A cable breakage monitoring device and method

Abstract

The application provides a cable breakage monitoring device and a detection method, and relates to the technical field of electricity.The cable breakage monitoring device provided by the application comprises a cable core, at least two piezoelectric friction layers and a control module; the at least two piezoelectric friction layers are wrapped around the periphery of the cable core and are electrically connected with the control module, are used for generating corresponding piezoelectric signals when the cable core is subjected to external force, and are used for sending at least two piezoelectric signals to the control module; and the control module is used for determining the stress condition of the cable according to the at least two piezoelectric signals.The cable breakage monitoring device provided by the application is provided with at least two piezoelectric friction layers around the periphery of the cable core, the multiple piezoelectric friction layers can respectively detect the stress conditions of the surface layer of the cable and the inside of the cable, the data obtained by the monitoring device is more comprehensive and accurate, and thus the stress condition and the breakage condition of the cable can be more accurately obtained.

Description

Technical Field

[0001] This invention relates to the field of electrical technology, and in particular to a monitoring device and detection method for cable damage. Background Technology

[0002] Damage or breakage of the cable sheath has a significant impact on the transmission of signals and power, and can even create safety hazards such as electric shock, electromagnetic interference, and short circuits, affecting the normal operation of equipment. Therefore, monitoring the integrity of cables is of great importance. Existing online cable monitoring solutions, such as image monitoring, have limited applicability, low monitoring accuracy and precision, are easily affected by weather, and cannot monitor cables in cable trenches or buried underground. Meanwhile, some commonly used detection technologies, such as infrared thermal imaging and ultrasonic testing, have their own limitations, and these technologies are also difficult to use for real-time online cable monitoring. Summary of the Invention

[0003] This invention provides a monitoring device and detection method for cable damage, which can detect the stress on the surface and inside of the cable, thereby obtaining more accurate information on the cable stress and damage.

[0004] In a first aspect, embodiments of the present invention provide a cable damage monitoring device, wherein the cable includes a cable core, and the monitoring device includes at least two piezoelectric friction layers and a control module;

[0005] At least two piezoelectric friction layers are wrapped around the cable core and electrically connected to the control module. They are used to generate corresponding piezoelectric signals when the cable core is subjected to external force and to send at least two piezoelectric signals to the control module.

[0006] The control module is used to determine the stress on the cable based on at least two piezoelectric signals.

[0007] Optionally, the cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core.

[0008] At least two piezoelectric friction layers, including a first piezoelectric friction layer and a second piezoelectric friction layer;

[0009] The first piezoelectric friction layer is wrapped around the first cable core and is used to generate a first piezoelectric signal when the first cable core is subjected to external force, and to send the first piezoelectric signal to the control module;

[0010] The second piezoelectric friction layer is wrapped around the second cable core and located inside the first cable core. It is used to generate a second piezoelectric signal when the second cable core is subjected to external force and to send the second piezoelectric signal to the control module.

[0011] The control module is used to determine the stress on the cable based on the first piezoelectric signal and the second piezoelectric signal.

[0012] Optionally, the monitoring device further includes a first electrode and a second electrode, both of which are spirally arranged along the extension direction of the cable core; both the first electrode and the second electrode are disposed on the outside of the first piezoelectric friction layer and are electrically connected to the control module for transmitting the first piezoelectric signal to the control module.

[0013] And / or, the monitoring device further includes a third electrode and a fourth electrode, which are spirally arranged along the extension direction of the cable core; both the third electrode and the fourth electrode are located on the outside of the second piezoelectric friction layer and are electrically connected to the control module for transmitting the second piezoelectric signal to the control module.

[0014] Optionally, the first piezoelectric friction layer includes at least one first piezoelectric friction partition; the monitoring device further includes a fifth electrode and a sixth electrode, which are disposed at both ends of the first piezoelectric friction partition along the extension direction of the cable core and are electrically connected to the control module to transmit the first piezoelectric signal generated by the first piezoelectric friction partition to the control module.

[0015] And / or, the second piezoelectric friction layer includes at least one second piezoelectric friction partition; the monitoring device further includes a seventh electrode and an eighth electrode, which are disposed at both ends of the second piezoelectric friction partition along the extension direction of the cable core, and are electrically connected to the control module to transmit the second piezoelectric signal generated by the second piezoelectric friction partition to the control module.

[0016] Optionally, the cable core may also include a third cable core disposed within the second cable core;

[0017] The piezoelectric friction layer also includes a third piezoelectric friction layer;

[0018] The third piezoelectric friction layer is wrapped around the third cable core and located inside the second cable core. It is electrically connected to the control module and is used to generate a third piezoelectric signal when the third cable core is subjected to external force, and to send the third piezoelectric signal to the control module.

[0019] The control module is also used to determine the stress on the cable based on the first piezoelectric signal, the second piezoelectric signal, and the third piezoelectric signal.

