3048results about "Converting sensor output optically" patented technology

The invention provides a wavelength division multiplexing-fused multi-core optical fiber temperature detection method and system. Wherein the broadband light source is divided into multiple wavelength channels through wavelength division multiplexing, and a wavelength-fiber core mapping relation is established, so that each fiber core of the multi-core optical fiber transmits a single-wavelength optical signal. An optical fiber is integrated to the surface of an object according to a three-dimensional path, each fiber core covers a plurality of sensing sub-areas, the wavelength drift amount caused by temperature is extracted by detecting the attenuation characteristic of an optical signal at a bending position, the wavelength drift amount is converted into a temperature value in combination with a calibration curve, and a temperature gradient model bound with the fiber core position is constructed. And further performing spatial solution by using fiber core spacing, wavelength mapping and transmission time delay parameters, establishing a corresponding relationship between the coordinates of the sensing sub-regions and the temperature, and finally reconstructing three-dimensional temperature field distribution. According to the technical scheme provided by the invention, high-resolution dynamic reconstruction and gradient analysis of a three-dimensional temperature field on a complex surface are realized through wavelength-space two-dimensional decoupling.

The invention relates to an optical fiber implantation monitoring method and device for composite material pressure-bearing equipment, and belongs to the technical field of composite material structure monitoring and intelligent sensing. According to the method, a distributed or point type optical fiber sensor and a composite material are synchronously integrated by designing a winding process, so that state parameters such as strain, temperature, pressure and the like of a key area of equipment are monitored in real time. The stability and the precision of the optical fiber in the laying process are ensured by adopting tool structures such as an embedded guide rail and an intelligent pay-off device; the tolerance and the coupling efficiency of the optical fiber are improved by combining the multi-layer structure design of the optical fiber flexible coating glue, the elastic coupling layer and the like; fBG, Brillouin and Raman sensing are fused through a temperature-stress cooperative monitoring system, and high-precision multi-physical field sensing is achieved. The system has the advantages of high integration level, low transformation cost and excellent monitoring performance, and is suitable for on-line health monitoring and intelligent early warning of composite material pressure-bearing equipment such as low-temperature high-pressure hydrogen storage cylinders, carbon fiber V-shaped cylinders and composite material pressure pipelines.

The invention provides a wavelength deviation compensation method and system for rapid wavelength analysis of a far-end fiber bragg grating, and relates to the technical field of fiber bragg grating sensing, and the method comprises the steps: collecting grating reflection spectrum signals of different transmission distances, carrying out frequency domain transformation to separate phase components, and building a mapping relation between the transmission distance and dispersion cumulant; calculating an initial wavelength offset estimation value; identifying a refractive index section, and establishing a segmentation compensation coefficient; constructing a wavelength-strain-temperature three-dimensional space, and optimizing a compensation coefficient according to the trajectory curvature; and updating the compensation coefficient according to the residual gradient. The wavelength analysis precision of the far-end fiber bragg grating can be improved, and the influence of dispersion on measurement is reduced.

The invention discloses an optical frequency domain reflection strain sensing method based on the combination of phase demodulation and cross-correlation, and the method comprises the steps: collecting backward Rayleigh scattering signals before and after the strain of a to-be-measured optical fiber, and extracting the phase information of a reference signal and a measurement signal through Fourier transform; a cross-correlation algorithm is combined to match a reference signal and a measurement signal at the same position of the optical fiber, and a dislocation phenomenon on a distance domain is corrected; calculating the relative phase of the matched reference signal and measurement signal at the same position, and performing phase unwrapping; distinguishing a fiber grating area and a non-grating area, and performing continuous correction on phase data by adopting a linear regression fitting algorithm so as to eliminate jump errors; on the basis of the differential relative phase, a window where the sudden change position is located is determined according to the window width obtained in the cross-correlation algorithm, segmented assignment is conducted on the strain of the window, and finally complete strain field distribution data are output. According to the method, the stability, the anti-interference capability and the measurement reliability of the phase demodulation method are improved.

