A method, device and storage medium for cable defect location

Abstract

The present application discloses a method, device and storage medium for cable defect location. The method includes: inputting a detection signal from the head end of the cable to be measured, and collecting a reflection signal corresponding to the detection signal at the head end of the cable to be measured; processing the reflection signal based on the Hilbert transform to construct an amplitude function corresponding to the reflection signal; determining a first signal range and a second signal range in the reflection signal based on the amplitude function, and dividing the reflection signal into several segmented signals based on the first signal range and the second signal range; processing the several segmented signals through a Wigner distribution function to obtain corresponding several time-frequency distributions, and integrating the several time-frequency distributions to obtain a first time-frequency distribution function corresponding to the reflection signal; comparing the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect location of the cable to be measured. The present application improves the location accuracy of cable defects through the above method.

Description

Technical Field

[0001] This application relates to the technical field of cable fault location, and particularly to a cable defect location method, device, and storage medium. Background Art

[0002] Due to its good electrical strength and mechanical properties, the cable has become a crucial power transmission tool in the power system. However, under the influence of adverse factors such as manufacturing process errors, installation wear, and long-term operation, local damage defects will appear on the cable. If the defects cannot be located and repaired in time, they may eventually develop into permanent faults, affecting the quality of power transmission and even causing power outages.

[0003] Regular cable maintenance is one of the necessary measures to ensure the stability of the power system. The early manual line inspection method is time-consuming and laborious, so cable defect detection means based on electrical signals have been developed. However, the existing cable defect detection means based on electrical signals have problems such as inaccurate positioning and inability to locate minor defects. Therefore, how to improve the positioning accuracy of cable defects has become a technical problem to be solved urgently. Summary of the Invention

[0004] Embodiments of this application provide a cable defect location method, device, and storage medium to solve the following technical problem: how to improve the positioning accuracy of cable defects.

[0005] In a first aspect, embodiments of this application provide a cable defect location method, which is characterized in that the method includes: inputting a detection signal from the head end of the cable to be measured, and collecting a reflection signal corresponding to the detection signal at the head end of the cable to be measured; processing the reflection signal based on the Hilbert transform to construct an amplitude function corresponding to the reflection signal; wherein, the amplitude function is used to describe the contour of the reflection signal; based on the amplitude function, determine a first signal range and a second signal range in the reflection signal, and divide the reflection signal into several segmented signals based on the first signal range and the second signal range; wherein, the first signal range is used to describe the part of the reflection signal corresponding to the head end of the cable; the second signal range is used to describe the part of the reflection signal corresponding to the tail end of the cable; process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain a first time-frequency distribution function corresponding to the reflection signal; compare the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect location of the cable to be measured.

[0006] A cable defect location method provided by an embodiment of the present application processes a reflection signal through Hilbert transform to determine an amplitude function corresponding to the reflection signal. Thus, based on the amplitude function, signal components corresponding to the cable head end and the cable tail end in the reflection signal can be segmented to avoid the problem of cross-term interference that exists when directly using a multi-component reflection signal, thereby improving the accuracy of defect location of the cable to be measured. The defect location of the cable to be measured is determined by comparing the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function.

[0007] In an implementation manner of the present application, processing the reflection signal based on Hilbert transform to construct an amplitude function corresponding to the reflection signal specifically includes: performing Hilbert transform on the reflection signal to obtain an imaginary component corresponding to the reflection signal; where the imaginary component is used to describe a complex-type signal corresponding to the detection signal, and the signal formed by reflection of its imaginary part in the cable to be measured; processing the reflection signal and the imaginary component based on a preset amplitude function construction formula to obtain an amplitude function corresponding to the reflection signal.

[0008] In an implementation manner of the present application, based on the amplitude function, determining a first signal range and a second signal range in the reflection signal specifically includes: determining several maximum points in the amplitude function, and determining a first maximum point and a second maximum point among the several maximum points; respectively determining two points with the absolute value of the slope equal to a preset threshold in the neighborhoods of the first maximum point and the second maximum point; based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determining the first signal range, and based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the second maximum point, determining the second signal range.

