A Method and System for Transmitting Micro-Vibration Signals Based on Fiber Optic Sensing Eddy Current Detection

Abstract

This application provides a method and system for transmitting micro-vibration signals in eddy current detection based on fiber optic sensing. The method involves first creating a periodic pressure disturbance in a predetermined area; then generating a micro-vibration signal based on the periodic pressure disturbance; next, converting the micro-vibration signal into a backscattered light signal; then demodulating the phase of the backscattered light signal to extract the phase change, making the phase change correspond to the dynamic changes of the eddy current field; subsequently, based on the correlation between the phase change and the flight parameters of a UAV, the phase change is encoded into a digital eddy current feature sequence; finally, the digital eddy current feature sequence is transmitted to a remote monitoring platform via a fiber optic communication link to complete the transmission of the eddy current detection micro-vibration signal. The technical solution provided in this application improves the targeting and reliability of monitoring, and also achieves high-sensitivity detection, accurate feature extraction, and reliable remote transmission of micro-vibration signals in eddy current fields.

Description

Technical Field

[0001] This application relates to the field of signal transmission technology, and in particular to a method and system for transmitting micro-vibration signals based on eddy current sensing using fiber optic sensing. Background Technology

[0002] In areas such as perimeter security of critical infrastructure, effective monitoring of low-altitude drone intrusions is an important technical requirement. Such scenarios require monitoring systems to have wide coverage, high sensitivity, and strong anti-interference capabilities, and to effectively sense the subtle changes in the physical field generated by drones during flight and transmit relevant information to a remote monitoring center in real time for analysis and early warning.

[0003] In the existing technology, a targeted solution is to use a ground-based vibration sensor array for monitoring. By deploying multiple independent vibration sensing nodes on the ground, the sound waves or vibration signals generated by the rotor of the UAV during takeoff, landing or low-altitude flight are collected. Each node transmits the collected data to the processing center via a wireless network for fusion analysis to determine the position and status of the UAV.

[0004] However, the existing solutions mentioned above have obvious drawbacks. First, the vibration sensor array is susceptible to environmental noise interference and it is difficult to effectively separate the micro-vibration characteristics of the eddy current field unique to UAVs from the complex ground vibration background, resulting in insufficient monitoring sensitivity and a high false alarm rate. Second, the dispersed wireless sensing nodes face challenges in data synchronization and transmission reliability, making it difficult to guarantee the integrity and real-time performance of monitoring data, and the system deployment and maintenance costs are high. Summary of the Invention

[0005] This application provides a method and system for transmitting micro-vibration signals based on fiber optic sensing for eddy current detection, which solves the problems of low monitoring sensitivity, high false alarm rate, difficulty in ensuring data synchronization and transmission reliability, and high system deployment and maintenance costs caused by large environmental noise interference in the prior art.

[0006] In a first aspect, this application provides a method for transmitting micro-vibration signals for eddy current detection based on fiber optic sensing, comprising:

[0007] Controlling a drone to fly within a preset area, causing the vortex field generated by the drone's rotor rotation to create periodic pressure disturbances on the preset area, wherein the preset area is an area where sensing optical fibers are buried on the ground surface;

[0008] Based on the periodic pressure disturbance of the preset area by the eddy current field, a micro-vibration signal is generated, and the micro-vibration signal contains eddy current characteristic information.

[0009] Based on the sensing fiber, the micro-vibration signal is converted into a backscattered light signal;

[0010] The backscattered light signal is phase demodulated, and the phase change is extracted. The phase change corresponds to the dynamic change of the eddy current field.

[0011] Based on the correlation between the phase change and the UAV flight parameters, the phase change is encoded into a digital eddy current feature sequence;

[0012] The digital eddy current feature sequence is transmitted to a remote monitoring platform via an optical fiber communication link to complete the transmission of micro-vibration signals for eddy current detection.

[0013] Optionally, the drone is controlled to fly within a preset area, such that the vortex field generated by the drone's rotor rotation creates periodic pressure disturbances on the preset area. The preset area is a region where sensing optical fibers are buried on the ground surface, including:

[0014] The drone is controlled to fly along a preset flight path at a preset cruising altitude. By continuously rotating the drone's rotor, air is pushed downward at the preset cruising altitude, thereby generating a dynamic vortex field below the drone's rotor.

[0015] The dynamic vortex field impacts the surface of the preset area, causing the air pressure on the surface to change periodically with the rotation frequency of the UAV's rotor and the flight speed of the UAV, thereby generating periodic pressure disturbances.

[0016] Optionally, based on the periodic pressure disturbance of the preset region by the eddy current field, a micro-vibration signal is generated, the micro-vibration signal containing eddy current characteristic information, including:

[0017] The periodic pressure disturbance is applied to the surface of the preset area to be converted into a periodic mechanical force on the surface medium.

[0018] The periodic mechanical force induces elastic deformation in the surface medium that is synchronized with the pressure change of the eddy current field, wherein the elastic deformation propagates in the surface medium in a predetermined direction in the form of stress waves.

[0019] Stress waves are applied to the sensing optical fiber buried in the surface medium, causing the sensing optical fiber to generate corresponding mechanical vibrations according to the periodicity of the stress waves.

[0020] The mechanical vibrations corresponding to the sensing optical fiber are recorded as micro-vibration signals.

[0021] Optionally, based on the sensing fiber, the micro-vibration signal is converted into a backscattered light signal, including:

[0022] Injecting continuous light waves into the sensing optical fiber, which serves as a distributed sensing medium;

[0023] The micro-vibration signal causes local deformation of the sensing optical fiber, so that the optical phase of the continuous light wave is directly modulated at the deformation position when the continuous light wave is transmitted in the sensing optical fiber.

[0024] Based on the change in optical phase, the mechanical vibration of the micro-vibration signal is converted into the continuous light wave to form a phase-modulated light wave;

[0025] The backscattered light generated inside the sensing fiber by the phase-modulated light wave is collected to obtain the backscattered light signal.