[0020] Optionally, the monitoring device may also include an alarm module and a display module;

[0021] The control module is also connected to the alarm module to send an alarm signal to the alarm module when the piezoelectric signal exceeds the piezoelectric signal threshold.

[0022] The alarm module is used to issue an alarm upon receiving an alarm signal;

[0023] The control module also communicates with the display module to send cable status signals to the display module;

[0024] The display module is used to display the status information of the cable based on the status signals.

[0025] Secondly, embodiments of the present invention provide a method for monitoring cable damage, applicable to the monitoring device provided in any embodiment of the present invention. The monitoring method includes:

[0026] Obtain at least two piezoelectric signals output from at least two piezoelectric friction layers;

[0027] The stress on the cable is determined based on at least two piezoelectric signals.

[0028] Optionally, the cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core.

[0029] At least two piezoelectric friction layers, including a first piezoelectric friction layer and a second piezoelectric friction layer;

[0030] At least two piezoelectric signals include a first voltage signal output by the first piezoelectric friction layer and a second piezoelectric signal output by the second piezoelectric friction layer;

[0031] The stress on the cable is determined based on at least two piezoelectric signals, including:

[0032] A first frequency domain signal is obtained by performing a frequency domain transformation on the first piezoelectric signal, and a second frequency domain signal is obtained by performing a frequency domain transformation on the second piezoelectric signal.

[0033] The degree of cable damage is determined based on the extent to which the first frequency domain signal deviates from the first preset frequency range, and / or the extent to which the second frequency domain signal deviates from the second preset frequency range.

[0034] Optionally, the cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core.

[0035] At least two piezoelectric friction layers, including a first piezoelectric friction layer and a second piezoelectric friction layer;

[0036] At least two piezoelectric signals include a first voltage signal output by the first piezoelectric friction layer and a second piezoelectric signal output by the second piezoelectric friction layer;

[0037] The stress on the cable is determined based on at least two piezoelectric signals, including:

[0038] The stress position of the cable is determined based on the receiving order of the first and second piezoelectric signals.

[0039] Optionally, after acquiring at least two piezoelectric signals output from at least two piezoelectric friction layers, the method further includes:

[0040] Filter at least two piezoelectric signals;

[0041] At least two filtered piezoelectric signals are amplified to obtain at least two amplified signals;

[0042] Denoise the at least two amplified signals;

[0043] Normalize at least two amplified signals after noise reduction and perform time synchronization on at least two amplified signals.

[0044] The cable damage monitoring device provided in this invention has at least two piezoelectric friction layers around the cable core. When the cable is subjected to external force, the piezoelectric friction layers generate piezoelectric signals, enabling real-time monitoring of the cable's stress condition. Furthermore, the control module can determine the risk of cable damage and the location of any damage based on the piezoelectric signals. In addition, the multiple piezoelectric friction layers can detect the stress on the cable surface and inside the cable separately, making the data obtained by the monitoring device more comprehensive and accurate, thus providing a more precise understanding of the cable's stress and damage status.

[0045] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the structure of a cable damage monitoring device provided in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the structure of the first piezoelectric friction layer, the first electrode, and the second electrode provided in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the axial structure of the first piezoelectric friction layer, the first electrode, and the second electrode provided in an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the structure of the second piezoelectric friction layer, the third electrode, and the fourth electrode provided in an embodiment of the present invention;

[0051] Figure 5 This is an axial structural schematic diagram of the second piezoelectric friction layer, the third electrode, and the fourth electrode provided in an embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of the structure of the first piezoelectric friction layer, the fifth electrode, and the sixth electrode provided in an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the structure of the second piezoelectric friction layer, the seventh electrode, and the eighth electrode provided in an embodiment of the present invention;

[0054] Figure 8 This is a schematic diagram of the structure of the second cable core provided in an embodiment of the present invention;

[0055] Figure 9 This is a structural block diagram of the detection device provided in the embodiments of the present invention;

[0056] Figure 10 This is a flowchart of a cable damage monitoring method provided in an embodiment of the present invention;

[0057] Figure 11 This is a flowchart of another cable damage monitoring method provided in an embodiment of the present invention;

[0058] Figure 12 This is a flowchart of another cable damage monitoring method provided in an embodiment of the present invention;

[0059] Figure 13 This is a flowchart of another cable damage monitoring method provided in an embodiment of the present invention. Detailed Implementation

[0060] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0061] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatuses.

[0062] This invention provides a cable damage monitoring device. Figure 1 This is a schematic diagram of the structure of a cable damage monitoring device provided in an embodiment of the present invention, for reference. Figure 1 The cable includes a cable core 100, and the monitoring device includes at least two piezoelectric friction layers 200 and a control module. Figure 1 (not shown in the image); at least two piezoelectric friction layers 200 are wrapped around the cable core 100 and electrically connected to the control module, used to generate corresponding piezoelectric signals when the cable core 100 is subjected to external force, and send at least two piezoelectric signals to the control module; the control module is used to determine the stress condition of the cable based on the at least two piezoelectric signals.