The invention relates to the technical field of optical fiber sensing, and discloses an optical fiber sensing signal adaptive demodulation analysis method for inhibiting common-mode interference, which comprises the following steps of: synchronously acquiring an original signal of a main sensing optical fiber channel and a common-mode interference signal of a reference optical fiber channel, and performing time-frequency conjoint analysis on the signal of the reference optical fiber channel to obtain a common-mode interference signal; s2, extracting an interference spectrum component containing temperature drift and light source fluctuation characteristics, constructing a hybrid adaptive filter bank which comprises a recursive least square (RLS) filter and a variable step size least mean square (LMS) filter which are connected in parallel, and dynamically adjusting a forgetting factor of the RLS filter and a step size factor of the LMS filter based on the interference spectrum component extracted in the step S2, according to the optical fiber sensing signal adaptive demodulation analysis method for suppressing common-mode interference, a parameter adjustment strategy is continuously optimized, a pure vibration signal with an output signal-to-noise ratio is improved, and the effect of accurately suppressing common-mode interference in real time is achieved.

An integrated system for detecting dam breaches, as an early warning system and for evacuation assistance, consisting of: A geoinformatics analysis module comprising a modeling processor with a graphics processing unit, configured to: analyze spatial, hydrological, and topographic data of a dam and its downstream area; generate hydrological models using probable maximum rainfall (PMP) data to determine probable maximum flood discharge (PMF); generate hydraulic models to simulate flood propagation and determine flood depth, flood extent, flow velocity, and flood arrival time; create flood vulnerability models, vulnerability models, and flood hotspot models using a multi-criteria decision-making (MCDM) framework; and generate evacuation plans for high-risk zones based on the models. A sensor monitoring subsystem includes: a distributed fiber optic sensor (DFOS) configured to monitor the structural load and deformation of a dam, and a radar level gauge configured to measure the water level in the reservoir; a microcontroller unit configured to receive and process sensor data from the sensor monitoring subsystem, to detect dam breaches based on abnormal structural movements detected by the DFOS or sudden drops in water level below predefined thresholds detected by the radar level gauge; a communication module configured to transmit warning messages when dam breaches are detected; a warning system configured to: send SMS notifications to residents in downstream high-risk zones via a GSM communication module, generate real-time alerts via an IoT platform on user devices, and activate siren systems in villages to issue loud alarms and voice announcements; and an evacuation assistance platform configured to provide real-time evacuation assistance in emergencies due to dam breaks, displaying site maps with nearby emergency shelters, evacuation routes, hospitals, government buildings and aid centers, showing hydrological layers including flood extent, water depth, flow velocity and arrival time of the water, and enabling real-time location tracking in relation to safety zones and flood-prone areas.

The invention relates to the technical field of encoders, in particular to an incremental optical encoder signal error compensation system and method.The incremental optical encoder signal error compensation system comprises a signal acquisition module, a preprocessing module, an error analysis module, a compensation operation module, a data storage module and an output control module; the preprocessing module preprocesses the original signal; the error analysis module analyzes and identifies the error type and characteristics of the processing signal in a multi-dimensional manner, and calculates compensation values of the scribing error, the subdivision error and the eccentric error through the compensation operation module; a compensation value is superposed with an original signal, a compensated high-precision signal is obtained, the output control module outputs the high-precision signal to a subsequent device, meanwhile, system parameters are adjusted according to an external instruction, a high-precision error model is constructed by the system, and the high-precision error model is obtained by combining an advanced digital signal processing technology and an intelligent algorithm. And the scribing error, the subdivision error, the eccentric error and the like of the encoder are effectively compensated.

The invention provides a tunnel deformation monitoring system and method based on a distributed optical fiber sensing technology, and relates to the technical field of tunnel monitoring. A spiral winding type optical fiber is arranged in the longitudinal axis direction of the surface of a tunnel lining, a transverse optical fiber is arranged on a key section, and the data acquisition frequency is set to be 1Hz. Dividing the optical fiber into a plurality of data acquisition points at equal intervals, obtaining the real-time temperature and Brillouin frequency shift change of each point, measuring the temperature and strain sensitivity coefficient, and calculating the total strain; calculating long-term temperature strain compensation based on the long-term temperature component, generating an instantaneous temperature difference through the real-time temperature and the long-term temperature component, further calculating instantaneous temperature strain compensation, subtracting the two kinds of strain compensation from the total strain to obtain stress strain, and evaluating the deformation level of the tunnel based on the stress strain. And the accuracy of evaluation is judged through clustering analysis.

