Optical fiber composite sensing array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure

Abstract

The invention belongs to the technical field of optical fiber sensing, and particularly relates to an optical fiber composite sensing array and edge demodulation device for long-distance infrastructure multi-parameter monitoring, and the optical fiber composite sensing array comprises a distributed temperature sensing channel, a distributed vibration sensing channel, an optical fiber grating sensing channel, a main sensing optical fiber, and a wavelength division multiplexing assembly. A wavelength separation device and a digital system; the edge demodulation device comprises a time synchronization mechanism, a data processing stream and a multi-parameter fusion model, a single main sensing optical fiber is utilized to integrate a distributed temperature sensing channel, a distributed vibration sensing channel and an optical fiber grating sensing channel, the edge demodulation device is arranged, and a multi-source data fusion model is constructed; and full-field synchronous reconstruction of a temperature field, a vibration event and strain distribution is realized, so that high-precision synchronous monitoring and real-time decision making of multiple physical quantities are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical fiber sensing, and in particular relates to an optical fiber composite sensing array and an edge demodulation device for multi-parameter monitoring of long-distance infrastructure. Background Art

[0002] Distributed fiber optic sensing (DOFS) technology, with its unique ability to perceive data over a wide range and continuously in space, fully integrates the light transmission and sensing properties of optical fibers. It can simultaneously acquire information about the distribution of the measured field in both time and space, demonstrating irreplaceable application potential in areas such as infrastructure health monitoring. Distributed fiber optic sensing technologies based on various physical mechanisms have been extensively researched, including Rayleigh scattering, Raman scattering, Brillouin scattering, fiber interferometers, and fiber Bragg gratings (FBGs). Despite extensive research on single-mechanism sensing technologies, their application in complex engineering scenarios still faces significant limitations.

[0003] Currently, research on distributed fiber-optic sensors targeting a single mechanism is relatively intensive. For example, patent application CN101324424A discloses a novel fiber-optic Brillouin optical time-domain analyzer (OTDA) that exploits the strain and temperature effects of Brillouin scattered light using broadband nonlinear optical amplification and related methods. The device comprises a narrowband single-frequency fiber laser, a fiber splitter, a pulse modulator, two fiber circulators, a heterodyne receiver digital signal processor, a fiber Bragg grating filter, a single-mode fiber, and a continuously operating fiber Raman pump laser. This technology primarily achieves strain and temperature measurement through fiber-optic Brillouin optical time-domain analysis (BOTDA), leveraging the fiber's nonlinear amplification effect to improve the signal-to-noise ratio. However, this technology is only suitable for static or quasi-static parameter monitoring and cannot capture high-frequency vibration events such as mechanical shock or pipeline leaks. Furthermore, the system is complex, requiring multiple pump lasers and circulators.

[0004] A Chinese patent with authorization publication number CN1232846C discloses a Mach-Zehnder interferometer sensor device based on a microbend transmission waveguide. One end of the input optical waveguide of the sensor device is connected to a laser light source, and the other end is connected to one end of a first coupler. These are then connected to a bent sensing optical waveguide arm and one end of a bent reference optical waveguide arm, respectively. The output optical waveguide is then connected via a second coupler. A sensing sample cell is mounted on the outside of the sensing optical waveguide arm, and a standard sample cell is mounted on the outside of the reference optical waveguide arm. This patent proposes an interferometer sensor device based on a microbend waveguide that detects external disturbances by detecting the phase difference between the reference arm and the sensing arm. This type of solution has limited spatial resolution, typically >10 μm, and has difficulty distinguishing between temperature and strain coupling effects, making it susceptible to interference from environmental noise.

[0005] Patent application publication number CN102818657 A discloses a remote distributed Raman temperature sensor based on EDFA amplification technology. The sensor is characterized by at least two sensing fibers, with two circulators and amplifiers positioned between the two adjacent sensing fibers. The signal from the previous sensing fiber passes through the first circulator, the EDFA amplifier, and the second circulator before entering the next sensing fiber. The backreflected signal from the next sensing fiber passes through the second circulator, the first circulator, and then returns to the previous sensing fiber and is fed into a data collector via a wavelength division multiplexer. This patent uses EDFA amplification technology to extend the Raman temperature measurement distance, achieving a multi-stage fiber link by cascading circulators and amplifiers. However, this technology cannot synchronously sense vibration or strain, and the additional noise introduced by the amplifier reduces temperature measurement accuracy.