[0063] refer to Figure 1 The piezoelectric friction layer 200 outputs piezoelectric signals when it experiences friction with the external environment and is subjected to pressure. The magnitude of the piezoelectric signal is positively correlated with the force applied to the piezoelectric friction layer 200; the greater the force applied to the piezoelectric friction layer 200, the stronger the piezoelectric signal. The piezoelectric friction layer 200 is composed of piezoelectric and triboelectric materials. The piezoelectric material generates an electrical signal when subjected to pressure, and the triboelectric material generates an electrical signal through charge separation caused by friction. The piezoelectric friction layer 200 possesses both of these characteristics. For example, polyvinylidene fluoride (PVDF) has both piezoelectric and triboelectric properties and can be used to manufacture the piezoelectric friction layer 200. Since the piezoelectric friction layer 200 is wrapped around the cable core 100, it also generates a piezoelectric signal when the cable is subjected to external force. This piezoelectric signal is transmitted to the control module. The control module can infer the stress on the cable based on the amplitude and waveform of the piezoelectric signal. If the amplitude of the piezoelectric signal exceeds a threshold, it indicates that the stress on the cable exceeds the cable's stress limit, and the cable may break. The threshold is a value used to determine whether the stress on a cable exceeds its stress limit, and it is usually determined based on experimental data.

[0064] The cable damage monitoring device provided in this invention has at least two piezoelectric friction layers around the cable core. When the cable is subjected to external force, the piezoelectric friction layers generate piezoelectric signals, enabling real-time monitoring of the cable's stress condition. Furthermore, the control module can determine the risk of cable damage and the location of any damage based on the piezoelectric signals. In addition, the multiple piezoelectric friction layers can detect the stress on the cable surface and inside the cable separately, making the data obtained by the monitoring device more comprehensive and accurate, thus providing a more precise understanding of the cable's stress and damage status.

[0065] Continue to refer to Figure 1The cable core 100 includes a first cable core 101 and a second cable core 102, with the first cable core 101 wrapped around the second cable core 102; at least two piezoelectric friction layers 200 include a first piezoelectric friction layer 201 and a second piezoelectric friction layer 202; the first piezoelectric friction layer 201 wraps around the first cable core 101 and is used to generate a first piezoelectric signal when the first cable core 101 is subjected to an external force, and to send the first piezoelectric signal to the control module. Figure 1 (not shown in the image); the second piezoelectric friction layer 202 wraps around the second cable core 102 and is located inside the first cable core 101. It is used to generate a second piezoelectric signal when the second cable core 102 is subjected to an external force, and to send the second piezoelectric signal to the control module. The control module is used to determine the stress condition of the cable based on the first piezoelectric signal and the second piezoelectric signal.

[0066] refer to Figure 1 The first cable core 101 is surrounded by a first piezoelectric friction layer 201. This layer detects the stress on the first cable core 101 and generates a corresponding first piezoelectric signal based on this stress. The first cable core 101 is wrapped around a second cable core 102. It is understood that the number of second cable cores 102 is determined based on the actual cable structure. Figure 1 The cable shown includes two second cores 102. Each second core 102 is surrounded by a second piezoelectric friction layer 202. When a second core 102 is subjected to external force, the corresponding second piezoelectric friction layer 202 generates a corresponding second piezoelectric signal. After receiving the first and second piezoelectric signals, the control module can determine the location of the cable stress based on the amplitude and waveform of the first and second piezoelectric signals, and analyze the possible location of damage. The multi-layered piezoelectric friction layer can detect the stress on the cable surface and inside the cable separately, making the data obtained by the monitoring device more comprehensive and accurate, thereby obtaining a more accurate understanding of the cable stress and damage status.

[0067] Figure 2 This is a schematic diagram of the structure of the first piezoelectric friction layer, the first electrode, and the second electrode provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of the axial structure of the first piezoelectric friction layer, the first electrode, and the second electrode provided in an embodiment of the present invention, with reference to... Figure 2 and Figure 3 The monitoring device also includes a first electrode 301 and a second electrode 302. Both the first electrode 301 and the second electrode 302 are spirally arranged along the extension direction of the cable core, which is wrapped inside the first piezoelectric friction layer 201. The extension direction of the cable core is the first direction X. Both the first electrode 301 and the second electrode 302 are disposed outside the first piezoelectric friction layer 201 and are electrically connected to the control module for transmitting the first piezoelectric signal to the control module; and / or, Figure 4This is a schematic diagram of the structure of the second piezoelectric friction layer, the third electrode, and the fourth electrode provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the axial structure of the second piezoelectric friction layer, the third electrode, and the fourth electrode provided in an embodiment of the present invention, with reference to... Figure 4 and Figure 5 The monitoring device also includes a third electrode 303 and a fourth electrode 304, which are spirally arranged along the extension direction of the cable core. The cable core is wrapped inside the second piezoelectric friction layer 202, and the extension direction of the cable core is the first direction X. The third electrode 303 and the fourth electrode 304 are both arranged on the outside of the second piezoelectric friction layer 202 and are both electrically connected to the control module to transmit the second piezoelectric signal to the control module.

