Intelligent sensing core wire, sensing unit, geogrid and intelligent monitoring device

Abstract

The application discloses an intelligent sensing core wire, a sensing unit, a geogrid and an intelligent monitoring device, wherein the intelligent sensing core wire comprises a first resin base body, a ferrite arranged at the center of the first resin base body, and a conductive fiber bundle arranged in the resin base body and wound around the ferrite with a set twist. When the conductive fiber bundle passes through the current, an induced magnetic field is generated around the conductive fiber bundle and is concentrated on the ferrite. When the sensing core wire generates strain, the magnetic field is affected by the current and the change of the twist pitch of the fiber, the data measured under the same current change has a greater change, and thus the sensitivity is higher.

Description

Technical fields:

[0001] This invention relates to the field of automated testing technology, and more particularly to a processing method for an intelligent geogrid and the intelligent geogrid itself. Background technology:

[0002] Subgrade deformation is one of the main causes of reduced road smoothness and even pavement cracking. Geogrids have a good reinforcing effect on weak soil and can limit subgrade settlement.

[0003] The strain of geogrids is a crucial physical quantity reflecting the reliability of their reinforcement. Processing strain data allows us to derive important monitoring parameters such as the degree of damage to the geogrid, the amount of subgrade settlement, and the effectiveness of soil reinforcement. When the accuracy of the strain parameter is insufficient, errors accumulate in the calculations, potentially obscuring the true value.

[0004] Existing geogrids with monitoring capabilities typically involve bonding cables to the geogrid using adhesives such as resin, thereby measuring the geogrid's strain. However, when cables are connected to the geogrid via adhesives, the strain transfer coefficient means that the measured strain data often reflects the strain of the adhesive material, rather than directly measuring the true strain of the geogrid. In engineering applications, the strain transfer coefficient varies significantly with the strength, elastic modulus, and thickness of the geogrid, cables, and their adhesives, greatly reducing sensing accuracy. To address these issues, some researchers have proposed using 3D printing to embed cables within the geogrid for sensing. However, this method is difficult to manufacture, costly, and difficult to mass-produce, making it unsuitable for large-scale civil engineering projects.

[0005] Most importantly, the existing monitoring cables use sensing cores that calculate strain based on the measurement of current or voltage, which is not very sensitive. Summary of the Invention:

[0006] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing an intelligent sensing core wire, sensing unit, geogrid and intelligent monitoring device that improves monitoring sensitivity.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] This invention first provides an intelligent sensing core wire, comprising:

[0009] First resin matrix;

[0010] Ferrite disposed at the center of the first resin matrix;

[0011] Conductive fiber bundles disposed within the resin matrix are wound around the ferrite with a set twist. When an electric current passes through the conductive fiber bundles, an induced magnetic field is generated around them and concentrated on the ferrite.

[0012] This invention also provides a method for processing intelligent sensor core wires, comprising:

[0013] The conductive fiber bundles are pre-stretched.

[0014] An insulating thermoplastic elastomer is wrapped around the stretched conductive carbon fiber bundle;

[0015] A bundle of treated conductive carbon fibers is arranged around the ferrite core and coiled around the ferrite core with a certain twist.

[0016] An insulating thermoplastic elastomer is coated on the outside of the coiled wire harness to make a carbon fiber sensor;

[0017] The carbon fiber sensor is covered with a fiber sheath made of a blend of continuous basalt fiber and steel fiber.

[0018] An insulating thermoplastic elastomer is then coated onto the outside of the fiber sheath to form the sensing core wire.

[0019] The present invention also provides an intelligent sensing unit, comprising:

[0020] The aforementioned intelligent sensing core wire;

[0021] as well as

[0022] A magnetic sensor is used to acquire analog signals generated by changes in the magnetic field within the intelligent sensing core wire.

[0023] The present invention also provides an intelligent geogrid, comprising radial grid bars and latitudinal grid bars, characterized in that the aforementioned intelligent sensing core wire is provided in both the radial grid bars and the latitudinal grid bars.

[0024] The present invention also provides an intelligent monitoring device, comprising:

[0025] The signal generator emits low-frequency electrical pulse excitation signals;

[0026] The aforementioned intelligent sensing unit receives the low-frequency electrical pulse excitation signal emitted by the signal generator and generates an induced magnetic field around it.