The invention provides a high and low temperature alternating environment temperature and pressure mixed signal decoupling method and system based on a multi-core optical fiber. According to the method, temperature and pressure mixed signals are synchronously acquired through phase difference data of a plurality of fiber cores, and multi-channel mixed sensing signals are generated; performing mechanical stress suppression on the multi-core optical fiber by using a thermal expansion adaptive packaging structure to form an anti-deformation optical fiber assembly; carrying out adaptive time slot distribution on the mixed sensing signal based on a time division multiplexing time sequence to generate a synchronous calibration signal; spectral features of the synchronous calibration signals are separated through the spectral analysis technology, scanning parameters are dynamically adjusted in combination with the temperature change rate and the deformation quantity, and temperature and pressure feature data are extracted; and performing decoupling operation on the feature data through the coupling model, and dynamically correcting the model parameter weight based on the deformation quantity feedback data to obtain a temperature parameter and a pressure parameter. According to the invention, the accuracy of synchronous decoupling measurement of temperature and pressure in a high-low temperature alternating environment is realized.

The invention provides a highway automatic monitoring system, and relates to the technical field of monitoring systems, and the system comprises an intelligent sensing layer which carries out the data collection and preliminary processing, and outputs structured data and an original video stream to an edge calculation layer. The edge computing layer receives the data of the sensing layer and outputs a local event alarm and prediction result to the central decision-making system, the central decision-making system performs global analysis and strategy generation and issues a grading processing instruction to the collaborative early warning platform, and each terminal performs linkage response through information distribution and execution of the collaborative early warning platform; the highway automatic monitoring system realizes road environment total factor perception through the multi-source sensing array, the video analysis unit and the pavement state monitoring module of the intelligent perception layer, effectively integrates multi-source data through a spatio-temporal data fusion technology, significantly improves the recognition rate of the system to abnormal events, and improves the safety of the system. And the system can respond to various traffic events more accurately.

The invention provides a decoupling and Kalman filtering temperature strain demodulation method and system for double fiber gratings, and relates to the technical field of optical fiber sensing. The method comprises the following steps: firstly, designing an FBG sensing module for measuring environment temperature change and strain information; the FBG sensing module comprises a two-channel sensing system composed of an FBG1 sensor and an FBG2 sensor, and is used for measuring environment temperature change and strain information at the same time. Then, aiming at optical signals which are acquired by the two FBG sensors and contain physical quantity information, a wavelength demodulation module is used for acquiring the central wavelength drift distance of reflection spectrums of the two FBG sensors; temperature sensitivity coefficients and strain sensitivity coefficients of the two FBG sensors are obtained, and a linear equation set is constructed for independent variation of temperature and strain to perform matrix decoupling so as to distinguish the influence of the temperature and the strain on the change of the central wavelength; and performing optimization estimation on the decoupled temperature and strain by using the prior information of the temperature and the strain and combining a real-time measurement value by adopting a Kalman filtering method.

The invention discloses a dam leakage monitoring system and method based on optical fiber sensing and time-space fusion. The dam leakage monitoring system comprises an optical fiber sensing system, a data processing and analyzing system, a dam leakage data management system and a real-time monitoring platform. According to the invention, the distributed optical fiber realizes continuous strain and temperature monitoring of the whole length of a dam, a leakage area can be roughly positioned, an FBG sensor is deployed at a key position, local tiny deformation is accurately monitored, a cooperative mode is formed by combining wide-area screening of the distributed optical fiber and key diagnosis of the FBG, and the monitoring efficiency is improved; the all-fiber passive design is adopted, the environmental adaptability is high, the anti-interference performance and the long-term stability are high, frequent maintenance is not needed after the fiber is embedded into the structure, and the operation and maintenance cost is reduced; finally, the leakage risk is displayed through a trend curve of a visual data platform, alarm pushing and emergency plan functions are automatically triggered, the closed-loop time of monitoring, decision making and response is shortened, and the real-time performance and decision-making force are improved.