[0006] The above existing technologies are restricted by their respective technical characteristics. In some complex engineering scenarios such as oil pipelines, high-voltage cables, bridges, etc., it is difficult to simultaneously perform high-precision collaborative monitoring of static parameters such as temperature and long-term strain, and dynamic parameters such as vibration and transient stress. Summary of the Invention

[0007] In order to realize the research on multi-parameter distributed optical fiber sensors, the present invention provides an optical fiber composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure.

[0008] The specific technical solutions of the present invention are as follows: An optical fiber composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure, the optical fiber composite sensor array comprising: A distributed temperature sensing channel is provided with a laser, an acousto-optic modulator, and a detection module. The acousto-optic modulator generates controllable light pulses, and the detection module implements pulse power monitoring and feedback regulation. A distributed vibration sensing channel is provided with a second laser, a phase modulator, and a second detection module. The phase modulator is loaded with a high-complexity coding sequence, and the second detection module verifies the integrity of the modulated signal. The fiber Bragg grating sensing channel is provided with a third laser, a tunable filter and a circulator. The tunable filter generates a wavelength scanning beam, and the circulator realizes directional transmission of optical signals. The main sensing fiber has an FBG array inside, which can selectively reflect specific wavelengths and transmit the transmission wavelengths. The wavelength division multiplexing component includes three independent wavelength division multiplexers. The WDM1 port, WDM2 port, and WDM3 port receive three-channel optical signals respectively and merge them into a single main sensing optical fiber through a fiber coupler; Wavelength separation device, demultiplexing the Rayleigh backscattered light and directing different wavelength signals to the DTS detector and DVS detector respectively; Digital system, collects and processes all signals after photoelectric conversion; The edge demodulation device comprises: Time synchronization mechanism, equipped with GPS receiving unit, PTP precision clock protocol unit and FPGA timestamp alignment circuit; A data processing flow is provided with a signal acquisition unit and a feature extraction unit working in parallel, wherein the feature extraction unit executes a temperature analysis module, a vibration analysis module, and a strain analysis module in parallel; The multi-parameter fusion model integrates multi-dimensional information of temperature, vibration, and strain for joint processing and analysis and outputs decision instructions.

[0009] Furthermore, the multi-parameter fusion model also includes an abnormal decision engine and a multi-mode alarm output module. The abnormal decision engine implements a hierarchical judgment strategy, combined with dynamic threshold adjustment and spatiotemporal correlation analysis. The multi-mode alarm output module drives the on-site sound and light alarm device through relay control, uploads equipment status data through the industrial communication interface, and transmits positioning information to the central monitoring platform in real time through the high-speed network channel.

[0010] Furthermore, the FBG array inside the main sensing fiber is arranged regularly, and a group of grating units with characteristic reflection spectra are set at a certain interval. The grating reflection signal returns to the circulator along the original transmission path, enters the circulator port 2, and outputs the circulator port 3, and is guided to the FBG detector.

[0011] Furthermore, the time synchronization mechanism adopts a dual-path redundant design architecture.

[0012] Furthermore, the GPS receiving unit is used to obtain the absolute time reference provided by satellite positioning, the PTP precision clock protocol unit is used to achieve high-precision time synchronization in a network environment, and the FPGA timestamp alignment circuit performs intelligent calibration and compensation on the two input time signals.

[0013] Furthermore, the temperature analysis module is used to identify spatial temperature anomalies, the vibration analysis module calculates energy distribution through frequency domain transformation, and the strain analysis module implements window detection of dynamic baseline calibration.

[0014] Furthermore, the laser 1 is a distributed feedback laser with a wavelength of 1550 nm, and the laser 1 is connected to the acousto-optic modulator via a polarization-maintaining optical fiber.

[0015] Furthermore, the second laser provides a 1650nm light source, which enters the phase modulator after polarization optimization.

[0016] Furthermore, the entire optical transmission line adopts a multi-stabilization design to ensure stable wavelength characteristics through thermal management and mechanical protection.