[0009] In an implementation manner of the present application, based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determining the first signal range specifically includes: determining the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point as first signal range points, and determining the time parameters corresponding to the first signal range points; based on the two time parameters corresponding to the first signal range points, determining a first time range; based on the first time range, determining the first signal range in the reflection signal.

[0010] In an implementation manner of the present application, after determining the defect location of the cable to be measured, the method further includes: determining the defect degree of the defect based on a preset defect degree determination function;

[0011] Among them, the defect degree determination function is determined by the following formula:

[0012]

[0013] where A(t) is the defect degree determination function of the time variable t, and t′ is the time variable of integration; T s is half of the detection signal duration; ω is the instantaneous angular frequency of the signal; W r is the time-frequency distribution of the reflected signal; W s is the time-frequency distribution of the detection signal.

[0014] In an implementation manner of the present application, the amplitude function construction formula is determined by the following formula:

[0015]

[0016] where A m (t) is the amplitude function, r(t) is the reflected signal, and H[r(t)] is the imaginary component.

[0017] In an implementation manner of the present application, the second time-frequency distribution function corresponding to the detection signal is compared with the first time-frequency distribution function for correlation to determine the defect position of the cable to be measured, specifically including: based on the first time-frequency distribution function and the second time-frequency distribution function, determining the defect location curve of the cable to be measured through a preset cross-correlation function, and based on the defect location curve, determining the defect location point; where the defect location point is the extreme point on the defect location curve for describing the defect position; based on the time parameter corresponding to the defect location point in the defect location curve, determining the distance from the defect to the cable head end.

[0018] In an implementation manner of the present application, before determining the distance from the defect to the cable head end based on the time parameter corresponding to the defect location point in the defect location curve, the method further includes: determining the performance parameters of the cable to be measured; and calculating the transmission speed of the reflected signal in the cable based on the performance parameters of the cable to be measured.

[0019] In a second aspect, an embodiment of the present application further provides a cable defect location device, which is characterized in that the device includes: a processor; and a memory, on which an executable code is stored, and when the executable code is executed, the processor executes a method according to any one of claims 1-8.

[0020] In a third aspect, an embodiment of the present application further provides a non-volatile computer storage medium for cable defect location, storing computer-executable instructions, characterized in that the computer-executable instructions are set as follows: input a detection signal from the head end of the cable to be tested, and collect the reflection signal corresponding to the detection signal at the head end of the cable to be tested; process the reflection signal based on the Hilbert transform to construct an amplitude function corresponding to the reflection signal; wherein, the amplitude function is used to describe the profile of the reflection signal; based on the amplitude function, determine a first signal range and a second signal range in the reflection signal, and divide the reflection signal into several segmented signals based on the first signal range and the second signal range; wherein, the first signal range is used to describe the part of the reflection signal corresponding to the head end of the cable; the second signal range is used to describe the part of the reflection signal corresponding to the tail end of the cable; process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain a first time-frequency distribution function corresponding to the reflection signal; compare the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect location of the cable to be tested. Description of the Drawings

[0021] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation of the present application. In the drawings:

[0022] Figure 1 It is a flowchart of a method for cable defect location provided by an embodiment of the present application;

[0023] Figure 2 It is a schematic internal structure diagram of a cable defect location device provided by an embodiment of the present application. Detailed Embodiments

[0024] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0025] Due to its good electrical strength and mechanical properties, cables have become crucial power transmission tools in the power system. However, due to the influence of adverse factors such as manufacturing process errors, installation wear, and long-term operation, local damage defects may occur on the cables. If the defects cannot be located and repaired in time, they may eventually develop into permanent faults, affecting the quality of power transmission and even causing power outages.