[0027] The signal processing unit converts the analog signal of the magnetic field change generated by the intelligent sensing unit into a digital signal using a rectifier and a PCM pulse code modulation method.

[0028] Analysis unit: Receives the digital signal converted by the signal processing unit; calculates the distance of the signal source based on the time difference of signal arrival and the electrical signal transmission rate, thereby identifying the location where the deformation occurs; obtains the magnetic field change data measured by the magnetic sensor based on the signal content, obtains the twist change of the conductive fiber bundle, and thus identifies the corresponding strain value.

[0029] This invention also provides a method for processing an intelligent geogrid, comprising:

[0030] Conductive carbon fiber filaments are pre-stretched.

[0031] An insulating thermoplastic elastomer is wrapped around the stretched conductive carbon fiber filaments;

[0032] Twelve carbon fiber filaments, after being treated, are wound around the ferrite core with a certain twist.

[0033] An insulating thermoplastic elastomer is coated on the outside of the coiled wire harness to make a carbon fiber sensor;

[0034] The carbon fiber sensor is covered with a fiber sheath made of a blend of continuous basalt fiber and steel fiber.

[0035] An insulating thermoplastic elastomer is then coated onto the outside of the fiber sheath to form the sensing core wire;

[0036] A composite geogrid is formed by weaving grid strips composed of sensing core wires and fiber bundles.

[0037] During weaving, the insulating thermoplastic elastomer wrapped around the conductive carbon fiber bundles is heated, and after heating, it is cured and bonded to the basalt fiber grid strips.

[0038] This invention also provides a method for the layout and monitoring of intelligent geogrids, comprising:

[0039] During installation, the sensing core wire is stripped from the edge of the grid and connected to the magnetic sensor to form a sensing unit.

[0040] The sensing units are connected during deployment to form a quasi-distributed carbon fiber sensor array.

[0041] An excitation signal is transmitted to the sensing unit using an electrical pulse signal.

[0042] The magnetic field excited by the eddy current inside the sensing core wire and concentrated in the ferrite core is measured by a magnetic sensor.

[0043] The microprocessor inside the magnetic sensor converts the analog signal of the magnetic field change into a digital signal, which is then transmitted through a communication cable.

[0044] The method for pre-stretching conductive fibers is as follows:

[0045] Apply a certain amount of prestress to the conductive fiber filaments to eliminate the bending that occurs during the manufacturing of the conductive fiber bundle.

[0046] The conductive fiber filament is a carbon fiber filament.

[0047] The carbon fiber bundle is any one or more hybrid fibers selected from polyacrylonitrile-based carbon fiber, pitch-based carbon fiber, and viscose-based carbon fiber.

[0048] The ferrite is a soft magnetic ferrite, and is one of nickel-zinc ferrite, manganese ferrite, and zinc ferrite.

[0049] The carbon fiber bundles have a specification of 6k-48k.

[0050] The twist of the carbon fiber filaments coiled around the ferrite core is 12d-20d.

[0051] The thermoplastic elastomer is any one or a mixture of TPE (thermoplastic elastomer), TPEE (thermoplastic polyester elastomer), and TPU (thermoplastic polyurethane elastomer).

[0052] The fiber sheath is woven from a mixture of basalt fiber and steel fiber, with the steel fiber forming a mesh.

[0053] The sensing core wire is woven in two planes stacked on top of each other, forming intersecting two-dimensional, three-dimensional, four-dimensional or more two-dimensional or three-dimensional intelligent geogrid strips, with a grid spacing of 10-100mm and a grid thickness of 1-2mm.

[0054] The quasi-distributed carbon fiber sensor array consists of multiple identical sensing units connected in parallel with a bus.

[0055] The electrical pulse signal is transmitted by a low-frequency pulse generator.

[0056] The magnetic sensor is a fluxgate sensor, comprising a sensing module, a signal processing module, and a signal transmission module. The sensing module detects changes in the external magnetic field, the signal processing module converts the analog signal of the detected magnetic field change into a digital signal, and the signal transmission module converts the digital electrical signal into an optical signal for transmission via a communication cable.

[0057] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0058] (1) In the processing method of the present invention, the change of magnetic effect of current in the sensing core wire caused by deformation of the monitoring body is monitored by magnetic field induction. When the sensing core wire is strained, the magnetic field is affected by both the change of current and the change of fiber twist. The data measured under the same change of current has a larger change, and therefore has higher sensitivity.