[0017] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art: The present invention uses wavelength multiplexing technology to achieve single-fiber transmission and multi-parameter synchronous sensing. Through a specific wavelength allocation scheme, the three functions of distributed temperature sensing, vibration detection, and fiber Bragg grating strain measurement are physically isolated at the optical layer, completely solving the crosstalk problem of traditional multi-system parallel connection. The edge demodulation device has a built-in dual-redundant time synchronization mechanism, combined with the original signal parallel acquisition architecture, to ensure that the time alignment accuracy of multi-source heterogeneous data meets industrial application standards; An innovative multi-stage data processing flow eliminates data transmission bandwidth limitations through localized feature extraction. The temperature analysis module identifies temperature anomaly characteristics, the vibration analysis module establishes a frequency-domain energy distribution model, and the strain analysis module implements dynamic baseline calibration. The outputs of these three modules are combined through a multi-parameter fusion model to generate joint decision instructions, triggering multi-mode alarm outputs, significantly improving the accuracy and timeliness of anomaly identification. In addition, the system uses a modular optoelectronic design to achieve hardware-layer decoupling and supports wavelength configuration reconstruction through pluggable wavelength division multiplexing components, giving the system the ability to adapt to multiple scenarios. The multi-protection design enables the device to maintain measurement stability in harsh environments. Compared with traditional solutions, this invention has made substantial progress in expanding monitoring dimensions, improving real-time response, environmental anti-interference capabilities, and system reliability, providing a new generation of technology paradigm for the field of fiber optic sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural block diagram of the three-wavelength composite transmission architecture of the optical fiber composite sensor array of the present invention; Figure 2 It is a structural block diagram of the edge demodulation device of the present invention; Figure 3 This is a schematic diagram of the principle structure of the present invention.

[0019] The reference numerals are as follows: 1-Laser 1; 2-Acousto-Optic Modulator; 3-Detection Module 1; 4-WDM1 Port; 5-Laser 2; 6-Phase Modulator; 7-Detection Module 2; 8-WDM2 Port; 9-Laser 3; 10-Tunable Filter; 11-Fiber Coupler; 12-WDM3 Port; 13-Main Sensing Fiber; 14-FBG Array; 15-FBG Detector; 16-Wavelength Separator; 17-DTS Detector; 18-DVS Detector; 19-Edge Demodulator; 20 -Time synchronization mechanism; 21-Data processing flow; 22-Multi-parameter fusion model; 23-GPS receiving unit; 24-PTP precision clock protocol unit; 25-FPGA timestamp alignment circuit; 26-Signal acquisition unit; 27-Feature extraction unit; 28-Temperature analysis module; 29-Vibration analysis module; 30-Strain analysis module; 31-Abnormal decision engine; 32-Multi-mode alarm output module; 33-Relay control; 34-Industrial communication interface; 35-High-speed network channel. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. Based on the embodiments, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] Combined with attachment Figure 1-3 As shown, a fiber optic composite sensor array and an edge demodulation device for long-distance infrastructure multi-parameter monitoring, the fiber optic composite sensor array includes: The distributed temperature sensing channel is provided with a laser 1, an acousto-optic modulator 2, and a detection module 3. The acousto-optic modulator 2 generates controllable optical pulses, and the detection module 3 implements pulse power monitoring and feedback adjustment. That is, the detection module 3 realizes real-time monitoring and calibration of pulse energy to ensure stable pulse quality before connecting to port 4 of the high-isolation wavelength division multiplexer WDM1. The distributed vibration sensing channel is provided with a second laser 5, a phase modulator 6 and a second detection module 7. The phase modulator 6 is loaded with a high-complexity coding sequence. The second detection module 7 verifies the integrity of the modulated signal. That is, the integrity of the modulated signal is verified by the second detection module 7. After ensuring that the signal quality meets the standard, it is connected to the wavelength division multiplexer WDM2 port 8; The fiber Bragg grating sensing channel is provided with a laser 3 9, a tunable filter 10 and a circulator. The laser 3 9 mainly provides a 1545nm light source, which is precisely filtered by the tunable filter 10 to form a narrow linewidth scanning beam. After the optical signal is directional transmitted through the circulator, the input of the circulator port 1 and the output of the circulator port 2 are connected to the wavelength division multiplexer WDM3 port 12; The main sensing fiber 13 has an FBG array 14 disposed therein, which selectively reflects a specific wavelength band and maintains transmission in the transmission wavelength band; The wavelength division multiplexing component includes three independent wavelength division multiplexers, wherein the WDM1 port 4, the WDM2 port 8 and the WDM3 port 12 respectively receive three channel optical signals and merge them into a single main sensing optical fiber 13 through a fiber coupler 11; The wavelength separation device 16 demultiplexes the Rayleigh backscattered light and directs the different wavelength signals to the DTS detector 17 and DVS detector 18, respectively. The 1550nm band signal is received by the temperature-optimized DTS detector 17, while the 1650nm band signal is input to the ultra-low-noise DVS detector 18. This unique wavelength allocation scheme enables high-isolation parallel transmission of the three sensing channels, laying the physical foundation for simultaneous multi-parameter monitoring. Digital system, collects and processes all signals after photoelectric conversion; The edge demodulation device 19 is the intelligent processing hub of the entire optical fiber sensing system, which includes: The time synchronization mechanism 20 is provided with a GPS receiving unit 23, a PTP precision clock protocol unit 24 and an FPGA timestamp alignment circuit 25; The data processing flow 21 is provided with a signal acquisition unit 26 and a feature extraction unit 27 working in parallel. The signal acquisition unit 26 collects the signals received synchronously by the digital system from the FBG, DTS and DVS detectors; The feature extraction unit 27 executes the temperature analysis module 28, the vibration analysis module 29 and the strain analysis module 30 in parallel; The multi-parameter fusion model 22 integrates the multi-dimensional information of temperature, vibration, and strain for joint processing and analysis and outputs decision instructions. That is, the multi-parameter fusion model 22 makes a joint decision on the characteristic parameters of the three channels in order to build a comprehensive understanding of the working conditions.

