demodulator and a first UWB module, a first wireless module, a LORA module, a magnetic flux sensor and a BSS microphone connected to the demodulator; the handheld measuring instrument comprises a mainboard and a second UWB module, a second wireless module and a positioning calculation module connected to the mainboard; wherein The first UWB module of each detection rod establishes communication with the second UWB module of the handheld measuring instrument, and is configured to periodically broadcast a radio signal carrying an ID number and a time stamp of the detection rod to the second UWB module of the handheld measuring instrument; The first wireless module of each detection rod establishes communication with the second wireless module of the handheld measuring instrument, and is configured to perform 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 configured to periodically send a time synchronization signal to the LORA module of the other detection rod based on a synchronization period preset by the demodulator, so as to achieve time synchronization; The magnetic flux sensor of each detection rod is configured to, based on a measurement instruction demodulated by the demodulator, open measurement synchronously with the BSS microphone carried by the detection rod, periodically sense a magnetic field signal generated by the power cable based on a first acquisition period preset by the demodulator, and further feed back a first time of initially sensing the magnetic field signal generated by the power cable to the handheld measuring instrument; The BSS microphone of each detection rod 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, periodically measure the acoustic signal sent by the fault point combined with the second acquisition cycle preset by the demodulator, and further feed back the second time of initially measuring 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 broadcast by each detection rod and carrying the ID number and time stamp of itself; The second wireless module of the handheld measuring instrument is used to receive the data transmitted by each detection rod and interact with each detection rod. The positioning calculation module of the handheld measuring instrument is used to obtain the distance between two detection rods based on the radio signals broadcast by the two detection rods, and locate the distance of two detection rods to the fault point combined 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 generate measurement instructions synchronously for two detection rods based on user instructions and forward them by the second wireless module, and extract the ID number and time stamp of each detection rod from the radio signal broadcast by each detection rod and send them into the positioning calculation module.

3. The UWB, sound and magnetic flux based in-pit power cable fault location system of claim 2, wherein, Each detection rod comprises a handle part, a straight rod and a measurement part. The straight rod is a hollow tube, the top of which is provided with the handle part, and the bottom of which is provided with the measurement part, and a battery rod is arranged in the tube to provide direct current for all modules and components. The handle part is internally provided with the first UWB module, the first wireless module, the LORA module and the RSS acoustic sensor. The measurement part is a hollow column in a sealed structure, and the inside of which is provided with the demodulator, the magnetic flux sensor and the BSS microphone.

4. The UWB, sound and magnetic flux based power cable fault in-trench locating system of claim 3, wherein, Each detection rod further comprises a data interface arranged outside the handle part, wherein the data interface is connected with the demodulator and comprises a serial port, a USB interface and a type-c interface.

5. The UWB, sound and magnetic flux based power cable fault in-trench locating system as claimed in claim 4, wherein, Each detection rod further comprises an indicator lamp arranged outside the handle part, wherein the indicator lamp is connected with the demodulator and is used to display the working state.

6. The UWB, sound and magnetic flux based power cable fault in-trench locating system as claimed in claim 5, wherein, Each detection rod further comprises a level meter arranged outside the measurement part, wherein the level meter is used to measure whether it reaches a balanced state when placed above the power cable.

7. The UWB, sound and magnetic flux based power cable fault in-trench locating system as defined in claim 6, characterized in that, The handle part, the straight rod and the measurement part of each detection rod are made of metal and plastic.

8. The UWB, sound and magnetic flux based power cable fault in-trench locating system as claimed in claim 7, wherein, The handheld measuring instrument further comprises a liquid crystal touch screen connected with the mainboard, wherein the liquid crystal touch screen is used for input and display of user instructions and display of the calculation results of the positioning calculation module, and the calculation results comprise the distance of two detection rods to the fault point, the distance between two detection rods, the propagation speed of the acoustic signal in the power cable, the time difference between the second time of two detection rods, and the time difference between the first time and the second time of each detection rod.

9. A method for in-trench locating of power cable faults based on UWB, sound and magnetic flux, characterized by, It is implemented on the UWB, sound and magnetic flux-based power cable fault trench positioning system as claimed in claim 8, and the method comprises the following steps: When two detection rods are randomly placed above the designated power cable, they periodically send time synchronization signals between each other and periodically broadcast radio signals carrying their own ID numbers and time stamps to the handheld measuring instrument, and after confirming the time synchronization between them, if the measurement instruction issued by the handheld measuring instrument is received, the first time of each initial measurement of the magnetic field signal generated by the power cable is fed back to the handheld measuring instrument, and the second time of each initial measurement of the sound 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, the distance between the two detection rods is obtained, and further combined with the first time and the second time fed back by the two detection rods, the distances of the two detection rods to the fault point are located respectively; wherein the distance of 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 between the second times of the two detection rods to obtain the propagation speed of the sound signal in the power cable, and then multiplying the obtained propagation speed by the absolute value of the time difference between the first time and the second time to calculate.

10. The UWB, sound and magnetic flux based in-pit power cable fault location method according to claim 9, wherein, The method further comprises: According to the distances of the two detection rods to the fault point located respectively, the first UWB module preset on the two detection rods is used to navigate to the fault point in real time.

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