[0026] Regularly maintaining and inspecting cables is one of the necessary measures to ensure the stability of the power system. The early manual line inspection method was time-consuming and laborious, so cable defect detection methods based on electrical signals have been developed. The reflection method is one of the main electrical detection methods, which can be mainly divided into the time-domain reflectometry (TDR), frequency-domain reflectometry (FDR), and time-frequency domain reflectometry (TFDR) according to the incident signal and the analysis domain: The TDR generally uses a pulse or step signal as the incident signal and analyzes based on the time-domain waveform; the FDR uses a swept-frequency signal as the incident signal, converts the data obtained from the frequency-domain measurement into a curve of cable distance, and then obtains the defect location; the TFDR uses a linear chirp signal with a Gaussian envelope as the incident signal, converts the time-domain acquired waveform to the time-frequency domain, and analyzes the defect information in the time-frequency domain.

[0027] The embodiments of the present application provide a cable defect location method, device, and storage medium to solve the following technical problem: how to improve the accuracy of cable defect location.

[0028] The technical solutions proposed in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0029] Figure 1 It is a flowchart of a cable defect location method provided by the embodiments of the present application. As Figure 1 shown, a cable defect location method provided by the embodiments of the present application specifically includes the following steps:

[0030] Step 101: Input the detection signal from the head end of the cable to be measured, and collect the reflection signal corresponding to the detection signal at the head end of the cable to be measured.

[0031] In an embodiment of the present application, a detection signal is provided to achieve the location of cable defects. It should be noted that the detection signal is determined by the following formula:

[0032]

[0033] where r(t) is the detection signal, t is the output time of the preset detection signal, α is the first constant, t0 is the time center of the signal, β is the second constant, and ω0 is the angular frequency center of the signal. It should be noted that the first constant is a parameter inversely related to the signal duration, and the second constant is a parameter affecting the signal frequency range.

[0034] In the embodiments of the present application, it is optional to take α as 2.21×10 16 , take t0 as 0 s, ω0 as 2π * 150 M, and β can be calculated based on the following formula:

[0035]

[0036] where B sThe bandwidth of the signal generator that generates the detection signal.

[0037] In one embodiment of the present application, after determining the detection signal, the detection signal is input from the head end of the cable under test. It can be understood that the head end of the cable under test is the detection end for detecting the cable under test; the detection signal generated by the signal generator is a time-domain signal and a real number signal.

[0038] In one embodiment of the present application, after inputting the detection signal from the head end of the cable under test, a reflected signal returned based on the detection signal is also collected at the head end of the cable under test. It can be understood that after the signal is input into the cable under test, the signal will be reflected, and the reflection situation will have different manifestations at different positions of the cable. Therefore, the cable under test can be analyzed based on the reflected signal.

[0039] Step 102: Process the reflected signal based on the Hilbert transform to construct an amplitude function corresponding to the reflected signal.

[0040] In one embodiment of the present application, when performing the Wigner distribution on the signal, there will be a cross-term interference problem when directly using multi-component signals. To avoid the inaccurate positioning caused by the cross-interference problem, the present application embodiment needs to separately extract two signals representing the head end and the end of the cable. Before extraction, it is first necessary to determine the amplitude function corresponding to the reflected signal. Among them, the amplitude function is a function used to describe the contour of the reflected signal.

[0041] It should be noted that when using the time-frequency domain reflectometry to locate cable defects, it is necessary to determine a detection signal of complex type to determine the amplitude function. However, the existing signal generator equipment cannot generate the imaginary part of the detection signal, so it cannot form a complex signal, and thus cannot collect a complex type signal. Therefore, after collecting the reflected signal, it is also necessary to determine the imaginary component corresponding to the reflected signal to determine the amplitude function.

[0042] Specifically, perform the Hilbert transform on the reflected signal to obtain the imaginary component corresponding to the reflected signal; among them, the imaginary component is used to describe the complex type signal corresponding to the detection signal, and its imaginary part forms a signal after reflection in the cable under test. It is represented by the following formula:

[0043]

[0044] Among them, H[r(t)] is the imaginary component, and τ is the time variable of integration.

[0045] It should also be noted that the complex type signal corresponding to the detection signal is represented by the following formula:

[0046]

[0047] Further, a formula based on a preset amplitude function is constructed to process the reflected signal and the imaginary component to obtain the amplitude function corresponding to the reflected signal. The amplitude function construction formula is determined by the following formula:

[0048]

[0049] where A m (t) is the amplitude function, r(t) is the reflected signal, and H[r(t)] is the imaginary component.