[0022] Specifically, the multi-parameter fusion model 22 also includes an abnormality decision engine 31 and a multi-mode alarm output module 32. The abnormality decision engine 31 implements a hierarchical judgment strategy, combines dynamic threshold adjustment and spatiotemporal correlation analysis, and then triggers the multi-mode alarm output module 32 according to the fusion results. The multi-mode alarm output module 32 includes a relay control 33, an industrial communication interface 34 and a high-speed network channel 35. The on-site sound and light alarm device is driven by the relay control 33, the equipment status data is uploaded through the industrial communication interface 34, and the positioning information is transmitted to the central monitoring platform in real time by the high-speed network channel 35.

[0023] Specifically, the FBG array 14 within the main sensing fiber 13 is regularly arranged, with a group of grating elements with characteristic reflection spectra spaced at regular intervals. Each group of grating elements contains multiple characteristic reflection wavelengths, and the total reflectivity is below a set threshold. The grating reflection signal returns to the circulator along the original transmission path, undergoes port switching, and is directed to the FBG detector 15, a highly sensitive FBG photodetector.

[0024] Specifically, the time synchronization mechanism 20 adopts a dual-path redundant design architecture.

[0025] Specifically, the GPS receiving unit 23 is used to obtain the absolute time reference provided by satellite positioning, the PTP precision clock protocol unit 24 is used to achieve high-precision time synchronization in a network environment, and the FPGA timestamp alignment circuit 25 performs intelligent calibration and compensation on the two input time signals to ensure that the time alignment accuracy of each detection module in the entire system meets industrial standards.

[0026] Specifically, the temperature analysis module 28, namely temperature gradient analysis, is used to identify spatial temperature anomalies, focusing on identifying temperature anomalies such as pipeline leakage. The vibration analysis module 29, namely vibration energy spectrum analysis, calculates energy distribution through frequency domain transformation, and can accurately capture intrusion events and mechanical failure characteristics. The strain analysis module 30, namely strain extreme value tracking, implements window detection with dynamic baseline calibration, and can continuously monitor the deformation state of structures such as bridges.

[0027] Specifically, the laser 1 adopts a distributed feedback laser with a wavelength of 1550nm, and the laser 1 is connected to the acousto-optic modulator 2 through a polarization-maintaining optical fiber. The acousto-optic modulator 2 generates a precisely controllable optical pulse signal under the drive of a digital control system.

[0028] Specifically, the laser 2 5 provides a 1650 nm light source, which enters the phase modulator 6 after polarization optimization.

[0029] Specifically, the entire optical transmission line adopts a multi-stabilization design, ensuring the stability of wavelength characteristics through thermal management and mechanical protection, so as to maintain stable operation in harsh environments and provide reliable decision-making support for infrastructure security monitoring.

[0030] To ensure optical stability, a corresponding laser temperature control module can be installed at each laser to maintain the stability of the laser source wavelength; an optical fiber stress relief structure can be set on the entire system transmission optical path to suppress transmission loss; and an optical isolation component can be installed to block reverse interference signals.