[0026] Optionally, the backscattered light signal is phase demodulated to extract the phase change, which corresponds to the dynamic change of the eddy current field, including:

[0027] The backscattered light signal is mixed with a preset reference light signal to generate an interference light signal;

[0028] The intensity change of the interference light signal is detected, wherein the intensity change corresponds to the phase difference between the backscattered light signal and the reference light signal;

[0029] The intensity change of the interference optical signal is converted into an electrical signal;

[0030] Separate the periodic fluctuation component caused by the micro-vibration signal from the electrical signal;

[0031] Based on the correspondence between the light intensity and phase difference of the interference light signal, the sequence of phase change of the backscattered light signal over time is reconstructed from the periodic fluctuation component, and the sequence of phase change over time is used as the phase change quantity.

[0032] Optionally, based on the correlation between the phase change and the UAV flight parameters, the phase change is encoded into a digital eddy current feature sequence, including:

[0033] The phase change is divided into multiple consecutive time segments in chronological order;

[0034] Match a corresponding UAV flight parameter set to each time segment, the flight parameter set including the UAV's flight speed and rotor speed within the time segment;

[0035] The average phase change amplitude and dominant phase change frequency within each time segment are bound to the matched flight parameter set to form a data unit;

[0036] According to the time sequence of the time segment, the amplitude, frequency and flight parameter group in each data unit are converted into digital codes in a predetermined format;

[0037] The digital codes corresponding to the time segments are combined in chronological order to obtain the digital eddy current feature sequence.

[0038] Optionally, the digital eddy current feature sequence is transmitted to a remote monitoring platform via an optical fiber communication link to complete the transmission of the eddy current detection micro-vibration signal, including:

[0039] The digital eddy current feature sequence is encapsulated into continuous data packets according to a preset communication protocol;

[0040] Continuous data packets are modulated onto an optical carrier to generate an optical signal;

[0041] The optical signal is injected into the optical fiber communication link used for transmission, and the optical signal is transmitted along the optical fiber towards the remote monitoring platform.

[0042] The remote monitoring platform receives the optical signal and demodulates it to recover the continuous data packets.

[0043] The continuous data packets are parsed according to the preset communication protocol to recover the digital eddy current feature sequence.

[0044] Secondly, this application provides a fiber optic sensing-based eddy current detection micro-vibration signal transmission system, comprising:

[0045] The control module is used to control the drone to fly within a preset area, so that the vortex field generated by the rotation of the drone's rotor creates periodic pressure disturbances on the preset area, wherein the preset area is an area where sensing optical fibers are buried on the ground surface.

[0046] The generation module is used to generate micro-vibration signals based on the periodic pressure disturbance of the preset area by the eddy field, wherein the micro-vibration signals contain eddy characteristic information.

[0047] A conversion module is used to convert the micro-vibration signal into a backscattered light signal based on the sensing fiber;

[0048] The extraction module is used to perform phase demodulation on the backscattered light signal and extract the phase change, which corresponds to the dynamic change of the eddy current field.

[0049] The encoding module is used to encode the phase change amount into a digital eddy current feature sequence based on the correlation between the phase change amount and the UAV flight parameters;

[0050] The transmission module is used to transmit the digital eddy current feature sequence to a remote monitoring platform via an optical fiber communication link to complete the transmission of eddy current detection micro-vibration signals.

[0051] Thirdly, this application provides a computing device, including a processing component and a storage component; the storage component stores one or more computer instructions; the one or more computer instructions are invoked and executed by the processing component to implement the eddy current detection micro-vibration signal transmission method based on fiber optic sensing as described in the first aspect above.

[0052] Fourthly, this application provides a computer storage medium storing a computer program, which, when executed by a computer, implements a method for transmitting micro-vibration signals based on eddy current sensing as described in the first aspect.

[0053] This application utilizes the effect of the eddy current field generated by the rotor of a UAV on the buried sensing optical fiber to convert the dynamic information of the aircraft into micro-vibration signals on the ground surface. The optical fiber itself completes the conversion and transmission from mechanical vibration to optical signal and then to digital feature sequence. It effectively utilizes the distributed sensing characteristics of optical fiber to achieve wide-area and high-sensitivity detection of changes in specific physical fields, forming a complete closed technical path from physical disturbance perception to remote information transmission, which significantly improves the targeting and reliability of monitoring.

[0054] Furthermore, by directly transmitting the encoded digital eddy current feature sequence via an optical fiber communication link, the integrity and anti-interference capability of the monitoring data during transmission are ensured. This transmission process utilizes existing optical fiber links, avoiding the stability problems common in wireless transmission, and ensuring the continuity and accuracy of data transmission from the detection end to the monitoring platform end, providing a reliable data foundation for subsequent analysis.

[0055] These or other aspects of this application will become more apparent in the following description of the embodiments. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A flowchart of a method for transmitting micro-vibration signals based on eddy current sensing provided in this application is shown.

[0058] Figure 2 A schematic diagram of the structure of a fiber optic sensing-based eddy current detection micro-vibration signal transmission system provided in this application is shown.

[0059] Figure 3 A schematic diagram of the structure of a computing device provided in this application is shown. Detailed Implementation

[0060] To enable those skilled in the art to better understand the present application, the technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0061] In some of the processes described in the specification, claims, and accompanying drawings of this application, multiple operations appearing in a specific order are included. However, it should be clearly understood that these operations may not be executed in the order they appear herein, or may be executed in parallel. The operation numbers, such as 101, 102, etc., are merely used to distinguish different operations and do not themselves represent any execution order. Furthermore, these processes may include more or fewer operations, and these operations may be executed sequentially or in parallel. It should be noted that the descriptions such as "first," "second," etc., in this document are used to distinguish different messages, devices, modules, etc., and do not represent a sequential order, nor do they limit "first" and "second" to different types.

[0062] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0063] Figure 1 This application provides a flowchart of a method for transmitting micro-vibration signals based on fiber optic sensing for eddy current detection, as shown below. Figure 1 As shown, the method includes:

[0064] Step 101: Control the drone to fly within a preset area, so that the vortex field generated by the rotation of the drone's rotor creates periodic pressure disturbances on the preset area, wherein the preset area is an area where sensing optical fibers are buried on the ground.