A fiber optic distributed sensing system and method. The fiber optic distributed sensing system includes: an optical fiber extending through an underwater gas field; an interrogator connected to the optical fiber so that light transmitted through the optical fiber is capable of being sensed by the interrogator; and a computer system configured to obtain sensor data captured by the interrogator and determine an amount or a characteristic of gas within the underwater gas field based on the sensor data. The method includes: capturing sensor data using a fiber optic distributed sensor extending through an acoustic field; performing a wavelet transform on the sensor data in order to obtain spatiotemporal data; and matching the spatiotemporal data to an event template of a predetermined set of event templates in order to identify a spatiotemporal event.

The invention discloses a multi-turn memory optomagnetic encoder hybrid system, belongs to the technical field of position and angle measurement encoders, and aims at solving the problems that an existing optomagnetic hybrid encoder is complex in signal processing, long in axial length, insufficient in precision stability and prone to losing the number of turns and the position. The system comprises an optical encoder, a gallium arsenide magnetic signal acquisition sensor, a multi-antipode unequal magnetic ring, a processor, a hardware circuit, an ultra-low power consumption circuit, a signal acquisition module, a signal processing module and the like, integrates self-developed magnetic angle analysis, turn number memory correction and other algorithms, and adopts dual-redundancy design and intelligent signal mode switching. The method simplifies the signal processing flow, shortens the axial length, improves the measurement precision and stability, enhances the environmental adaptability and fault-tolerant capability, prolongs the endurance, and is suitable for the position angle measurement in a high-precision and severe environment.

The invention relates to the technical field of optical fiber sensing, and discloses an anti-aliasing filtering method and device for a distributed optical fiber acoustic sensing system.The method comprises the steps that environmental noise frequency band characteristics are analyzed in real time, the cut-off frequency and type of an anti-aliasing filter are dynamically adjusted, an invalid sampling channel is closed in combination with frequency-band-division energy detection, and therefore the anti-aliasing filtering efficiency is improved; aliasing noise is significantly suppressed; and the data volume is reduced. And an equipment fault feature library matching mechanism is further introduced, and an emergency anti-aliasing mode is triggered when fault noise suddenly occurs, so that the fault detection accuracy is improved. The method can be widely applied to the fields of oil and gas pipeline monitoring, industrial equipment health diagnosis and the like, and the performance bottleneck of a traditional fixed filter under broadband dynamic noise is solved.

The invention discloses a time-space monitoring method for fracture of an overlying strata mine earthquake key layer in a coal mine, which is characterized in that the DAS technology can realize accurate sensing of underground tiny vibration by measuring the change of sound wave signals in optical fibers, and preliminarily determines the position range of the key layer by analyzing the characteristics of vibration data at the key layer; and meanwhile, high-precision strain data can be provided by utilizing a DSS technology, the position range of the key layer is determined by analyzing the characteristics of the strain data at the key layer, and finally the key layer and the key layer are mutually verified to take an overlapped part and finally accurately position the key layer. After the key layer is positioned, follow-up monitoring is continuously carried out, if new fracture occurs in the key layer, whether the fracture occurs can be judged through vibration data obtained by the DAS host and strain data obtained by the DSS host, the vibration data and the strain data are synchronously subjected to data analysis and judgment and combined analysis, the monitoring precision of the fracture of the key layer is further improved, and the monitoring accuracy of the fracture of the key layer is improved. Therefore, the safety of coal mining is effectively ensured.

The invention relates to the field of optical fiber optics, in particular to a distributed optical fiber temperature measurement system based on Raman scattering, which comprises an optical signal excitation and separation module, a signal acquisition and preprocessing module, a temperature resolving module, a calibration and correction module, a real-time monitoring and early warning module and a management database, the system performs digital accumulation noise reduction on scattering signals through separation of Stokes light and anti-Stokes light, real-time monitoring of optical power and division of spatial positions, generates a temperature distribution curve through temperature calculation and determination of the spatial positions corresponding to the temperatures, generates calibration coefficients through selection of constant-temperature reference points and fitting of a temperature deviation curve, and performs calibration on the scattering signals. The temperature is corrected, a calibration curve is calibrated, meanwhile, light intensity attenuation is compensated, and the light temperature can be accurately measured and early warning can be carried out in time by setting multi-stage temperature early warning threshold values and monitoring temperature abnormal points.