[0068] refer to Figure 2 and Figure 3 The first cable core 101 is wrapped inside the first piezoelectric friction layer 201. When subjected to external force, the first piezoelectric friction layer 201 generates charges of opposite polarity, thus forming a voltage within it. A first electrode 301 and a second electrode 302 are respectively disposed on the first piezoelectric friction layer 201, with the first electrode 301 located on the outer side and the second electrode 302 on the inner side. The direction of the current generated by the first piezoelectric friction layer 201 after being subjected to force is related to its polarization direction. In this embodiment, the first piezoelectric friction layer 201 generates charges of opposite polarity on its inner and outer sides after being subjected to force. The first electrode 301 and the second electrode 302 transmit these charges of opposite polarity to the control module. These charges of opposite polarity form a first piezoelectric signal, which the control module can use to determine the force applied to the first piezoelectric friction layer 201. Similarly, refer to... Figure 4 and Figure 5 The second cable core 102 is wrapped inside the second piezoelectric friction layer 202. When subjected to external force, the second piezoelectric friction layer 202 also generates charges of opposite polarity. The third electrode 303 is located outside the second piezoelectric friction layer 202, and the fourth electrode 304 is located inside. In this embodiment, when the second piezoelectric friction layer 202 is subjected to force, it generates charges of opposite polarity on its inner and outer sides, respectively. The third electrode 303 and the fourth electrode 304 transmit these charges of opposite polarity to the control module. These charges of opposite polarity form a second piezoelectric signal, which the control module can use to determine the force applied to the second piezoelectric friction layer 202. Setting the electrodes in a spiral shape increases the contact area between the electrodes and the piezoelectric friction layer, which is beneficial for the electrodes to transmit the piezoelectric signal generated by the piezoelectric friction layer to the control module. Furthermore, the spiral-shaped electrodes are more elastic, can withstand greater external force, and have a longer service life.

[0069] Figure 6This is a schematic diagram of the structure of the first piezoelectric friction layer, the fifth electrode, and the sixth electrode provided in an embodiment of the present invention, with reference to... Figure 6 The first piezoelectric friction layer includes at least one first piezoelectric friction partition 2011; the monitoring device further includes a fifth electrode 305 and a sixth electrode 306, which are disposed at both ends of the first piezoelectric friction partition 2011 along the extension direction of the cable core. The cable core is wrapped inside the first piezoelectric friction layer, and the extension direction of the cable core is the first direction X. Both the fifth electrode 305 and the sixth electrode 306 are electrically connected to the control module for transmitting the first piezoelectric signal generated by the first piezoelectric friction partition 2011 to the control module; and / or, Figure 7 This is a schematic diagram of the structure of the second piezoelectric friction layer, the seventh electrode, and the eighth electrode provided in an embodiment of the present invention. (Refer to...) Figure 7 The second piezoelectric friction layer 202 includes at least one second piezoelectric friction partition 2021; the monitoring device also includes a seventh electrode 307 and an eighth electrode 308, which are disposed at both ends of the second piezoelectric friction partition 2021 along the extension direction of the cable core. The cable core is wrapped inside the second piezoelectric friction layer, and the extension direction of the cable core is the first direction X. Both are electrically connected to the control module to transmit the second piezoelectric signal generated by the second piezoelectric friction partition 2021 to the control module.

[0070] refer to Figure 6 The first piezoelectric friction layer is divided into at least one first piezoelectric friction partition 2011. In this embodiment, when the first piezoelectric friction partition 2011 is subjected to external force, it generates charges of opposite polarities at its two ends, thereby forming a voltage within the first piezoelectric friction partition 2011. The fifth electrode 305 and the sixth electrode 306 are respectively disposed at both ends of the same first piezoelectric friction partition 2011, thereby transmitting the voltage signal generated by the first piezoelectric friction partition 2011 to the control module. This voltage signal is the first piezoelectric signal. Each first piezoelectric friction partition 2011 has a fifth electrode 305 and a sixth electrode 306 at both ends. There is an insulating layer between the fifth electrode 305 and the sixth electrode 306 in different first piezoelectric friction partitions 2011. The fifth electrode 305 and the sixth electrode 306 can only transmit the electrical signal generated by the first piezoelectric friction partition 2011 in which they are located. The control module can determine the force on the first piezoelectric friction layer based on the first piezoelectric signal. Similarly, refer to Figure 7The second piezoelectric friction layer 202 is divided into at least one second piezoelectric friction partition 2021. In this embodiment, when the second piezoelectric friction partition 2021 is subjected to external force, it generates charges of opposite polarities at both ends, thereby forming a voltage within the second piezoelectric friction partition 2021. The seventh electrode 307 and the eighth electrode 308 are respectively disposed at both ends of the same second piezoelectric friction partition 2021, thereby transmitting the voltage signal generated by the second piezoelectric friction partition 2021 to the control module. This voltage signal is the second piezoelectric signal. Each second piezoelectric friction partition 2021 has a seventh electrode 307 and an eighth electrode 308 at both ends. There is an insulating layer between the seventh electrode 307 and the eighth electrode 308 in different second piezoelectric friction partitions 2021. The seventh electrode 307 and the eighth electrode 308 can only transmit the electrical signal generated by the second piezoelectric friction partition 2021 in which they are located. The control module can determine the force on the second piezoelectric friction layer 202 based on the second piezoelectric signal.