[0065] Optionally, step 101 may specifically include the following steps:

[0066] Step 1011: Control the UAV to fly along a preset flight path at a preset cruising altitude. By continuously rotating the UAV's rotor, the air is pushed downward at the preset cruising altitude, so as to generate a dynamic vortex field under the UAV's rotor.

[0067] Step 1012: The dynamic vortex field impacts the surface of the preset area, causing the air pressure on the surface to change periodically with the rotation frequency of the UAV's rotor and the flight speed of the UAV, thereby generating periodic pressure disturbances.

[0068] In the above scheme, the preset area refers to the pre-delineated surface monitoring range, which is used to limit the effective space of the UAV vortex field and the boundary is determined by geographical survey.

[0069] A rotor is a rotating blade assembly on top of a drone that pushes air to create a downward airflow and is driven by a motor to achieve rotation.

[0070] A vortex field refers to the region of rotating airflow formed when a rotor rotates, which is used to transfer mechanical energy to the ground surface and is formed naturally through aerodynamic processes.

[0071] Periodic pressure disturbances refer to regular pressure changes on the Earth's surface caused by airflow, which are used to excite micro-vibration signals and are monitored by pressure sensors.

[0072] The surface refers to the soil medium layer covering the sensing optical fiber, which is used to transmit vibrational energy and is formed through natural geological structures;

[0073] The preset cruising altitude refers to the fixed flight altitude of the UAV relative to the ground surface, which is used to control the intensity of the eddy field and is obtained by setting flight parameters;

[0074] The preset flight path refers to the planned route for the UAV's flight, which is used to ensure that the vortex field covers the target area. It is obtained by setting waypoint coordinates.

[0075] Downward motion refers to the vertical displacement of air caused by the rotor, which is used to generate impact force and is produced through fluid dynamics.

[0076] Dynamic vortex field refers to the airflow region that changes with the movement of the UAV, used to continuously generate pressure disturbances, and is formed by airflow movement during flight;

[0077] Air pressure refers to the force exerted by airflow on a unit area of ​​the Earth's surface. It is used to quantify the intensity of disturbances and is measured by pressure sensing devices.

[0078] Rotation frequency refers to the number of times the rotor rotates per unit time. It is used to determine the frequency of pressure changes and is obtained by controlling the motor speed.

[0079] Flight speed refers to the rate at which the UAV moves horizontally, and is used to influence the vortex field morphology. It is obtained by adjusting the flight control system.

[0080] Periodic fluctuations refer to the phenomenon of air pressure fluctuating regularly over time, which is detected by continuous monitoring of pressure values.

[0081] In this scheme, firstly, the waypoint navigation algorithm of the flight control system generates UAV control commands based on the coordinate sequence of the preset flight path, enabling the UAV to maintain a fixed altitude flight along the planned path at the preset cruising altitude. Secondly, based on the principle of rotor aerodynamics, the motor speed is precisely adjusted by a PID controller, causing the rotor to rotate continuously at a set frequency, pushing the air to form a dynamic vortex field with a specific energy distribution. Then, according to the Navier-Stokes equations in fluid mechanics, when the dynamic vortex field interacts with the ground surface, the air kinetic energy is converted into ground pressure load through the pressure field transfer mechanism. Finally, combined with the kinematic model, the coupling relationship between flight speed and rotor speed is calculated in real time, and the action parameters of the vortex field are dynamically adjusted to make the ground air pressure exhibit a stable periodic strength variation pattern, forming a periodic pressure disturbance that conforms to the preset characteristics.

[0082] For example, after burying sensing optical fibers in a strip area with a length of 500 meters, the ground control station generates a flight path containing 20 waypoints through a waypoint planning algorithm; the UAV flight control system maintains a cruising altitude of 15 meters using a PID control algorithm based on the path coordinates, while adjusting the rotor to rotate at a speed of 1200 revolutions per minute; when the UAV flies at a speed of 8 meters per second, according to the computational fluid dynamics simulation results, the vortex field generated by the rotor forms a periodic pressure disturbance with a frequency of 20 Hz and an amplitude of 20 Pa on the ground surface, and this periodic pressure disturbance shows a regular distribution along the fiber optic direction.

[0083] This step achieves precise conversion of physical field energy through multi-algorithm collaborative control, waypoint navigation ensures spatial positioning accuracy, PID control guarantees motion stability, and fluid dynamics model guides parameter optimization, ultimately forming periodic pressure disturbances that meet the detection requirements, thus establishing ideal excitation conditions for subsequent signal detection.

[0084] Step 102: Based on the periodic pressure disturbance of the preset area by the eddy field, a micro-vibration signal is generated, and the micro-vibration signal contains eddy characteristic information.

[0085] Optionally, step 102 may specifically include the following steps:

[0086] Step 1021: Apply the periodic pressure disturbance to the surface of the preset area to convert it into a periodic mechanical force on the surface medium.

[0087] Step 1022: The periodic mechanical force induces elastic deformation in the surface medium that is synchronized with the pressure change of the eddy current field, wherein the elastic deformation propagates in the surface medium in a predetermined direction in the form of stress waves.

[0088] Step 1023: Apply the stress wave to the sensing optical fiber buried in the surface medium, so that the sensing optical fiber generates corresponding mechanical vibration according to the periodicity of the stress wave.

[0089] Step 1024: The mechanical vibration corresponding to the sensing optical fiber is recorded as a micro-vibration signal.

[0090] In the above scheme, the micro-vibration signal refers to the weak physical signal generated by mechanical vibration, which is used to carry the characteristic information of the eddy current field and is acquired by the vibration sensor;

[0091] Eddy flow characteristic information refers to the airflow field characteristic data contained in the vibration signal, which is used to identify the motion state of the UAV and is extracted through signal analysis.

[0092] The surface medium refers to the soil material layer covering the sensing optical fiber, which is used to transmit mechanical vibrations and whose composition is determined through geological exploration.