The invention relates to an intelligent permeation grouting process and device for concrete crack self-repairing. The intelligent permeation grouting process and device are suitable for crack detection and repairing of a newly-built concrete structure. The device comprises a blood vessel network embedded into concrete, a crack detection sensor, a control module, a pumping module and a self-repairing material storage module, and automatic detection and repairing of cracks are achieved. The technological process comprises crack detection, data analysis, grouting parameter determination, material injection and repair monitoring. Through the automation and intelligence technology, the repairing efficiency and precision are remarkably improved, and the device is suitable for large structures such as bridges and tunnels.

The invention discloses an array type optical fiber ultrasonic imaging system based on multi-path delay parallel detection, and belongs to the technical field of ultrasonic detection and imaging. The main working process of the system is as follows: continuous laser output by a laser is modulated into pulse laser to be transmitted to an optical fiber ultrasonic detector array, and ultrasonic waves emitted by an ultrasonic wave generating device act on each detection array element to cause the property change of a detection optical signal; through multi-path time delay with the optical fiber as the medium, the detection optical signal forms different transmission time in each channel, is distinguished in a time division mode and is combined into a single path to be output. After photoelectric conversion, electric signals containing multi-channel detection information are collected in parallel, the signals are analyzed at a terminal processor by means of an imaging algorithm with an array parallel architecture, information of a to-be-detected target is obtained, and image reconstruction is completed. The array type optical fiber ultrasonic imaging system has the advantages of being accurate and rapid in scanning detection, simple and compact in system structure and efficient and high-quality in image reconstruction, and large-scale and low-cost array type optical fiber ultrasonic imaging is achieved.

The invention relates to the technical field of sensors, and provides a grating position sensor. A scanning assembly and a light source module are relatively fixed, and an incident diaphragm and an increment detector are arranged in the scanning assembly; the increment detector is spatially divided into at least two first detector regions for detecting a first phase increment signal component and at least two second detector regions for detecting a second phase increment signal component, and the at least two first detector regions are spatially separated from each other; performing redundant detection on the first phase increment signal component; the at least two second detector areas are separated from each other in space so as to perform redundancy detection on the second phase increment signal component; the position metering element is suitable for being fixed on a measured object or a measuring datum plane and can generate relative displacement with the scanning assembly. The invention provides a grating position sensor with strong anti-pollution capability. The grating position sensor can keep a high-reliability working state for a long time in a complex or severe industrial environment.

The invention provides a three-loop control lithium ion battery flexible fast charging method and system, and the method comprises the steps: obtaining the current charging current and voltage of a lithium ion battery, calculating the overpotential through an electrochemical-thermal-aging coupling model, carrying out the constant overpotential lossless charging, and obtaining a preliminary control current; performing constant strain charging according to the initial control current in combination with the obtained internal strain of the lithium ion battery, and limiting the charging current in the stage by taking the expansion strain when the residual electric quantity is set as a strain boundary in the charging process; performing constant-temperature charging according to the charging current in combination with the obtained temperature of the lithium ion battery, and adjusting the charging current rate within a set temperature range; constant overpotential lossless charging control is used as an outer ring, constant strain charging is used as a middle ring, constant temperature charging is used as an inner ring, a final control current is determined through three-ring control, and flexible fast charging is achieved. According to the invention, a plurality of parameters of the battery can be monitored and controlled, and the contradiction between charging safety and rapidity is solved.

The invention provides a tunable laser source output wavelength adjusting device and method, and the method comprises the steps: starting a tunable laser source, carrying out the preheating, and resetting a motor motion unit; acquiring an initial light-emitting wavelength based on a pre-stored relation curve between the light-emitting wavelength of the laser source and the position of the motor; controlling the output wavelength of the laser source through the coarse tuning parameter of the motor motion unit, traversing the tunable output range of the tunable laser source, and collecting the wavelength position of the reflection peak value of the fiber bragg grating and the corresponding optical power value; according to the reflection peak wavelength position, through voltage regulation and control of stacked piezoelectric ceramics, step scanning is carried out according to a target wavelength, and a laser source output wavelength is dynamically adjusted to obtain a fine scanning wavelength; and judging whether the deviation between the fine scanning wavelength and the target wavelength meets the preset precision or not, if so, locking the output wavelength, otherwise, repeatedly regulating and controlling until the conditions are met. According to the invention, traditional current-wavelength dependence is broken through, and wavelength demodulation is realized through electromechanical collaborative calibration and two-stage scanning.