[0071] Dividing the first and second piezoelectric friction layers into at least one partition allows the electrodes to acquire the piezoelectric signals generated by the first and second piezoelectric friction layers in segments. This enables the control module to accurately determine the location where the piezoelectric signals are generated. Furthermore, since the extension length of each partition is relatively short, the piezoelectric signals acquired by the electrodes are subject to less interference, thus allowing the piezoelectric signals to more accurately reflect the stress conditions of the first and second piezoelectric friction layers.

[0072] Figure 8 This is a schematic diagram of the structure of the second cable core provided in an embodiment of the present invention, for reference. Figure 8 The cable core 100 also includes a third cable core 103, which is disposed inside the second cable core 102; the piezoelectric friction layer 200 also includes a third piezoelectric friction layer 203; the third piezoelectric friction layer 203 is wrapped around the third cable core 103 and located inside the second cable core 102, and is electrically connected to the control module, for generating a third piezoelectric signal when the third cable core 103 is subjected to external force, and sending the third piezoelectric signal to the control module; the control module is also used to determine the stress condition of the cable based on the first piezoelectric signal, the second piezoelectric signal and the third piezoelectric signal.

[0073] refer to Figure 8The third cable core 103 is located inside the second cable core 102. The number of third cable cores 103 is determined by the actual structure of the cable. Each third cable core 103 is surrounded by a third piezoelectric friction layer 203. When subjected to external force, the third piezoelectric friction layer 203 generates a third piezoelectric signal. After receiving the first, second, and third piezoelectric signals, the control module can determine the location of the cable stress and analyze the possible damage location based on the amplitude and waveform of the first, second, and third piezoelectric signals. The multi-layer piezoelectric friction layer can detect the stress on the cable surface and inside the cable separately, making the data obtained by the monitoring device more comprehensive and accurate, thereby obtaining a more accurate cable stress and damage status.

[0074] Figure 9 This is a structural block diagram of the detection device provided in an embodiment of the present invention, with reference to... Figure 9 The monitoring device also includes an alarm module 500 and a display module 600; the control module 400 is also communicatively connected to the alarm module 500 and is used to send an alarm signal to the alarm module 500 when the piezoelectric signal exceeds the piezoelectric signal threshold; the alarm module 500 is used to sound an alarm after receiving the alarm signal; the control module 400 is also communicatively connected to the display module 600 and is used to send the cable status signal to the display module 600; the display module 600 is used to display the cable status information according to the status signal.

[0075] refer to Figure 9 After the piezoelectric friction layer 200 sends a piezoelectric signal to the control module 400, the control module 400 determines the stress on the cable based on the piezoelectric signal. The piezoelectric signal threshold is a value used to determine whether the cable is at risk of damage. When the piezoelectric signal exceeds the threshold, the cable is at risk of damage, and the control module 400 activates the alarm module 500 to sound an alarm, allowing staff to be aware of the potential damage risk and enabling timely repair. The display module 600 receives and displays various status data of the cable, allowing staff to monitor the cable's real-time status at any time.

[0076] Based on the same inventive concept, embodiments of the present invention provide a method for monitoring cable damage, applicable to the monitoring device provided in any embodiment of the present invention. Figure 10 This is a flowchart of a cable damage monitoring method provided in an embodiment of the present invention, referred to as [reference]. Figure 10 Monitoring methods include:

[0077] S101. Obtain at least two piezoelectric signals output from at least two piezoelectric friction layers.

[0078] When the piezoelectric friction layer generates friction with the outside world and is subjected to pressure, it will output a piezoelectric signal. The magnitude of the piezoelectric signal is positively correlated with the force on the piezoelectric friction layer. The greater the force on the piezoelectric friction layer, the higher the intensity of the piezoelectric signal.

[0079] S102. Determine the stress condition of the cable based on at least two piezoelectric signals.

[0080] At least two piezoelectric friction layers can detect the stress on the outside and inside of the cable respectively and generate piezoelectric signals. The control module can analyze the stress on the cable based on multiple piezoelectric signals, and can also detect the damage on the outside and inside of the cable, so as to achieve comprehensive detection of cable damage and improve the accuracy of detection.