[0093] Periodic mechanical force refers to the thrust generated by regularly changing pressure on the earth's surface, which is used to induce soil vibration and is obtained through the pressure-force conversion relationship;

[0094] Pressure change refers to the phenomenon of air pressure fluctuating over time, which is used to drive the deformation of the medium and is monitored by a pressure sensor;

[0095] Elastic deformation refers to the recoverable deformation of an object under the action of external force. It is used to propagate vibrational energy and is generated through the mechanical properties of materials.

[0096] Stress wave form refers to the propagation mode of mechanical stress in a medium, used to transmit vibration signals, and is described by the wave equation;

[0097] The preset direction refers to the specific orientation of the vibration wave propagation, which is used to guide the sensing optical fiber and is determined by the direction of the optical fiber laying.

[0098] Mechanical vibration refers to the reciprocating motion of an object around its equilibrium position, used to generate physical signals and excited by mechanical action.

[0099] In this scheme, firstly, through a pressure transmission mechanism, periodic pressure disturbances are uniformly applied to a unit area of ​​the surface medium in the form of pressure, generating a corresponding periodic mechanical force based on the area of ​​application. Pressure sensors monitor the pressure value in real time, and combined with preset area parameters, the accurate mechanical force value is calculated. Secondly, based on the principle of elastic deformation of the medium, the periodic mechanical force causes reciprocating displacement of particles within the surface medium. This reciprocating displacement propagates as stress waves along the medium in a preset direction, following the propagation law of mechanical waves in continuous media. By monitoring the motion state of the medium particles, the propagation path of the stress waves can be tracked. Then, through solid-coupled energy transfer, when the stress wave propagates to the interface between the sensing fiber and the soil, the mechanical energy of the wave is completely transferred to the sensing fiber through the interface shear force. According to the wave transfer principle, the sensing fiber generates forced vibration with the same frequency as the wave under the action of the stress wave, and the vibration amplitude is proportional to the intensity of the stress wave. Finally, using vibration signal acquisition technology, the mechanical vibration is detected by an accelerometer installed on the sensing fiber. The accelerometer converts the vibration acceleration signal of the sensing fiber into a displacement signal through an integrator circuit, and then generates a digital micro-vibration signal through an analog-to-digital converter, completing the complete conversion process from physical vibration to electrical signal.

[0100] For example, following a specific embodiment of the previous solution, the periodic pressure disturbance generated by the drone flying above the sensing fiber acts on a specific location within the area where the sensing fiber is buried. When the periodic pressure disturbance acts on the ground surface at a specific frequency, according to the principle of mechanical transmission, a corresponding periodic mechanical force is generated in the soil layer below the pressure point. This periodic mechanical force causes the soil particles to undergo elastic deformation, and the deformation propagates along the direction of the sensing fiber in the form of stress waves. When the wave propagates to the sensing fiber at a burial depth of 0.3 meters, the fiber generates mechanical vibration at the same frequency, and the vibration sensor ultimately outputs a micro-vibration signal containing the characteristic parameters of the drone rotor.

[0101] This step achieves high-fidelity conversion from pressure disturbance to vibration signal through a complete physical transmission chain, establishes a reliable correspondence between aerodynamic effects and mechanical vibration signal, ensures the complete preservation of eddy current field characteristic information, and provides a high-quality data source for subsequent signal processing.

[0102] Step 103: Based on the sensing fiber, the micro-vibration signal is converted into a backscattered light signal.

[0103] Optionally, step 103 may specifically include the following steps:

[0104] Step 1031: Inject continuous light waves into the sensing optical fiber, which serves as the distributed sensing medium.

[0105] Step 1032: The micro-vibration signal causes local deformation of the sensing optical fiber, so that the optical phase of the continuous light wave is directly modulated at the deformation position when the continuous light wave is transmitted in the sensing optical fiber.

[0106] Step 1033: Based on the change in optical phase, the mechanical vibration of the micro-vibration signal is converted into the continuous light wave to form a phase-modulated light wave;

[0107] Step 1034: Collect the backscattered light generated inside the sensing fiber by the phase-modulated light wave to obtain the backscattered light signal.

[0108] In the above scheme, the distributed sensing medium refers to an optical fiber carrier with continuous sensing capability, which is used to realize spatially distributed signal detection and is obtained through optical fiber laying process.

[0109] Backscattered light signal refers to the scattered light signal that propagates in the opposite direction to the light source. It is used to carry vibration information and is collected by a photodetector.

[0110] Continuous light waves refer to laser beams with stable intensity, used to provide a detection light source, and are generated by laser emission;

[0111] Optical phase refers to the periodic position of a light wave during its propagation. It is used to characterize the wave state and is obtained through interferometry.

[0112] The deformation location refers to the specific section of the optical fiber where mechanical deformation occurs. It is used to locate the vibration point and is determined by optical time-domain reflectometry.

[0113] Phase-modulated light waves refer to light wave signals whose phase carries information, used to transmit vibration data, and are generated through phase modulation technology.

[0114] Backscattered light refers to backscattered light generated due to inhomogeneity of the medium, which is used for signal extraction and is formed by Rayleigh scattering.

[0115] In this scheme, a stable continuous light wave is first generated by a laser emission system. A semiconductor laser is used as the light source, and a precision temperature control system is used to keep the laser wavelength stable. The laser is injected into the end face of the sensing fiber using an optical fiber coupler, and the incident light power is kept below the nonlinear threshold of the fiber by adjusting the optical power amplifier. Secondly, when the micro-vibration signal is transmitted to the sensing fiber, according to the principle of photoelasticity, the mechanical strain of the sensing fiber at the deformation position will cause a linear change in the refractive index. By monitoring the transmission state of the light wave in the fiber in real time, the change in the phase of the light wave is detected by interferometry.

[0116] Then, phase modulation technology is used to convert the phase change caused by mechanical vibration into modulation of the optical wave phase. When the phase-modulated light wave carrying vibration information is transmitted in the sensing fiber, each tiny scattering point in the sensing fiber will generate backscattered light using the Rayleigh scattering principle. These backscattered lights carry phase modulation information during their return transmission. Finally, the returned backscattered light signal is directly collected by a high-sensitivity photodetector, and the light intensity signal is converted into an electrical signal. The electrical signal is amplified and filtered using a signal conditioning circuit, and the analog signal is converted into a digital signal by an analog-to-digital converter. Finally, the backscattered light signal containing vibration information is obtained. The entire process reflects the original vibration information by measuring the change in the intensity of the backscattered light.