[0059] (2) In the processing method of the present invention, the carbon fiber sensor is wrapped with a basalt fiber and steel fiber blended fiber sheath, which not only ensures the deformation capability of the sensor, but also shields the influence of the external magnetic field on the sensor, thereby improving the sensing accuracy.

[0060] (3) In the processing method of the present invention, the conductive fiber bundles after pretensioning are pre-coated with thermoplastic elastomer to avoid the problems of poor bonding reliability and easy detachment of traditional external sensors.

[0061] (4) The carbon fiber sensing core wire used in this invention has the advantages of being lightweight, high-strength, durable, corrosion-resistant, wear-resistant, strong deformation ability, and high monitoring accuracy.

[0062] (5) The composite geogrid woven by the present invention not only has the function of reinforcement, but also has the ability to sense, and can be widely used as an automated deformation monitoring device in the fields of deformation monitoring of transportation infrastructure such as highways, bridges, and airport runways in my country.

[0063] (6) The present invention uses thermoplastic elastomers and other materials as coating materials. After curing, the product has excellent flexibility, which is convenient for subsequent processes such as rolling, storage, transportation and construction.

[0064] (7) Traditional carbon fiber sensor deployment methods often employ continuous deployment, which can only reflect the average deformation of a certain road section. The intelligent monitoring device provided by this invention connects multiple separately deployed carbon fiber sensors together through a parallel circuit, enabling multi-point separate monitoring in the monitoring area, thereby improving the spatial resolution of the intelligent geogrid based on carbon fiber sensors.

[0065] (8) The intelligent monitoring device of this invention adopts electrical pulse time-domain reflectometry (OTDR) technology. This method calculates the signal transmission distance by recording the time difference between the signals received by the signal generator and the analysis unit, thereby achieving signal source localization. This solves the problem of monitoring signal acquisition and sensor localization for large-scale carbon fiber sensor arrays.

[0066] (9) The present invention has a wide range of applications as a smart geogrid weft strip material, and can be composite woven with a variety of common geogrid strip materials such as glass fiber and basalt fiber. Attached image description:

[0067] Figure 1 This is a schematic diagram of the cross-section of a carbon fiber smart core.

[0068] Figure 2 This is a schematic diagram of the intersection of intelligent geogrid strips.

[0069] Figure 3 This is a schematic diagram of the structure and layout of a two-dimensional bidirectional grid.

[0070] Figure 4 This is a structural diagram of a two-dimensional bidirectional grid.

[0071] The image shows: 1. Thermoplastic elastomer; 2. Carbon fiber bundle; 3. Basalt steel fiber blended fiber sheath; 4. Ferrite core; 5. Basalt grid fiber bundle; 6. Emulsified bitumen; 7. Sensing core wire; 8. Electrical pulse transmitter / signal receiver; 9. Analyzer; 10. Magnetic sensor; 11. Communication cable; 12. Basalt fiber grid strip. Detailed implementation method:

[0072] To provide a clearer understanding of the technical features, objectives, and effects of this invention, the invention is further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading this invention, any modifications of this invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

[0073] Example 1

[0074] This embodiment provides an intelligent sensing core wire, such as Figure 1 As shown, it includes:

[0075] First resin matrix;

[0076] Ferrite core 4 is disposed at the center of the first resin matrix;

[0077] Conductive fiber bundles 2 are disposed within a resin matrix and are wound around a ferrite core 4 with a set twist. When an electric current passes through the conductive fiber bundles, an induced magnetic field is generated around them and concentrated on the ferrite core 4.

[0078] In one embodiment, a fiber sheath 3 is wrapped around a first resin matrix; a second resin matrix is ​​disposed outside the fiber sheath.

[0079] In one embodiment, both the first resin matrix and the second resin matrix are thermoplastic elastomers 1.

[0080] In one embodiment, the ferrite core 4 is a soft magnetic ferrite, which is one of nickel-zinc ferrite, manganese ferrite, and zinc ferrite.

[0081] In one embodiment, the conductive fiber bundle 2 is a carbon fiber bundle; the carbon fiber bundle specification is 6k-48k, where k is the number of single filaments in the carbon fiber bundle, and 1k = 1000 filaments.