[0031] Wavelength allocation is used to achieve physical isolation and transmission of three-channel optical signals within a single fiber; the wavelength selectivity of the FBG array 14 is used to separate the reflected signal and the transmitted scattered light; based on the dual redundant time synchronization mechanism 20, multi-channel signal time domain alignment is established, that is, satellite timing signals and network synchronization signals are received, and timestamp alignment is achieved through logic device interpolation compensation; temperature scattering characteristics, vibration phase characteristics and strain wavelength characteristics are extracted in parallel through the feature extraction unit 27; a joint decision instruction is generated by the adaptive fusion algorithm of the multi-parameter fusion model 22; and a multi-mode alarm output module 32 is triggered; the adaptive fusion algorithm adopts a machine learning model, and the input parameters include temperature gradient value, vibration energy value and strain offset.

[0032] The specific implementation path of the present invention is as follows: During the optical signal generation phase, the distributed temperature sensing channel uses a 1550nm laser source to generate adjustable pulse width optical pulses through an acousto-optic modulator (AOM) 2. Pulse energy stability is maintained through feedback power monitoring in detection module 3. The distributed vibration sensing channel utilizes a 1650nm light source for phase encoding. Polarization optimization and coherent detection by phase modulator 6 ensure the integrity of the modulated signal. The fiber grating (FBG) monitoring channel utilizes a wavelength-scanning narrow-linewidth light source, and a circulator is used to construct a unidirectional optical transmission system. The three independently modulated optical signals are fed into a dedicated wavelength division multiplexer and converged via a fiber coupler 11 onto a single main sensing fiber 13. This fiber is internally engraved with a wavelength-selective grating array (FBG) array 14, enabling directional reflection in the monitoring band while maintaining high transmittance in the transmission band.

[0033] The optical signal separation process utilizes a physical-layer decoupling design: the fiber Bragg grating reflected signal propagates back along the incident optical path, and is spatially isolated from the incident light by switching at the circulator port. The backscattered Rayleigh light generated by the main sensing fiber 13 is separated by wavelength separation device 16. The scattered light in the 1550nm band represents temperature distribution information, while the scattered light in the 1650nm band carries vibration modulation characteristics. Each wavelength channel is equipped with an independent detector for photoelectric conversion. The temperature channel (DTS) uses a temperature-optimized detector to suppress thermal drift, and the vibration channel (DVS) incorporates a low-noise amplifier link to enhance perturbation detection sensitivity.

[0034] Signal collaborative processing achieves time-space synchronization through an edge demodulator 19. A time synchronization mechanism 20 integrates satellite timing and network timing references, aligning timestamps via a programmable logic device. The data processing flow 21 implements multi-channel parallel analysis. The temperature analysis module 28 analyzes the attenuation characteristics of scattering intensity with fiber length, the vibration analysis module 29 demodulates the time-domain perturbation pattern of the phase signal, and the strain analysis module 30 tracks characteristic wavelength drift. The three characteristic parameters are input into a multi-parameter fusion model 22, which uses an adaptive weighting algorithm to make joint decisions based on these three channel characteristic parameters. The anomaly decision engine 31 implements a hierarchical judgment strategy, combining dynamic threshold adjustment and spatiotemporal correlation analysis. The fusion results then trigger a multi-mode alarm output module 32. This module, via relay control 33, activates on-site audible and visual alarms, uploads device status data via an industrial communication interface 34, and transmits location information in real time to a central monitoring platform via a high-speed network channel 35.

[0035] Optical stability is achieved through a multi-layered security mechanism: precision temperature control modules are installed on each laser to suppress wavelength drift, stress-relief packaging is used in the transmission optical path to reduce microbend losses, and optical isolators are installed at key nodes to prevent reverse interference. The entire optical system achieves physical layer channel isolation through wavelength allocation. Combined with optical device parameter matching design, the system maintains signal integrity in each channel even over long transmission distances, providing the fundamental optical support for high-precision, synchronous monitoring of multiple parameters.

[0036] The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any modification and replacement based on the technical solution and inventive concept provided by the present invention should be included in the protection scope of the present invention.