[0117] For example, following a specific embodiment of the previous scheme, the output micro-vibration signal is obtained. When the micro-vibration signal is transmitted to the sensing optical fiber buried underground, the optical fiber undergoes periodic deformation due to vibration. A distributed optical fiber sensing system is used to inject a continuous light wave with a wavelength of 1550 nanometers into the sensing optical fiber. In the vibration zone, the deformation of the sensing optical fiber changes the transmission phase of the laser through the photoelastic effect, converting the mechanical vibration information into an optical phase change. When the light wave carrying the phase information is transmitted in the optical fiber, it generates backscattered Rayleigh light. This scattered light returns along the original path to the beginning of the optical fiber and is finally received by the photoelectric detection system and converted into an electrical signal containing vibration characteristics, i.e., a backscattered light signal.

[0118] This step achieves high-fidelity conversion of mechanical vibration into optical signals through a complete photoelectric conversion chain, and realizes spatial positioning detection of vibration information by utilizing the characteristics of distributed optical fiber sensing, forming a passive transmission path from physical vibration to optical signals, thereby improving the reliability and anti-interference capability of signal detection.

[0119] Step 104: Perform phase demodulation on the backscattered light signal and extract the phase change amount, which corresponds to the dynamic change of the eddy current field.

[0120] Optionally, step 104 may specifically include the following steps:

[0121] Step 1041: Mix the backscattered light signal with a preset reference light signal to generate an interference light signal;

[0122] Step 1042: Detect the intensity change of the interference light signal, wherein the intensity change corresponds to the phase difference between the backscattered light signal and the reference light signal;

[0123] Step 1043: Convert the intensity change of the interference optical signal into an electrical signal;

[0124] Step 1044: Separate the periodic fluctuation component caused by the micro-vibration signal from the electrical signal;

[0125] Step 1045: Based on the correspondence between the light intensity and phase difference of the interference light signal, the sequence of phase change of the backscattered light signal over time is reconstructed from the periodic fluctuation component, and the sequence of phase change over time is used as the phase change amount.

[0126] In the above scheme, the phase change refers to the change in the phase of the light wave over time, which is used to characterize the vibration intensity and is calculated by a phase demodulation algorithm;

[0127] Dynamic change refers to the characteristics of the eddy current field changing over time, which is used to reflect the motion state of the UAV and is obtained through real-time monitoring;

[0128] The preset reference optical signal refers to the optical wave signal used as a comparison benchmark for interferometric measurements, and is generated through the reference optical path;

[0129] Interference optical signals refer to the interference pattern formed by the superposition of two beams of light, which is used to detect phase difference and is formed through the principle of optical interference.

[0130] Light intensity variation refers to the brightness fluctuation of the interference light signal, which is used to reflect phase information and is obtained through photoelectric detection;

[0131] Phase difference refers to the phase shift between two light waves, which is used to calculate deformation and is obtained through interference fringe analysis.

[0132] Electrical signals refer to the electrical parameters obtained after converting optical signals, which are used for signal processing and are obtained through photoelectric conversion.

[0133] Periodic fluctuation components refer to regularly changing components in a signal, used to extract vibration characteristics, and are obtained through signal filtering and separation.

[0134] A time-varying sequence refers to phase values ​​arranged in chronological order, used to record dynamic processes, and is obtained through continuous sampling.

[0135] In this scheme, the backscattered light signal and the reference light signal are first mixed using a 3x3 fiber coupler. The 3x3 fiber coupler uses its internal optical structure to cause the two light waves to interfere, generating three interference light signals with a fixed phase difference. Secondly, a balanced detector is used to detect the intensity change of the interference light signal. The balanced detector uses differential amplification technology to eliminate common-mode noise and converts the intensity difference between the two interference light signals into a voltage signal with a high signal-to-noise ratio. By monitoring the amplitude change of the voltage signal, the real-time phase difference between the backscattered light signal and the reference light signal can be accurately reflected.

[0136] Then, a bandpass filter is used to filter the electrical signal. By setting the passband range of the filter, only the periodic fluctuation component that matches the frequency of the micro-vibration signal is retained. The center frequency of the bandpass filter is set according to the typical rotational speed range of the UAV rotor, and the passband width is determined according to the fluctuation range of the vibration frequency. Finally, digital phase-locked loop technology is used for phase demodulation. The phase difference between the input signal and the local oscillator is compared by a phase detector. The loop filter is used to generate an error signal to control the voltage-controlled oscillator. Finally, a precise phase-time variation sequence is output as the phase change quantity.

[0137] For example, following a specific embodiment of the previous scheme, the obtained backscattered light signal is mixed with a reference light signal using a 3x3 fiber coupler. When the UAV flies at a frequency of 25Hz, the balance detector detects the intensity change of the interference light signal and outputs a voltage signal containing a 25Hz vibration component. The effective signal is extracted by a bandpass filter with a center frequency of 25Hz and a bandwidth of 5Hz. Finally, the filtered signal is processed by a digital phase-locked loop demodulation algorithm to obtain a digital sequence of phase changes over time recorded at a sampling rate of 1000Hz. This digital sequence is the required phase change, which accurately reflects the dynamic characteristics of the eddy current field.

[0138] This step constructs a complete phase demodulation system by employing a 3x3 coupler structure, balanced detection technology, and digital phase-locked loop algorithm. It achieves high-precision, real-time extraction of phase changes, effectively suppresses environmental noise interference, and provides a reliable phase information data source for subsequent signal processing.

[0139] Step 105: Based on the correlation between the phase change and the UAV flight parameters, the phase change is encoded into a digital eddy current feature sequence.