[0082] In one embodiment, the twist of the conductive fiber bundle coiled around the ferrite core is 12d-20d, where d is the diameter of the conductive fiber bundle.

[0083] Example 2

[0084] This embodiment provides a method for processing a smart sensor core wire, used for processing the smart sensor core wire provided in Embodiment 1. The method includes:

[0085] The conductive fiber bundle 2 is pre-stretched.

[0086] An insulating thermoplastic elastomer is wrapped around the stretched conductive carbon fiber bundle 2;

[0087] A ring of treated conductive carbon fiber bundles 2 is arranged outside the ferrite core 4 and coiled around the ferrite core 4 with a certain twist.

[0088] An insulating thermoplastic elastomer 1 is coated on the outside of the coiled wire harness to form a carbon fiber sensor;

[0089] The carbon fiber sensor is covered with a fiber sheath made of a blend of continuous basalt fiber and steel fiber 3;

[0090] An insulating thermoplastic elastomer is then coated onto the outside of the fiber sheath to form the sensing core wire.

[0091] Example 3

[0092] This embodiment provides an intelligent sensing unit, including:

[0093] The smart sensing core wire provided in Example 1;

[0094] as well as

[0095] The magnetic sensor 10 is used to acquire analog signals generated by changes in the magnetic field within the intelligent sensing core wire.

[0096] Example 4

[0097] A smart geogrid includes radial grid bars and latitudinal grid bars, and the smart sensing core wire provided in Example 1 is provided in both the radial grid bars and the latitudinal grid bars.

[0098] A method for processing an intelligent geogrid, comprising:

[0099] Conductive carbon fiber filaments are pre-stretched.

[0100] An insulating thermoplastic elastomer is wrapped around the stretched conductive carbon fiber filaments. Twelve treated carbon fiber filaments are coiled around a ferrite core with a certain twist. An insulating thermoplastic elastomer is then coated on the coiled wire bundle to make a carbon fiber sensor.

[0101] The carbon fiber sensor is covered with a fiber sheath made of a blend of continuous basalt fiber and steel fiber; an insulating thermoplastic elastomer is then coated on the fiber sheath to form the sensing core wire.

[0102] The sensing core wires are woven into a composite geogrid as part of the geogrid strips. The sensing core wires can be used as part of either the warp or weft geogrid strips of the composite geogrid, or they can be used as part of both warp and weft geogrid strips simultaneously. In this example, they are used as part of the weft geogrid strips.

[0103] The structure of the sensing core wire is shown in Figure 1 It consists of thermoplastic elastomer 1 and pre-stretched straight carbon fiber bundles 2. As part of the latitudinal grid strip, it is woven together with the latitudinal basalt fiber grid strip and then distributed perpendicularly to the warp basalt fiber grid strip in two stacked planes. See [reference needed]. Figure 2 A two-dimensional biaxial grid product with stable node bonding and insulating flexibility was obtained. Figure 4 ).

[0104] The cross-sectional shape of the sensing core wire can be elliptical, circular, or any other geometric shape, preferably rectangular.

[0105] The cross-sectional width of the sensing core wire is 5-10mm; the thickness is 3-5mm.

[0106] The sensing core wires in the cross-section of the grid strip can be uniformly distributed as a whole, uniformly bundled, unevenly bundled, uniformly bundled, or unevenly bundled.

[0107] The sensing core wire is suitable for two-dimensional or three-dimensional intelligent geogrid strips with a braided form that is located in two planes that are stacked on top of each other or can be interlaced. The grid spacing is 10-100mm and the grid thickness is 1-2mm.

[0108] Example 5

[0109] This embodiment provides an intelligent monitoring device, including:

[0110] The signal generator emits low-frequency electrical pulse excitation signals;

[0111] The intelligent sensing unit provided in Example 3 receives the low-frequency electrical pulse excitation signal emitted by the signal generator and generates an induced magnetic field around it.

[0112] The signal processing unit converts the analog signal of the magnetic field change generated by the intelligent sensing unit into a digital signal using a rectifier and a PCM pulse code modulation method.

[0113] Analysis Unit: Receives the digital signal converted by the signal processing unit; calculates the distance to the signal source based on the signal arrival time difference and the electrical signal transmission rate, thereby identifying the location of deformation; obtains the magnetic field change data measured by the magnetic sensor based on the signal content, obtains the twist change of the conductive fiber bundle, and thus identifies the corresponding strain value.