[0081] Generally, the larger the piezoelectric signal amplitude, the greater the external force on the cable. If the piezoelectric signal amplitude exceeds a threshold, it indicates that the cable is under stress beyond its limit, and the cable may break. After cable breakage, the more severe the damage, the more pronounced the change in piezoelectric signal amplitude. Minor cable damage results in small fluctuations in the piezoelectric signal amplitude, while severe damage causes a significant drop or abnormal increase. This is because damage to the cable sheath allows the internal conductors to come into contact with the external environment, leading to leakage or interference in the piezoelectric signal, resulting in significant amplitude changes. Furthermore, the piezoelectric signal pulse width varies depending on the degree of cable damage. The more severe the damage, the greater the change in pulse width. Cable sheath damage also alters the signal duration. For minor damage, the piezoelectric signal duration may fluctuate slightly; however, severe damage may cause interruptions or a significant shortening of the signal duration. This is because severe damage can obstruct signal transmission or result in partial signal loss. Optionally, the collected piezoelectric signals and damage records can be stored in a database for subsequent analysis and historical data retrieval. Furthermore, an artificial neural network model, such as a convolutional neural network or a recurrent neural network, can be constructed. Using piezoelectric signal features as input, the trained neural network can learn the characteristic differences between the piezoelectric signals of normal cables and damaged cables, thereby accurately determining whether the cable has outer sheath damage and the degree of damage.

[0082] The monitoring method provided in this invention can determine the stress on a cable by analyzing the amplitude and waveform of the piezoelectric signal, and can determine the degree of cable damage based on the changes in the piezoelectric signal.

[0083] The piezoelectric friction layer generates piezoelectric signals because it is subjected to pressure or relative friction. Complex environments, such as railway tracks or construction sites, experience continuous and irregular vibrations. These vibrations cause the cables attached to the surface to continuously experience external forces. While these forces do not damage the cables, they can interfere with the monitoring of cable damage. To eliminate environmental interference, this invention provides a method for monitoring cable damage. Figure 11 This is a flowchart of another cable damage monitoring method provided by an embodiment of the present invention, based on the above embodiments. Figure 11 The detection method shown further explains how to analyze the stress on the cable based on the frequency domain characteristics of the first and second piezoelectric signals. (Refer to...) Figure 11 Monitoring methods include:

[0084] S201. Obtain the first voltage signal output by the first piezoelectric friction layer and the second piezoelectric signal output by the second piezoelectric friction layer.

[0085] Specifically, the cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core. At least two piezoelectric friction layers include a first piezoelectric friction layer and a second piezoelectric friction layer. The first piezoelectric friction layer wraps around the first cable core, and the second piezoelectric friction layer wraps around the second cable core. The first piezoelectric friction layer outputs a first piezoelectric signal, and the second piezoelectric friction layer outputs a second piezoelectric signal.

[0086] S202. Perform frequency domain transformation on the first piezoelectric signal to obtain a first frequency domain signal, and perform frequency domain transformation on the second piezoelectric signal to obtain a second frequency domain signal.

[0087] For example, short-time Fourier transform or wavelet transform can be used to perform frequency domain transformation on the first piezoelectric signal and the second piezoelectric signal to capture the changes in time and frequency of the first piezoelectric signal and the second piezoelectric signal.

[0088] S203. Determine the degree of cable damage based on the degree to which the first frequency domain signal deviates from the first preset frequency range, and / or the degree to which the second frequency domain signal deviates from the second preset frequency range.

[0089] The first and second preset frequency ranges are numerical ranges used to determine whether the cable is damaged. They are usually determined based on experimental data and historical data of piezoelectric signals.

[0090] Specifically, regardless of the cable's environment, the first and second piezoelectric signals of a normal cable will have a stable energy distribution within a specific frequency range. When the cable sheath is damaged, new frequency components will be generated in the first and second piezoelectric signals, or the original characteristic frequencies of the first and second piezoelectric signals will shift. Minor cable damage will slightly increase the high-frequency components in the first and second piezoelectric signals because some local electromagnetic wave scattering or reflection may occur at the point of damage, introducing high-frequency noise. When the cable is severely damaged, the low-frequency components of the first and second piezoelectric signals may change because the cable damage causes significant changes in parameters such as the equivalent capacitance and equivalent inductance during signal transmission, thus affecting the low-frequency characteristics of the first and second piezoelectric signals. Optionally, the characteristic range of the piezoelectric signal under normal conditions can be determined by analyzing experimental data. For example, the state of the cable can be determined based on the variance of the first piezoelectric signal and the second piezoelectric signal. When the variance of the first piezoelectric signal and the second piezoelectric signal exceeds a certain multiple of the normal variance, or when the energy at a specific frequency exceeds a set threshold, it is considered that damage has occurred.

[0091] Furthermore, after the cable sheath is damaged, the bandwidth of the first and second piezoelectric signals typically widens. The more severe the cable damage, the wider the bandwidth of the first and second piezoelectric signals. This is because damage generates more harmonics and interference, thus expanding the frequency distribution range of the piezoelectric signals. Cable damage is also reflected in the frequency response curve of the piezoelectric signals. If the cable sheath is damaged, the curve will be distorted. Minor damage causes small fluctuations or peak changes in the frequency response curve at certain frequency points; severe damage results in significant deformation, peak shifts, or the appearance of new peaks and troughs. The control module can assess the changes in the first and second piezoelectric signals based on the variance of the piezoelectric signals. When the variance of the piezoelectric signals exceeds a variance threshold, damage is considered to have occurred. The variance threshold is determined based on experimental data. Therefore, the control module can determine the degree of cable damage based on the first and second frequency domain signals.