[0050] Step 103: Based on the amplitude function, determine the first signal range and the second signal range in the reflected signal, and divide the reflected signal into several segmented signals based on the first signal range and the second signal range.

[0051] In an embodiment of the present application, after determining the amplitude function, based on the amplitude function, determine the first signal range and the second signal range in the reflected signal. Among them, the first signal range is the part used to describe the reflected signal corresponding to the cable head end; the second signal range is the part used to describe the reflected signal corresponding to the cable tail end.

[0052] Specifically, determine several maximum points in the amplitude function, and determine the first maximum point and the second maximum point among the several maximum points; respectively determine two points with the absolute value of the slope equal to the preset threshold in the neighborhoods of the first maximum point and the second maximum point; based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determine the first signal range, and based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the second maximum point, determine the second signal range.

[0053] In an embodiment of the present application, based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determining the first signal range specifically includes the following steps: determining the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point as the first signal range points, and determining the time parameters corresponding to the first signal range points; based on the two time parameters corresponding to the first signal range points, determine the first time range; based on the first time range, determine the first signal range in the reflected signal.

[0054] Similarly, based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the second maximum point, determine the second signal range in the reflected signal.

[0055] It is understandable that the first maximum point is the maximum point among all extreme values, and the second maximum point is the maximum point except for the first maximum. It should be noted that due to the discontinuity between the cable head and the cable end, the amplitude of the reflected signal is the largest when the detection signal is transmitted at the cable head and the cable end; and because of the attenuation of reflection, among the received transmitted signals, the amplitude of the reflected signal part corresponding to the cable head is greater than the amplitude of the reflected signal part corresponding to the cable end. Therefore, the first signal range corresponding to the first maximum point is the reflected signal part corresponding to the cable head, and the second signal range corresponding to the second maximum point is the reflected signal part corresponding to the cable end.

[0056] In an embodiment of the present application, after determining the first signal range and the second signal range in the reflected signal, the reflected signal is divided into several segmented signals.

[0057] Step 104: Process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain the first time-frequency distribution function corresponding to the reflected signal.

[0058] In an embodiment of the present application, after dividing the reflected signal into several segmented signals, it is first necessary to process the several segmented signals through the Wigner distribution function to determine the corresponding several time-frequency distributions.

[0059] Specifically, substitute the several segmented signals into the following formula respectively:

[0060]

[0061] where W(t,ω) is the Wigner distribution function, t is time, ω is the instantaneous angular frequency of the reflected signal, τ is the autocorrelation time variable, is the complex conjugate function of.

[0062] In an embodiment of the present application, after determining the several time-frequency distributions corresponding to the several segmented signals, integrate the several time-frequency distributions into a continuous time-series time-frequency distribution to determine the first time-frequency distribution function corresponding to the reflected signal.

[0063] In an embodiment of the present application, the detection signal is also processed through the Wigner distribution function to determine the second time-frequency distribution function corresponding to the detection.

[0064] Step 105: Compare the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect location of the cable to be tested, and determine the defect degree of the defect based on a preset defect degree determination function.

[0065] In one embodiment of the present application, after determining the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function corresponding to the reflection signal based on the Wigner distribution function, the second time-frequency distribution function corresponding to the detection signal is compared with the first time-frequency distribution function corresponding to the reflection signal for correlation to determine the defect position of the cable to be measured.

[0066] Specifically, first, based on the first time-frequency distribution function and the second time-frequency distribution function, a defect location curve of the cable to be measured is determined through a preset cross-correlation function, and based on the defect location curve, a defect location point is determined; wherein, the defect location point is an extreme point on the defect location curve for describing the defect position; then, based on the time parameter corresponding to the defect location point in the defect location curve, the distance from the defect to the head end of the cable to be measured is determined.