The invention provides a temperature, strain and acoustic emission measurement method and device based on a tilted fiber bragg grating. The method comprises the following steps: carrying out cladding mode and Ghost mode demodulation on a transmission spectrum of a tilted fiber grating to obtain cladding mode wavelength shift and Ghost mode wavelength shift; wherein the tilted fiber bragg grating is mounted on a target structure; the cladding mode wavelength shift and the Ghost mode wavelength shift are substituted into the two-parameter matrix and solved, and the temperature variation and the strain variation of the target structure are obtained; wherein the two-parameter matrix comprises cladding mode-temperature sensitivity, Ghost mode-temperature sensitivity, cladding mode-strain sensitivity and Ghost mode-strain sensitivity of the tilted fiber bragg grating; and the Bragg reflection spectrum of the tilted fiber grating is demodulated and analyzed to obtain an acoustic emission signal of the target structure. According to the invention, simultaneous measurement of temperature, strain and acoustic emission signals can be realized only by using a single fiber bragg grating.

The invention discloses a kilometer deep well roadway toughness regulation and control supporting system and a dynamic design method, and belongs to the field of deep well roadway supporting. The supporting system comprises a multi-layer collaborative structure and an intelligent regulation and control module, the multi-layer collaborative structure sequentially comprises a shape memory alloy energy absorption layer used for resisting impact loads and a gradient pore foam metal buffer layer used for energy grading dissipation from inside to outside, and the multi-layer collaborative structure is connected with roadway surrounding rock in an anchoring mode through an anchor rod anchoring structure; the intelligent regulation and control module comprises a distributed optical fiber sensor array used for monitoring surrounding environment signals of surrounding rock in real time, an electrostriction driver used for regulating and controlling the rigidity of the multi-layer cooperative structure and a multi-channel data fusion terminal used for achieving underground and surface data transmission synchronization. By the adoption of the kilometer deep well roadway toughness regulation and control supporting system and the dynamic design method, the problems that a traditional supporting mode is too high in material rigidity, lacks dynamic regulation and control capacity and is insufficient in impact toughness can be solved.

The invention discloses a distributed optical fiber sensing positioning system and positioning method based on asymmetric double Mach-Zehnder. The distributed optical fiber sensing positioning system comprises an asymmetric double Mach-Zehnder distributed optical fiber sensing module and a disturbance positioning module. The optical fiber sensing module comprises a first light source, a second light source, an asymmetric double Mach-Zehnder interferometer, a data acquisition card and an industrial personal computer; two beams of light emitted by the first light source and the second light source are respectively propagated clockwise and anticlockwise in a sensing loop, and interfere in couplers at opposite ends in the interferometer to form two paths of interference signals, and the data acquisition card acquires the two paths of interference signals, converts the two paths of interference signals into electric signals, and sends the electric signals to the industrial personal computer for signal processing; the disturbance positioning module is used for obtaining a positioning result, a double-endpoint detection method based on median filtering is adopted in the aspect of endpoint detection, iterative variational mode decomposition is used in the aspect of time-frequency change feature extraction, and envelope extraction and generalized secondary cross-correlation time delay estimation algorithms are used in the aspect of time delay estimation positioning.

An optical frequency domain reflectometer with environmental disturbance resistance and large strain measurement capability belongs to the field of distributed optical fiber sensing and comprises an opposite sweep frequency light frequency modulation continuous wave signal generation module, a light splitting device, a modulation device, a circulator, a polarization controller, an optical coupling device, a photoelectric conversion module and a data acquisition and processing module. An optical signal generated by an opposite sweep frequency light frequency modulation continuous wave signal generation module is divided into probe light and local oscillation light through a light splitting device, the probe light is modulated through a modulation device and sent to an optical fiber through a circulator, and a Rayleigh back scattering light signal generated by the optical fiber and the local oscillation light interfere in an optical coupling device to obtain interference light; the photoelectric conversion module mixes beat frequency signals of interference light, and the data acquisition and processing module analyzes and processes the beat frequency signals. According to the invention, the position information of the Rayleigh backscattering point is marked by using the modulated probe light, the Rayleigh scattering signal at the corresponding position is restored, crosstalk between channels is inhibited, and high-precision measurement in a large dynamic range and resistant to environmental disturbance is realized.