[0092] The monitoring method provided in this invention analyzes the changes in the first frequency domain signal and the second frequency domain signal to determine whether the cable is damaged and the degree of damage in the presence of external environmental interference, thereby enabling the monitoring of the cable condition in a complex environment.

[0093] Figure 12 This is a flowchart of another cable damage monitoring method provided by an embodiment of the present invention, based on the above embodiments. Figure 12 The detection method shown further explains how to determine the location of cable damage. (Refer to...) Figure 12 Monitoring methods include:

[0094] S301. Obtain the first voltage signal output by the first piezoelectric friction layer and the second piezoelectric signal output by the second piezoelectric friction layer.

[0095] Specifically, the cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core. At least two piezoelectric friction layers include a first piezoelectric friction layer and a second piezoelectric friction layer. The first piezoelectric friction layer wraps around the first cable core, and the second piezoelectric friction layer wraps around the second cable core. The first piezoelectric friction layer outputs a first piezoelectric signal, and the second piezoelectric friction layer outputs a second piezoelectric signal.

[0096] S302. Determine the stress position of the cable according to the receiving order of the first piezoelectric signal and the second piezoelectric signal.

[0097] Specifically, since the first cable core is wrapped around the second cable core, and the second piezoelectric friction layer is located inside the first piezoelectric friction layer, the control module can calculate the approximate location of the damage point from the monitoring point based on the chronological order of the changes in the received first and second piezoelectric signals. For example, if the transmission speed of the first piezoelectric signal is greater than the transmission speed of the second piezoelectric signal, the location of the damage point can be calculated based on the transmission speeds of the first and second piezoelectric signals and the time difference between the first and second piezoelectric signals received by the control module.

[0098] The monitoring method provided in this invention can calculate the location information of the cable breakage point by analyzing the receiving order of the first piezoelectric signal and the transmission speed of the first piezoelectric signal and the second piezoelectric signal, thereby enabling rapid location and eliminating the need for step-by-step investigation, saving manpower and time costs.

[0099] Figure 13 This is a flowchart of another cable damage monitoring method provided by an embodiment of the present invention, based on the above embodiments. Figure 13 The detection method shown further explains how to preprocess piezoelectric signals to facilitate analysis. (Refer to...) Figure 13 Monitoring methods include:

[0100] S401. Obtain at least two piezoelectric signals output from at least two piezoelectric friction layers.

[0101] S402. Filter at least two piezoelectric signals.

[0102] Specifically, piezoelectric signals may contain various noises and interferences. Based on the frequency characteristics of the piezoelectric signal, noise frequency components unrelated to the outer skin damage signal can be filtered out, while noise frequency components related to the outer skin damage signal can be retained.

[0103] S403. Amplify at least two filtered piezoelectric signals to obtain at least two amplified signals.

[0104] Specifically, since the acquired piezoelectric signals are usually quite weak, they need to be amplified to a processable range for subsequent analysis.

[0105] S404. Perform noise reduction processing on at least two amplified signals.

[0106] For example, digital signal processing algorithms and wavelet denoising algorithms are used to further denoise the piezoelectric signal, removing residual noise after filtering and improving the signal-to-noise ratio of the piezoelectric signal.

[0107] S405. Normalize at least two amplified signals after noise reduction and perform time synchronization processing on at least two amplified signals.

[0108] Each amplified signal is normalized to fall within the same numerical range, such as [0,1] or [-1,1], to facilitate subsequent analysis and processing and eliminate the influence of piezoelectric signal amplitude differences caused by factors such as differences in sensor sensitivity and line transmission losses. Next, time synchronization processing is performed on each amplified signal to eliminate time delays.

[0109] The monitoring method provided in this invention improves the signal-to-noise ratio of piezoelectric signals by filtering, amplifying, denoising, normalizing, and synchronizing the piezoelectric signals, eliminates the time delay between piezoelectric signals, eliminates the amplitude differences between piezoelectric signals, improves the readability of each piezoelectric signal, and reduces the difficulty of analyzing piezoelectric signals.

[0110] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A monitoring device for cable damage, wherein the cable includes a cable core, characterized in that, The monitoring device includes at least two piezoelectric friction layers and a control module; At least two piezoelectric friction layers are wrapped around the cable core and electrically connected to the control module to generate corresponding piezoelectric signals when the cable core is subjected to external force, and to send at least two piezoelectric signals to the control module. The control module is used to determine the stress on the cable based on at least two of the piezoelectric signals.