[0067] It can be understood that there are multiple maximum values in the defect location curve; among them, the maximum value corresponding within the two time parameters of the determined first time range is the maximum value corresponding to the head end of the cable to be measured; the maximum value corresponding within the two time parameters of the determined second time range is the maximum value corresponding to the tail end of the cable to be measured, and the remaining several maximum values correspond to the positions of the defects. Based on the time parameters corresponding to the remaining several maximum values, the specific distance from the defect to the head end of the cable to be measured is determined.

[0068] It should be noted that before determining the specific distance from the defect to the head end of the cable to be measured based on the time parameters corresponding to the remaining several maximum values, the performance parameters of the cable to be measured need to be determined first, and then based on the performance parameters of the cable to be measured, the transmission speed of the reflection signal in the cable is calculated. Thus, the specific distance from the defect to the head end of the cable to be measured can be determined based on the time parameters corresponding to the remaining several maximum values.

[0069] Specifically, the transmission speed and the time parameters corresponding to the remaining several maximum values are substituted into the following formula:

[0070]

[0071] where x is the distance from the defect position to the head end of the cable to be measured, v is the transmission speed of the reflection signal on the cable, and t is the time parameter corresponding to the remaining several maximum values.

[0072] It should be noted that the cross-correlation function is represented by the following formula:

[0073]

[0074] where C(t) is the cross-correlation function of the time variable t, t′ is the time variable of integration,; T s is half of the duration of the detection signal; ω is the instantaneous angular frequency of the signal; Wr is the time-frequency distribution of the transmitted signal; W s is the time-frequency distribution of the detected signal.

[0075] It should be noted that although the existing time-domain reflectometry can accurately locate serious faults, such as open circuit and short circuit faults, it is difficult to identify weak defects; the frequency-domain reflectometry has high sensitivity and can locate weak defects, but there are many misjudgment items in the positioning curve and still needs to be improved; the positioning curve of the time-frequency domain reflectometry is relatively smooth and the defect information is easy to identify, but the amplitude of the positioning curve has no direct relationship with the severity of the defect, and it may identify defects that have no obvious impact on the power quality of the power grid, resulting in unnecessary cable section replacement. In addition, although the cross-correlation function can locate defects, the correlation amplitude between the detected signal and the reflected signal has no direct connection with the amplitude of the reflected signal itself, so it cannot be used as the basis for judging the defect degree.

[0076] Therefore, in an embodiment of the present application, after determining the defect location of the cable to be measured, the defect degree of the defect is further determined based on a preset defect degree determination function.

[0077] Among them, the defect degree determination function is determined by the following formula:

[0078]

[0079] Among them, A(t) is the defect degree determination function of the time variable t, and t′ is the time variable of integration; T s is half of the duration of the detected signal; ω is the instantaneous angular frequency of the signal; W r is the time-frequency distribution of the reflected signal; W s is the time-frequency distribution of the detected signal.

[0080] Based on the same inventive concept, an embodiment of the present application also provides a cable defect positioning device, the internal structure of which is as Figure 2 shown.

[0081] Figure 2 is a schematic diagram of the internal structure of a cable defect positioning device provided by an embodiment of the present application. As Figure 2 shown, the device includes: a processor 201; a memory 202, on which executable instructions are stored, and when the executable instructions are executed, the processor 201 executes a cable defect positioning method as described above.

[0082] In one embodiment of the present application, the processor 201 is configured to input a detection signal from the head end of the cable under test, and collect the reflected signal corresponding to the detection signal at the head end of the cable under test; process the reflected signal based on the Hilbert transform to construct an amplitude function corresponding to the reflected signal; wherein, the amplitude function is used to describe the profile of the reflected signal; based on the amplitude function, determine a first signal range and a second signal range in the reflected signal, and divide the reflected signal into several segmented signals based on the first signal range and the second signal range; wherein, the first signal range is used to describe the part of the reflected signal corresponding to the head end of the cable; the second signal range is used to describe the part of the reflected signal corresponding to the tail end of the cable; process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain a first time-frequency distribution function corresponding to the reflected signal; compare the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect location of the cable under test.