[0140] Optionally, step 105 may specifically include the following steps:

[0141] Step 1051: Divide the phase change amount into multiple consecutive time segments in chronological order;

[0142] Step 1052: Match a corresponding UAV flight parameter set for each time segment, wherein the flight parameter set includes the UAV's flight speed and rotor speed within the time segment;

[0143] Step 1053: Bind the average phase change amplitude and dominant phase change frequency within each time segment to the matched flight parameter set to form a data unit;

[0144] Step 1054: According to the time sequence of the time segment, convert the amplitude, frequency and flight parameter group in each data unit into digital codes of a predetermined format;

[0145] Step 1055: Combine the digital codes corresponding to the time segments in chronological order to obtain the digital eddy current feature sequence.

[0146] In the above scheme, the UAV flight parameters refer to the state data of the UAV during flight, which are used to describe flight characteristics and are obtained in real time through the flight control system;

[0147] Digital eddy current feature sequences refer to digitally encoded sequences arranged in chronological order, used to represent eddy current field characteristics, and are generated through encoding processing.

[0148] Multiple consecutive time segments refer to dividing the time axis into intervals of equal length for segmented data processing, which is obtained by dividing the time window.

[0149] Flight speed refers to the rate at which a drone moves horizontally, reflecting its flight status, and is obtained through GPS or an inertial measurement unit.

[0150] Rotor speed refers to the rotational speed of the UAV rotor, which is used to determine the eddy current field frequency and is measured by a motor encoder;

[0151] The average phase change amplitude refers to the average intensity of the phase change, which is used to characterize the magnitude of vibration. It is obtained by calculating the average value of the phase.

[0152] The dominant phase change frequency refers to the most significant frequency component in the phase change, used to identify the dominant vibration frequency, and is extracted through spectrum analysis.

[0153] A data unit refers to a collection of various types of data, used to integrate relevant information, and is formed through data binding operations;

[0154] Predefined format digital encoding refers to a data format arranged according to specific rules, used for standardized transmission, and generated through encoding algorithms.

[0155] In this scheme, firstly, a sliding time window algorithm is used to segment the phase change at fixed intervals of 1 second. Overlapping window technology is used to ensure data continuity, generating multiple continuous time segments, each containing phase data with a fixed number of sampling points. Secondly, timestamp alignment technology is used to accurately match each time segment with the UAV's flight parameters using the GPS time synchronization signal of the flight control system. A database query algorithm is used to extract the flight speed and rotor speed for the corresponding time period from the flight log, forming a time-synchronized flight parameter set.

[0156] Then, digital signal processing algorithms are applied to perform statistical analysis on the phase change in each time segment. The average phase change amplitude is obtained by calculating the arithmetic mean. The Fast Fourier Transform algorithm is used for spectrum analysis to extract the frequency component with the largest power spectral density as the dominant phase change frequency. Data encapsulation technology is used to bind these characteristic parameters with the flight parameter group into structured data units.

[0157] Next, a data serialization algorithm is used to convert the parameter values ​​in each data unit into digital codes according to a predefined communication protocol. Data type conversion technology is used to encode the amplitude and frequency values ​​of floating-point numbers and the flight parameters of integers into binary format. Finally, a data stream splicing algorithm is applied to connect the various digital codes in chronological order of time segments. Frame synchronization technology is used to add separators between each code segment. Checksum algorithm is used to ensure data integrity, and finally, a digital eddy current feature sequence with time series characteristics is generated.

[0158] For example, following the specific implementation of the previous scheme, based on the obtained phase change, a sliding time window algorithm is used to segment the time segment with a window length of 1 second and an overlap of 0.5 seconds. For the third segment, the flight speed of 8 m / s and the rotor speed of 1200 RPM are matched by querying the database. The average amplitude of 1024 phase sampling points in this time segment is calculated to be 0.5 radians, and the dominant frequency of 25 Hz is obtained by FFT analysis. These parameters are encapsulated in JSON format, converted into digital codes, and then spliced ​​in chronological order to form a complete digital eddy current feature sequence.

[0159] This step, through a systematic data processing workflow, transforms the raw phase information into a structured digital sequence, achieving effective fusion of vibration characteristics and flight parameters. It provides a standardized data format for remote transmission and subsequent analysis, ensuring the integrity and resolvability of the characteristic information.

[0160] Step 106: The digital eddy current feature sequence is transmitted to the remote monitoring platform via an optical fiber communication link to complete the transmission of the eddy current detection micro-vibration signal.

[0161] Optionally, step 106 may specifically include the following steps:

[0162] Step 1061: Encapsulate the digital eddy current feature sequence into continuous data packets according to a preset communication protocol;

[0163] Step 1062: Modulate the continuous data packets onto the optical carrier to generate an optical signal;

[0164] Step 1063: Inject the optical signal into the optical fiber communication link for transmission, and transmit the optical signal along the optical fiber toward the remote monitoring platform.

[0165] Step 1064: Receive the optical signal through the remote monitoring platform and demodulate the optical signal to restore the continuous data packets;

[0166] Step 1065: Parse the continuous data packets according to the preset communication protocol to recover the digital eddy current feature sequence.

[0167] In the above scheme, the optical fiber communication link refers to the optical fiber line used for optical signal transmission, which is used for remote data transmission and is obtained through the construction of an optical fiber network;

[0168] A remote monitoring platform refers to a monitoring center located at a remote location, used to receive and process data, and is constructed through a computer system.

[0169] Eddy current detection refers to the process of detecting eddy current fields, which is used to identify the status of drones and is achieved through a sensing system.

[0170] A predefined communication protocol refers to predefined data transmission rules used to standardize data formats and is determined through protocol design.

[0171] A continuous data packet refers to a data unit arranged in sequence, used for segmented transmission, and formed through data encapsulation.

[0172] Optical carrier refers to the light wave used to carry information and is used for signal transmission; it is generated by lasers.

[0173] Optical signals refer to light waves that carry information and are used for long-distance transmission. They are generated through modulation techniques.