Claims

1. Fiber optic composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure, characterized by: The optical fiber composite sensing array comprises: A distributed temperature sensing channel is provided with a laser (1), an acousto-optic modulator (2) and a detection module (3), wherein the acousto-optic modulator (2) generates a controllable light pulse, and the detection module (3) implements pulse power monitoring and feedback regulation; A distributed vibration sensing channel is provided with a second laser (5), a phase modulator (6) and a second detection module (7), wherein the phase modulator (6) loads a high-complexity coding sequence, and the second detection module (7) verifies the integrity of the modulated signal; A fiber Bragg grating sensing channel is provided with a third laser (9), a tunable filter (10) and a circulator, wherein the tunable filter (10) generates a wavelength scanning light beam and the circulator realizes directional transmission of optical signals; A main sensing optical fiber (13) is provided with an FBG array (14) therein, which selectively reflects a specific wavelength band and maintains transmission in a transmission wavelength band; A wavelength division multiplexing component, comprising three independent wavelength division multiplexers, wherein the WDM1 port (4), the WDM2 port (8) and the WDM3 port (12) respectively receive three channel optical signals and merge them into a single main sensing optical fiber (13) through an optical fiber coupler (11); a wavelength separation device (16) for demultiplexing the backscattered Rayleigh light and directing the signals of different wavelengths to the DTS detector (17) and the DVS detector (18); Digital system, collects and processes all signals after photoelectric conversion; The edge demodulation device (19) comprises: A time synchronization mechanism (20) is provided with a GPS receiving unit (23), a PTP precision clock protocol unit (24) and an FPGA timestamp alignment circuit (25); A data processing flow (21) is provided with a signal acquisition unit (26) and a feature extraction unit (27) operating in parallel, wherein the feature extraction unit (27) executes a temperature analysis module (28), a vibration analysis module (29) and a strain analysis module (30) in parallel; The multi-parameter fusion model (22) integrates the multi-dimensional information of temperature, vibration, and strain for joint processing and analysis and outputs decision instructions.

2. The optical fiber composite sensor array and edge demodulation device for long-distance infrastructure multi-parameter monitoring according to claim 1, characterized in that: The multi-parameter fusion model (22) further includes an abnormality decision engine (31) and a multi-mode alarm output module (32). The abnormality decision engine (31) implements a hierarchical judgment strategy, combined with dynamic threshold adjustment and spatiotemporal correlation analysis. The multi-mode alarm output module (32) drives the on-site sound and light alarm device through a relay control (33), uploads device status data through an industrial communication interface (34), and transmits positioning information to a central monitoring platform in real time through a high-speed network channel (35).

3. The optical fiber composite sensor array and edge demodulation device for long-distance infrastructure multi-parameter monitoring according to claim 1, characterized in that: The FBG array (14) inside the main sensing optical fiber (13) is regularly arranged, and a group of grating units with characteristic reflection spectra are arranged at a certain interval. The grating reflection signal returns to the circulator along the original transmission path, enters the circulator port 2, and outputs the circulator port 3, and is guided to the FBG detector (15).

4. The optical fiber composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure according to claim 1, characterized in that: The time synchronization mechanism (20) adopts a dual-path redundant design architecture.

5. The optical fiber composite sensor array and edge demodulation device for long-distance infrastructure multi-parameter monitoring according to claim 1, characterized in that: The GPS receiving unit (23) is used to obtain the absolute time reference provided by satellite positioning, the PTP precision clock protocol unit (24) is used to achieve high-precision time synchronization in a network environment, and the FPGA timestamp alignment circuit (25) performs intelligent calibration and compensation on the two input time signals.

6. The optical fiber composite sensor array and edge demodulation device for long-distance infrastructure multi-parameter monitoring according to claim 1, characterized in that: The temperature analysis module (28) is used to identify spatial temperature anomalies, the vibration analysis module (29) calculates energy distribution through frequency domain transformation, and the strain analysis module (30) implements window detection of dynamic baseline calibration.

7. The optical fiber composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure according to claim 1, characterized in that: The laser one (1) adopts a distributed feedback laser with a wavelength of 1550nm, and the laser one (1) is connected to the acousto-optic modulator (2) through a polarization-maintaining optical fiber.

8. The optical fiber composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure according to claim 1, characterized in that: The second laser (5) provides a 1650nm light source, which enters the phase modulator (6) after polarization optimization.

9. The optical fiber composite sensor array and edge demodulation device for multi-parameter monitoring of long-distance infrastructure according to claim 1, characterized in that: The entire optical transmission line adopts a multi-stabilization design to ensure stable wavelength characteristics through thermal management and mechanical protection.

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