[0083] Some embodiments of the present application provide a non-volatile computer storage medium corresponding to Figure 1 for cable defect location, storing computer-executable instructions, and the computer-executable instructions are set as:

[0084] Input a detection signal from the head end of the cable under test, and collect the reflected signal corresponding to the detection signal at the head end of the cable under test;

[0085] Process the reflected signal based on the Hilbert transform to construct an amplitude function corresponding to the reflected signal; wherein, the amplitude function is used to describe the profile of the reflected signal;

[0086] Based on the amplitude function, determine a first signal range and a second signal range in the reflected signal, and divide the reflected signal into several segmented signals based on the first signal range and the second signal range; wherein, the first signal range is used to describe the part of the reflected signal corresponding to the head end of the cable; the second signal range is used to describe the part of the reflected signal corresponding to the tail end of the cable;

[0087] Process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain a first time-frequency distribution function corresponding to the reflected signal;

[0088] Compare the correlation between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect location of the cable under test.

[0089] Each embodiment in this application is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments of the Internet of Things devices and media, since they are basically similar to the method embodiments, the description is relatively simple. For the relevant parts, reference can be made to the partial description of the method embodiments.

[0090] The systems and media provided in the embodiments of this application correspond one-to-one with the methods. Therefore, the systems and media also have beneficial technical effects similar to those of their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the systems and media will not be elaborated here.

[0091] Those skilled in the art should understand that the embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) that contain computer-usable program code.

[0092] This application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of this application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0093] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0094] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, causing a series of operational steps to be performed on the computer or other programmable apparatus to generate a computer-implemented process, so that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one process Figure 1 one process or a plurality of processes and / or Figure 1 steps for implementing the functions specified in one block or a plurality of blocks.

[0095] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0096] The memory may include non-permanent memory in the computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM). The memory is an example of a computer-readable medium.

[0097] Computer-readable media includes both permanent and non-permanent, removable and non-removable media implemented by any method or technology for storing information. The information may be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission media that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0098] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or apparatus comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or apparatus. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising the element.

[0099] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

Claims

1. A method for cable defect location, characterized in that, The method includes: Input the detection signal from the head end of the cable under test, and collect the reflection signal corresponding to the detection signal at the head end of the cable under test; Process the reflection signal based on the Hilbert transform to construct an amplitude function corresponding to the reflection signal; wherein, the amplitude function is used to describe the profile of the reflection signal; Based on the amplitude function, determine a first signal range and a second signal range in the reflection signal, and divide the reflection signal into several segmented signals based on the first signal range and the second signal range; wherein, the first signal range is used to describe the reflection signal part corresponding to the head end of the cable; the second signal range is used to describe the reflection signal part corresponding to the tail end of the cable; Process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain a first time-frequency distribution function corresponding to the reflection signal; Perform a correlation comparison between the second time-frequency distribution function corresponding to the detection signal and the first time-frequency distribution function to determine the defect position of the cable under test; Processing the reflection signal based on the Hilbert transform to construct an amplitude function corresponding to the reflection signal specifically includes: Perform a Hilbert transform on the reflection signal to obtain an imaginary component corresponding to the reflection signal; wherein, the imaginary component is used to describe the complex type signal corresponding to the detection signal, and the signal part formed by reflection of its imaginary part in the cable under test; Process the reflection signal and the imaginary component based on a preset amplitude function construction formula to obtain an amplitude function corresponding to the reflection signal; Based on the amplitude function, determining the first signal range and the second signal range in the reflection signal specifically includes: Determine several maximum points in the amplitude function, and determine a first maximum point and a second maximum point among the several maximum points; Respectively determine two points with the absolute value of the slope equal to a preset threshold in the neighborhoods of the first maximum point and the second maximum point; Based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determine the first signal range, and based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the second maximum point, determine the second signal range; Based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determining the first signal range specifically includes: Determine the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point as the first signal range points, and determine the time parameters corresponding to the first signal range points; Based on the two time parameters corresponding to the first signal range points, determine a first time range; Based on the first time range, determine the first signal range in the reflection signal.