[0174] In this scheme, firstly, the digital eddy current characteristic sequence is divided into fixed-length data segments according to the TCP / IP communication protocol using a data encapsulation algorithm. A header, checksum, and trailer information are added to each data segment to form a continuous data packet that conforms to the communication standard. Secondly, pulse code modulation technology is used to convert the binary signal of the continuous data packet into an electrical signal. The electrical signal is then loaded onto a 1550nm wavelength optical carrier using a laser modulator to generate an intensity-modulated optical signal.

[0175] Then, the optical signal is injected into the single-mode optical fiber communication link through an optical fiber coupler. The optical signal is transmitted in the optical fiber core by utilizing the principle of total internal reflection. Erbium-doped fiber amplifiers are used to periodically compensate for the optical signal loss during long-distance transmission to ensure signal transmission quality.

[0176] At the remote monitoring platform, the received optical signal is converted into an electrical signal by a photodetector, and the original data packet stream is restored by a demodulation circuit. Finally, the data packet boundary is identified according to the preset communication protocol by the protocol parsing algorithm, the payload is extracted, the encapsulation header and footer information is removed, and the data is recombined into a complete digital eddy current feature sequence.

[0177] For example, following a specific embodiment of the previous scheme, the obtained digital eddy current feature sequence is packaged and encapsulated at the data transmission end using a standard communication protocol; each data packet is given necessary header information and a checksum to ensure transmission integrity; the encapsulated data is converted into an optical signal by a laser modulator and injected into a single-mode fiber optic transmission link; the optical signal is transmitted to the remote monitoring center in the sensing fiber, where it is converted back into an electrical signal by an optical receiving device; the receiving end demodulates the electrical signal, identifies the data packet structure, verifies the checksum, and extracts the valid data; finally, it is reassembled into a complete digital eddy current feature sequence, completing reliable data transmission from the detection site to the monitoring center.

[0178] This step establishes a highly reliable transmission channel from the signal source to the monitoring center. Through a complete optical communication process, it realizes remote lossless transmission of detection data, ensuring the integrity and real-time nature of eddy current characteristic information, and providing a reliable data source for subsequent data analysis.

[0179] Figure 2 This application provides a schematic diagram of a micro-vibration signal transmission system for eddy current detection based on fiber optic sensing, as shown below. Figure 2 As shown, the system includes:

[0180] The control module 21 is used to control the UAV to fly within a preset area, so that the vortex field generated by the rotation of the UAV's rotor creates periodic pressure disturbances on the preset area, wherein the preset area is an area where sensing optical fibers are buried on the ground surface.

[0181] The generation module 22 is used to generate a micro-vibration signal based on the periodic pressure disturbance of the preset area by the eddy field, wherein the micro-vibration signal contains eddy characteristic information;

[0182] Conversion module 23 is used to convert the micro-vibration signal into a backscattered light signal based on the sensing fiber;

[0183] Extraction module 24 is used to perform phase demodulation on the backscattered light signal and extract the phase change, the phase change corresponding to the dynamic change of the eddy current field;

[0184] The encoding module 25 is used to encode the phase change amount into a digital eddy current feature sequence based on the correlation between the phase change amount and the UAV flight parameters;

[0185] The transmission module 26 is used to transmit the digital eddy current feature sequence to the remote monitoring platform through an optical fiber communication link to complete the transmission of the eddy current detection micro-vibration signal.

[0186] Figure 2 The aforementioned eddy current detection micro-vibration signal transmission system based on fiber optic sensing can perform... Figure 1The implementation principle and technical effects of the eddy current detection micro-vibration signal transmission method based on fiber optic sensing described in the illustrated embodiment will not be repeated here. The specific operation methods of each module and unit in the eddy current detection micro-vibration signal transmission system based on fiber optic sensing in the above embodiments have been described in detail in the embodiments related to this method, and will not be elaborated upon here.

[0187] In one possible design, Figure 2 The illustrated embodiment of an eddy current detection micro-vibration signal transmission system based on fiber optic sensing can be implemented as a computing device, such as... Figure 3 As shown, the computing device may include a storage component 31 and a processing component 32;

[0188] The storage component 31 stores one or more computer instructions, wherein the one or more computer instructions are invoked and executed by the processing component 32.

[0189] The processing component 32 is used for the above Figure 1 The embodiment describes a method for transmitting micro-vibration signals based on eddy current sensing using fiber optic sensing.

[0190] The processing component 32 may include one or more processors to execute computer instructions to complete all or part of the steps in the above-described method. Alternatively, the processing component may be implemented as one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above-described method.

[0191] Storage component 31 is configured to store various types of data to support operations at the terminal. The storage component can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0192] Of course, computing devices may also include other components, such as input / output interfaces, display components, communication components, etc.

[0193] Input / output interfaces provide interfaces between processing components and peripheral interface modules, which can be output devices, input devices, etc.

[0194] The communication components are configured to facilitate wired or wireless communication between computing devices and other devices.

[0195] The computing device can be a physical device or an elastic computing host provided by a cloud computing platform. In this case, the computing device can refer to a cloud server, and the aforementioned processing components, storage components, etc., can be basic server resources rented or purchased from the cloud computing platform.

[0196] This application also provides a computer storage medium storing a computer program, which, when executed by a computer, can perform the above-described functions. Figure 1 The embodiment shown is a method for transmitting micro-vibration signals based on eddy current sensing using fiber optic sensing.

[0197] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0198] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0199] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0200] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for transmitting micro-vibration signals detected by eddy current based on optical fiber sensing, characterized in that, include: Controlling a drone to fly within a preset area, causing the vortex field generated by the rotation of the drone's rotor to create periodic pressure disturbances on the preset area, wherein the preset area is an area where sensing optical fibers are buried on the ground surface; Based on the periodic pressure disturbance of the preset area by the eddy current field, a micro-vibration signal is generated, and the micro-vibration signal contains eddy current characteristic information. Based on the sensing fiber, the micro-vibration signal is converted into a backscattered light signal; The backscattered light signal is phase demodulated, and the phase change is extracted. The phase change corresponds to the dynamic change of the eddy current field. Based on the correlation between the phase change and the UAV flight parameters, the phase change is encoded into a digital eddy current feature sequence, including: dividing the phase change into multiple consecutive time segments in chronological order; matching a corresponding UAV flight parameter set to each time segment, the flight parameter set including the UAV's flight speed and rotor speed within the time segment; binding the average phase change amplitude and dominant phase change frequency within each time segment to the matched flight parameter set to form a data unit; converting the amplitude, frequency, and flight parameter set in each data unit into a predetermined digital code according to the chronological order of the time segments; and combining the digital codes corresponding to the time segments in chronological order to obtain the digital eddy current feature sequence. The digital eddy current feature sequence is transmitted to a remote monitoring platform via an optical fiber communication link to complete the transmission of micro-vibration signals for eddy current detection.