[0114] The principle by which intelligent monitoring devices achieve monitoring is:

[0115] When the sensing core wire experiences axial strain, the carbon fiber twist increases, while the internal stress of the fiber increases and the cross-section decreases, satisfying the following equation:

[0116]

[0117] Where, ε x The axial strain of the sensing core wire is given by ΔD, where ΔD represents the change in twist pitch, D represents the twist pitch, and ε represents the change in twist pitch. cy denoted as tangential strain of the carbon fiber filament cross section, μ as Poisson's ratio of the carbon fiber filament, and d0 as the distance from the center of the carbon fiber filament to the sensing core wire.

[0118] At the same time, the internal stress of the fiber increases while the cross-section decreases, thus increasing the resistance R and decreasing the current I, satisfying the following equation:

[0119]

[0120]

[0121]

[0122] Where R0 is the resistance of a single carbon fiber bundle, ρ is the resistivity of the carbon fiber material, L0 is the length of the carbon fiber filament, S is the area of ​​a single carbon fiber filament, L is the length of the sensing core wire, and r is the radius of the carbon fiber filament. 12 U is the resistance of all carbon fiber filaments within a single sensing core wire, U is the pulse voltage of the electric pulse transmitter, and I is the pulse current.

[0123] Due to changes in current, the magnetic field strength within the ferrite core changes and is detected by a magnetic sensor, satisfying the following equation:

[0124]

[0125] Where B represents the strength of the magnetic field to be measured, in Tesla (T), and μ0 represents the free permeability, μ r The relative permeability of the ferrite core is represented by I, which represents the current in amperes (A); and D represents the twist pitch in meters (m).

[0126] The voltage of the magnetic sensor probe circuit changes, generating an analog signal with a voltage output.

[0127] The analog signal is fed into the microprocessor, converted into a digital signal by the PCM pulse code modulation method through the filtering element, and then output to the analysis unit.

[0128] The analysis unit receives digital signals, calculates the distance to the signal source based on the signal transmission speed and the signal time difference, and determines its location; it obtains the magnetic field change data measured by the magnetic sensor based on the signal content, and calculates the twist change of the conductive fiber according to equations (1-1) to (1-5), thereby identifying the location of deformation and the corresponding strain value.

[0129] Example 6:

[0130] A method for the placement and monitoring of intelligent geogrids, comprising:

[0131] Strip the sensor core wire from the edge of the grille and connect it to the power supply bus.

[0132] Connect the magnetic sensor to the power supply bus and align the measurement direction of the magnetic sensor with the central axis of the sensing core wire to form a sensing unit.

[0133] Multiple sensing units are connected in parallel to the power supply bus, and the signal transmission module of the magnetic sensor is connected to the communication cable to form a quasi-distributed carbon fiber sensor array.

[0134] An electrical pulse signal transmitter is used to transmit an electrical pulse excitation signal to the sensing unit.

[0135] When the sensing core wire generates axial strain, the twist pitch of the carbon fiber increases, and at the same time, the internal stress of the fiber increases while the cross-section decreases, satisfying the following formula.

[0136]

[0137] Where ε x To sense the axial strain of the core wire, ε cy denoted as tangential strain of the carbon fiber filament cross section, μ as Poisson's ratio of the carbon fiber filament, and d0 as the distance from the center of the carbon fiber filament to the sensing core wire.

[0138] At the same time, the internal stress of the fiber increases while the cross-section decreases, thus increasing the resistance R and decreasing the current I, satisfying the following equation.

[0139]

[0140]

[0141]

[0142] Where R0 is the resistance of a single carbon fiber bundle, ρ is the resistivity of the carbon fiber material, L0 is the length of the carbon fiber filament, S is the area of ​​a single carbon fiber filament, L is the length of the sensing core wire, and r is the radius of the carbon fiber filament. 12 U is the resistance of all carbon fiber filaments within a single sensing core wire, U is the pulse voltage of the electric pulse transmitter, and I is the pulse current.