2. The monitoring device according to claim 1, characterized in that, The cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core. The at least two piezoelectric friction layers include a first piezoelectric friction layer and a second piezoelectric friction layer; The first piezoelectric friction layer is wrapped around the first cable core and is used to generate a first piezoelectric signal when the first cable core is subjected to external force, and to send the first piezoelectric signal to the control module; The second piezoelectric friction layer is wrapped around the second cable core and located inside the first cable core, and is used to generate a second piezoelectric signal when the second cable core is subjected to external force, and send the second piezoelectric signal to the control module; The control module is used to determine the stress on the cable based on the first piezoelectric signal and the second piezoelectric signal.

3. The monitoring device according to claim 2, characterized in that, The monitoring device further includes a first electrode and a second electrode, both of which are spirally arranged along the extension direction of the cable core; both the first electrode and the second electrode are disposed on the outside of the first piezoelectric friction layer and are electrically connected to the control module for transmitting the first piezoelectric signal to the control module; And / or, the monitoring device further includes a third electrode and a fourth electrode, which are spirally arranged along the extension direction of the cable core; the third electrode and the fourth electrode are both disposed on the outside of the second piezoelectric friction layer and are both electrically connected to the control module for transmitting the second piezoelectric signal to the control module.

4. The monitoring device according to claim 2, characterized in that, The first piezoelectric friction layer includes at least one first piezoelectric friction partition; the monitoring device further includes a fifth electrode and a sixth electrode, which are disposed at both ends of the first piezoelectric friction partition along the extension direction of the cable core, and are both electrically connected to the control module for transmitting the first piezoelectric signal generated by the first piezoelectric friction partition to the control module; And / or, the second piezoelectric friction layer includes at least one second piezoelectric friction partition; the monitoring device further includes a seventh electrode and an eighth electrode, the seventh electrode and the eighth electrode being disposed at both ends of the second piezoelectric friction partition along the extension direction of the cable core, and both being electrically connected to the control module for transmitting the second piezoelectric signal generated by the second piezoelectric friction partition to the control module.

5. The monitoring device according to claim 2, characterized in that, The cable core also includes a third cable core, which is disposed within the second cable core; The piezoelectric friction layer further includes a third piezoelectric friction layer; The third piezoelectric friction layer is wrapped around the third cable core and located inside the second cable core, and is electrically connected to the control module. It is used to generate a third piezoelectric signal when the third cable core is subjected to external force, and to send the third piezoelectric signal to the control module. The control module is also used to determine the stress condition of the cable based on the first piezoelectric signal, the second piezoelectric signal and the third piezoelectric signal.

6. The monitoring device according to claim 1, characterized in that, The monitoring device also includes an alarm module and a display module; The control module is also communicatively connected to the alarm module and is used to send an alarm signal to the alarm module when the piezoelectric signal exceeds the piezoelectric signal threshold. The alarm module is used to issue an alarm upon receiving the alarm signal; The control module is also communicatively connected to the display module and is used to send the status signal of the cable to the display module; The display module is used to display the status information of the cable according to the status signal.

7. A method for monitoring cable damage, characterized in that, The monitoring method, applied to the monitoring device as described in any one of claims 1-6, comprises: Obtain at least two piezoelectric signals output from at least two piezoelectric friction layers; The stress condition of the cable is determined based on at least two of the piezoelectric signals.

8. The monitoring method according to claim 7, characterized in that, The cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core. The at least two piezoelectric friction layers include a first piezoelectric friction layer and a second piezoelectric friction layer; At least two piezoelectric signals include a first voltage signal output by the first piezoelectric friction layer and a second piezoelectric signal output by the second piezoelectric friction layer; Determining the stress state of the cable based on at least two of the piezoelectric signals includes: The first piezoelectric signal is transformed in the frequency domain to obtain a first frequency domain signal, and the second piezoelectric signal is transformed in the frequency domain to obtain a second frequency domain signal; The degree of cable damage is determined based on the extent to which the first frequency domain signal deviates from the first preset frequency range, and / or the extent to which the second frequency domain signal deviates from the second preset frequency range.

9. The monitoring method according to claim 7, characterized in that, The cable core includes a first cable core and a second cable core, with the first cable core wrapped around the second cable core. The at least two piezoelectric friction layers include a first piezoelectric friction layer and a second piezoelectric friction layer; At least two piezoelectric signals include a first voltage signal output by the first piezoelectric friction layer and a second piezoelectric signal output by the second piezoelectric friction layer; Determining the stress state of the cable based on at least two of the piezoelectric signals includes: The stress position of the cable is determined based on the receiving order of the first piezoelectric signal and the second piezoelectric signal.

10. The monitoring method according to claim 7, characterized in that, After acquiring at least two piezoelectric signals output from at least two piezoelectric friction layers, the process also includes: At least two of the piezoelectric signals are filtered. At least two filtered piezoelectric signals are amplified to obtain at least two amplified signals; At least two of the amplified signals are subjected to noise reduction processing; The at least two amplified signals after noise reduction are normalized, and the at least two amplified signals are time-synchronized.

Images