2. The method according to claim 1, characterized in that, The drone is controlled to fly within a preset area, causing the vortex field generated by the drone's rotor rotation to create periodic pressure disturbances in the preset area. The preset area is a region where sensing optical fibers are buried on the ground, including: The drone is controlled to fly along a preset flight path at a preset cruising altitude. By continuously rotating the drone's rotor, air is pushed downward at the preset cruising altitude, thereby generating a dynamic vortex field below the drone's rotor. The dynamic vortex field impacts the surface of the preset area, causing the air pressure on the surface to change periodically with the rotation frequency of the UAV's rotor and the flight speed of the UAV, thus generating periodic pressure disturbances.

3. The method according to claim 1, characterized in that, Based on the periodic pressure disturbance of the preset region by the eddy current field, a micro-vibration signal is generated. The micro-vibration signal contains eddy current characteristic information, including: The periodic pressure disturbance is applied to the surface of the preset area to be converted into a periodic mechanical force on the surface medium. The periodic mechanical force induces elastic deformation in the surface medium that is synchronized with the pressure change of the eddy current field, wherein the elastic deformation propagates in the surface medium in a predetermined direction in the form of stress waves. Stress waves are applied to the sensing optical fiber buried in the surface medium, causing the sensing optical fiber to generate corresponding mechanical vibrations according to the periodicity of the stress waves. The mechanical vibrations corresponding to the sensing optical fiber are recorded as micro-vibration signals.

4. The method according to claim 1, characterized in that, Based on the sensing fiber, the micro-vibration signal is converted into a backscattered light signal, including: Injecting continuous light waves into the sensing optical fiber, which serves as a distributed sensing medium; The micro-vibration signal causes local deformation of the sensing optical fiber, so that the optical phase of the continuous light wave is directly modulated at the deformation position when the continuous light wave is transmitted in the sensing optical fiber. Based on the change in optical phase, the mechanical vibration of the micro-vibration signal is converted into the continuous light wave to form a phase-modulated light wave; The backscattered light generated inside the sensing fiber by the phase-modulated light wave is collected to obtain the backscattered light signal.

5. The method according to claim 1, characterized in that, The backscattered light signal is phase demodulated to extract the phase change, which corresponds to the dynamic change of the eddy current field, including: The backscattered light signal is mixed with a preset reference light signal to generate an interference light signal; The intensity change of the interference light signal is detected, wherein the intensity change corresponds to the phase difference between the backscattered light signal and the reference light signal; The intensity change of the interference optical signal is converted into an electrical signal; Separate the periodic fluctuation component caused by the micro-vibration signal from the electrical signal; Based on the correspondence between the light intensity and phase difference of the interference light signal, the sequence of phase change of the backscattered light signal over time is reconstructed from the periodic fluctuation component, and the sequence of phase change over time is used as the phase change quantity.

6. The method according to claim 1, characterized in that, The digital eddy current feature sequence is transmitted to a remote monitoring platform via an optical fiber communication link to complete the transmission of micro-vibration signals detected by eddy current detection, including: The digital eddy current feature sequence is encapsulated into continuous data packets according to a preset communication protocol; Continuous data packets are modulated onto an optical carrier to generate an optical signal; The optical signal is injected into the optical fiber communication link used for transmission, and the optical signal is transmitted along the optical fiber towards the remote monitoring platform. The remote monitoring platform receives the optical signal and demodulates it to recover the continuous data packets. The continuous data packets are parsed according to the preset communication protocol to recover the digital eddy current feature sequence.

7. A micro-vibration signal transmission system for eddy current detection based on fiber optic sensing, characterized in that, include: The control module is used to control the drone to fly within a preset area, so that the vortex field generated by the rotation of the drone's rotor creates periodic pressure disturbances on the preset area, wherein the preset area is an area where sensing optical fibers are buried on the ground surface. The generation module is used to generate micro-vibration signals based on the periodic pressure disturbance of the preset area by the eddy field, wherein the micro-vibration signals contain eddy characteristic information. A conversion module is used to convert the micro-vibration signal into a backscattered light signal based on the sensing fiber; The extraction module is used to perform phase demodulation on the backscattered light signal and extract the phase change, which corresponds to the dynamic change of the eddy current field. An encoding module is used to encode the phase change amount into a digital eddy current feature sequence based on the correlation between the phase change amount and the UAV flight parameters. This includes: dividing the phase change amount into multiple consecutive time segments in chronological order; matching each time segment with a corresponding UAV flight parameter set, the flight parameter set including the UAV's flight speed and rotor speed within the time segment; binding the average phase change amplitude and dominant phase change frequency within each time segment to the matched flight parameter set to form a data unit; converting the amplitude, frequency, and flight parameter set in each data unit into a predetermined digital code according to the chronological order of the time segments; and combining the digital codes corresponding to the time segments in chronological order to obtain the digital eddy current feature sequence. The transmission module is used to transmit the digital eddy current feature sequence to a remote monitoring platform via an optical fiber communication link to complete the transmission of eddy current detection micro-vibration signals.

8. A computing device, characterized in that, It includes a processing component and a storage component; the storage component stores one or more computer instructions; the one or more computer instructions are invoked and executed by the processing component to implement the eddy current detection micro-vibration signal transmission method based on fiber optic sensing as described in any one of claims 1 to 6.

9. A computer storage medium, characterized in that, The device contains a computer program that, when executed by a computer, implements a method for transmitting micro-vibration signals based on eddy current sensing as described in any one of claims 1 to 6.

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