The invention discloses an all-fiber vortex interference system and a phase variation measurement method, belongs to the field of optical precision instrument design and test, and aims to realize ultrahigh-precision phase variation measurement by using an all-fiber structure. The vortex interference system comprises a light source module, an optical fiber beam splitting module, an optical fiber sensing module, an optical fiber mode conversion module, an optical fiber mode interference module and an imaging module in sequence along an optical path. The phase variation measurement method is a phase variation demodulation method based on angular Fourier transform, which is provided for the all-fiber vortex interference system. The interferometer provided by the invention does not need a complicated light path alignment step of a traditional interferometer, and the sensitivity of the all-fiber vortex interferometer is further improved.

The invention provides a temperature and pressure optical fiber sensor, and belongs to the technical field of optical fibers. The sensor is packaged in a shell and comprises a pressure sensitive structure composed of a pressure film, a supporting beam and a fixing base, a fiber bragg grating strain sensor and a fiber bragg grating temperature sensor, the fiber bragg grating strain sensor and the fiber bragg grating temperature sensor share one fiber structure, and the fiber bragg grating strain sensor and the fiber bragg grating temperature sensor are installed on a shaft which is subjected to maximum deformation after the pressure sensitive structure is pressed. The fiber bragg grating strain sensor is located at a first segment of the fiber. The fiber bragg grating temperature sensor is located at a second segment of the fiber. The first section has prestress, and the second section is kept in a relaxed state. Pressure is sensed through the pressure sensitive structure, maximum deformation occurs in the axial direction where the fiber bragg grating strain sensor and the fiber bragg grating temperature sensor are installed, the magnitude of the pressure is reflected through wavelength drift of the fiber bragg grating, temperature is sensed independently through the fiber bragg grating temperature sensor, and temperature compensation is carried out, so that an accurate strain value is obtained. According to the invention, temperature and pressure dual-parameter sensing can be realized.

The invention belongs to the technical field of pavement monitoring methods, and particularly discloses a distributed optical fiber permanent deformation monitoring method for an asphalt pavement under a moving load. The method comprises the following steps: laying a single-mode optical fiber in a test piece; laying a full-bridge strain gauge in the test piece; monitoring an optical fiber vibration signal of the test piece during the movement of a test wheel and a strain change of the test piece during the movement of the test wheel in real time through a strain acquisition instrument; processing the optical fiber vibration signal and the strain change by using matlab data analysis software; analyzing the data change trend according to the processed optical fiber vibration signal and the strain change, and establishing a mathematical relationship between the two; and according to the mathematical relationship, distributed monitoring of the permanent deformation of the asphalt pavement under the moving load by the optical fiber vibration signals is realized. By the adoption of the bituminous pavement distributed optical fiber permanent deformation monitoring method under the moving load, real-time, dynamic, large-range, long-distance and high-precision monitoring of bituminous pavement permanent deformation is achieved, and the defects in the prior art are overcome.

The invention discloses an optical fiber dislocation temperature sensor and a preparation method thereof. The optical fiber dislocation temperature sensor comprises a dislocation optical fiber integrated with a photoresist film layer. The staggered optical fiber integrated with the photoresist film layer comprises a staggered optical fiber and a photoresist film layer covering a staggered area of the staggered optical fiber; the dislocation optical fiber is composed of a first multi-mode optical fiber, a second multi-mode optical fiber and a third multi-mode optical fiber which is welded between the first multi-mode optical fiber and the second multi-mode optical fiber in a dislocation mode. The staggered optical fiber is prepared through the optical fiber melting technology, the staggered area of the staggered optical fiber is coated with the SU-8 photoresist with the high thermo-optical coefficient and the high thermal expansion coefficient to form the photoresist film layer, high-sensitivity temperature sensing detection is achieved, the size is small, the preparation process is simple, and the sensor is suitable for biomedical treatment, medical treatment and the like. Wide application prospects are realized in the fields of aerospace, industry and agriculture and the like.