2. The cable defect location method according to claim 1, wherein, After determining the defect position of the cable under test, the method further includes: Determine the defect degree of the defect based on a preset defect degree determination function; Wherein, the defect degree determination function is determined by the following formula: Among them, A(t) is a defect degree determination function of the time variable t, and t ′ is the time variable of integration; T s is half of the detection signal duration; ω is the instantaneous angular frequency of the signal; W r is the time-frequency distribution of the reflected signal; W s is the time-frequency distribution of the detection signal.

3. A cable defect location method according to claim 1, characterized in that, The amplitude function construction formula is determined by the following formula: Among them, A m (t) is the amplitude function, r(t) is the reflected signal, and H[r(t)] is the imaginary component.

4. A cable defect location method according to claim 1, characterized in that, Compare the second time-frequency distribution function corresponding to the detection signal with the first time-frequency distribution function to determine the defect position of the cable to be measured, specifically including: Based on the first time-frequency distribution function and the second time-frequency distribution function, determine the defect location curve of the cable to be measured through a preset cross-correlation function, and based on the defect location curve, determine the defect location point; wherein, the defect location point is the extreme value point on the defect location curve used to describe the defect position; Based on the time parameter corresponding to the defect location point in the defect location curve, determine the distance from the defect to the head end of the cable to be measured.

5. A method for cable defect location according to claim 4, characterized in that, Before determining the distance from the defect to the head end of the cable based on the time parameter corresponding to the defect location point in the defect location curve, the method further includes: Determine the performance parameters of the cable to be measured; Based on the performance parameters of the cable to be measured, calculate the transmission speed of the reflection signal in the cable.

6. A cable defect location device, characterized in that, The device includes: A processor; And a memory, on which executable code is stored, and when the executable code is executed, the processor executes the method according to any one of claims 1-5.

7. A non-volatile computer storage medium for cable defect location, storing computer-executable instructions, characterized in that, The computer executable instructions are set to: Input the detection signal from the head end of the cable to be measured, and collect the reflection signal corresponding to the detection signal at the head end of the cable to be measured; Process the reflection signal based on the Hilbert transform to construct the amplitude function corresponding to the reflection signal; wherein, the amplitude function is used to describe the profile of the reflection signal; Based on the amplitude function, determine the first signal range and the second signal range in the reflection signal, and based on the first signal range and the second signal range, divide the reflection signal into several segmented signals; wherein, the first signal range is used to describe the reflection signal part corresponding to the head end of the cable; the second signal range is used to describe the reflection signal part corresponding to the tail end of the cable; Process the several segmented signals through the Wigner distribution function to obtain corresponding several time-frequency distributions, and integrate the several time-frequency distributions to obtain the first time-frequency distribution function corresponding to the reflection signal; Compare the second time-frequency distribution function corresponding to the detection signal with the first time-frequency distribution function to determine the defect position of the cable to be measured; Process the reflection signal based on the Hilbert transform to construct the amplitude function corresponding to the reflection signal, specifically including: Perform the Hilbert transform on the reflection signal to obtain the imaginary component corresponding to the reflection signal; wherein, the imaginary component is used to describe the complex type signal corresponding to the detection signal, and the imaginary part of which is the signal part formed by reflection in the cable to be measured; Process the reflection signal and the imaginary component based on a preset amplitude function construction formula to obtain the amplitude function corresponding to the reflection signal; Based on the amplitude function, determine the first signal range and the second signal range in the reflection signal, specifically including: Determine several maximum value points in the amplitude function, and determine the first maximum value point and the second maximum value point among the several maximum values; Determine two points with the absolute value of the slope equal to the preset threshold in the neighborhoods of the first maximum point and the second maximum point respectively; Based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determine the first signal range, and based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the second maximum point, determine the second signal range; Based on the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point, determining the first signal range specifically includes: Determine the two points with the absolute value of the slope equal to the preset threshold corresponding to the first maximum point as the first signal range points, and determine the time parameters corresponding to the first signal range points; Based on the two time parameters corresponding to the first signal range points, determine the first time range; Based on the first time range, determine the first signal range in the reflected signal.

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