[0143] Due to changes in current, the magnetic field strength within the ferrite core changes and is detected by a magnetic sensor, satisfying the following equation:

[0144]

[0145] Where B represents the strength of the magnetic field to be measured, in Tesla (T), and μ0 represents the free permeability, μ r The values ​​represent the relative permeability of the ferrite core; I represents the current, measured in amperes (A); and D represents the twist pitch, measured in meters (m).

[0146] The voltage of the magnetic sensor probe circuit changes, generating an analog signal with a voltage output.

[0147] The analog signal is fed into the microprocessor, converted into a digital signal by the PCM pulse code modulation method through the filtering element, and then output to the analysis unit.

[0148] The analysis unit receives digital signals, calculates the distance to the signal source based on the signal transmission speed and the signal time difference, and determines its location; it obtains the magnetic field change data measured by the magnetic sensor based on the signal content, and calculates the twist change of the conductive fiber according to equations (1-1) to (1-5), thereby identifying the location of deformation and the corresponding strain value.

[0149] Compared to traditional methods that calculate strain by measuring current or voltage, equations (1-1)-(1-5) show that when strain occurs in the sensing core wire, the current decreases, the change in twist pitch increases, and the magnetic field weakens accordingly. Here, magnetic flux B is a higher-order quantity of current I. For the same strain value, the response to changes in magnetic flux is greater than that to changes in current; therefore, this method has higher sensitivity.

Claims

1. An intelligent monitoring device, characterized in that, include: The signal generator emits low-frequency electrical pulse excitation signals; Intelligent sensing unit; It receives the low-frequency electrical pulse excitation signal emitted by the signal generator and generates an induced magnetic field around it; The signal processing unit converts the analog signal of the magnetic field change generated by the intelligent sensing unit into a digital signal using a rectifier and a PCM pulse code modulation method. Analysis unit: Receives the digital signal converted by the signal processing unit; calculates the distance to the signal source based on the time difference of signal arrival and the electrical signal transmission rate, thereby identifying the location where the deformation occurred; Based on the signal content, the magnetic field change data measured by the magnetic sensor is obtained, the twist pitch change of the conductive fiber bundle is obtained, and the corresponding strain value is identified. The intelligent sensing unit includes an intelligent sensing core wire and a magnetic sensor. The magnetic sensor is used to acquire analog signals generated by changes in the magnetic field within the intelligent sensing core wire. The intelligent sensing core wire includes: First resin matrix; Ferrite disposed at the center of the first resin matrix; Conductive fiber bundles disposed within the resin matrix are wound around the ferrite with a set twist. When an electric current passes through the conductive fiber bundles, an induced magnetic field is generated around them and concentrated on the ferrite.

2. The intelligent monitoring device according to claim 1, characterized in that, A low-frequency electrical pulse generator is used to generate 1kHz, 1kV electrical pulses to apply current excitation to the sensor unit. The steps for obtaining magnetic field change data measured by the magnetic sensor based on the signal content, obtaining the twist change of the conductive fiber bundle, and thus identifying the corresponding strain value include: Based on the signal content, the magnetic field change data measured by the magnetic sensor is obtained, and the twist pitch change of the conductive fiber bundle is obtained: in, Indicates the change in twist pitch; Indicates the strength of the magnetic field to be measured. Represents the permeability of free space. The relative permeability of the ferrite core is represented by I, and the electric current is represented by I. Indicates the twist pitch; Based on the change in twist pitch of the obtained conductive fiber bundle, the corresponding strain value is identified: in, This represents the axial strain of the sensing core wire.

3. The intelligent monitoring device according to claim 1, characterized in that, A fiber sheath is coated on the first resin matrix; a second resin matrix is ​​disposed outside the fiber sheath.

4. The intelligent monitoring device according to claim 1, characterized in that, The ferrite is a soft magnetic ferrite.

5. The intelligent monitoring device according to claim 1, characterized in that, The ferrite is one of nickel-zinc ferrite, manganese ferrite, or zinc ferrite.

6. The intelligent monitoring device according to claim 1, characterized in that, The conductive fiber bundle is a carbon fiber bundle; the carbon fiber bundle specification is 6k-48k, where k is the number of single filaments in the carbon fiber bundle, and 1k = 1000 filaments.

7. The intelligent monitoring device according to claim 1, characterized in that, The twist of the conductive fiber bundle coiled around the ferrite core is 12d-20d, where d is the diameter of the conductive fiber bundle.

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