174 results about "Wavelength shift" patented technology

The invention provides a time division multiplexing multi-parameter synchronous sensing method and system based on a multi-core optical fiber. A multi-core optical fiber containing three heterogeneous fiber cores is embedded into a measured object, and a distributed reflection grating array forming an inclined angle with the axial direction is inscribed on the surface of each fiber core; energy exchange data between modes of all fiber cores and reflection grating wavelength shift signals are synchronously collected by adopting a time division multiplexing technology, phase difference signals are extracted through a cross correlation algorithm to serve as curvature reference values, dynamic compensation operation is carried out on the wavelength shift data and the phase signals, and accurate strain distribution is obtained after temperature interference is effectively eliminated; a coordinate transformation model is established by combining the three-dimensional geometric parameters of the spiral optical fiber, vector synthesis is performed on the curvature reference and the strain parameters, and accurate reconstruction of the three-dimensional deformation field of the measured object is realized. According to the technical scheme provided by the invention, through multi-core fiber multi-parameter synchronous sensing and three-dimensional coordinate mapping, temperature self-compensation high-precision three-dimensional deformation field real-time reconstruction is realized.

The invention discloses a temperature control and noise reduction method for an analog optical module, and relates to the technical field of data processing. The method comprises the following steps: collecting and preprocessing an original temperature signal, environment temperature time sequence data and an optical wavelength original detection value of an optical module; improving the LSTM model, constructing a junction temperature dynamic prediction model, and outputting prediction data; a pre-trained BP neural network is utilized to calculate the temperature compensation amount according to the real-time wavelength offset, and a PPO reinforcement learning algorithm is adopted to optimize with the temperature stability, the wavelength offset and the TEC power consumption as multiple targets to obtain an optimal PID parameter mapping table; and finally, predicting, compensating and optimizing parameters are fused, and control output for driving the TEC is generated through a multi-mode intelligent decision. The problems of insufficient control precision and response lag are effectively solved, cooperative high-precision control over the junction temperature and the emission wavelength of the laser is achieved, transmission noise is remarkably reduced, and meanwhile system energy consumption and the self-adaptive capacity are considered.

The invention discloses a battery evaluation computer system and method based on multi-modal characteristics, and belongs to the technical field of battery health management, and the system mainly comprises a multi-modal sensing module, specifically a grating sensor unit, which is used for collecting surface and internal deformation data of a battery, including wavelength offset (delta lambda), strain (epsilon) and deformation characteristics after temperature compensation; the electrochemical sensor unit is used for acquiring voltage, current, internal resistance and temperature data of the battery; and the acoustic sensor unit is used for detecting ultrasonic signals of gas separation or structure abnormity in the battery. By integrating the fiber grating sensor, the electrochemical sensor and the acoustic sensor, deformation, voltage / current, temperature and acoustic signals of the battery are acquired in real time, and high-precision battery state of health (SOH) evaluation and residual life (RUL) prediction are realized in combination with multi-modal data processing and an intelligent algorithm.

The invention relates to a method and a system for detecting the concentration of trace methane by locking the position of an absorption peak, and belongs to the technical field of laser gas detection. Modulated laser output by a laser is divided into two paths, one path enters a reference light path, the other path firstly passes through a gas absorption cell and then enters an actual detection light path, and methane gas with known concentration is sealed in the reference light path; demodulating a modulation signal output by the actual detection light path, and calculating to obtain a trace methane gas concentration value; and demodulating the modulation signal output by the reference light path to obtain a second harmonic signal, comparing the amplitude of the second harmonic signal with the amplitude of a harmonic signal corresponding to a preset methane absorption peak to generate a wavelength shift error signal, and adjusting the driving parameter of the laser through a feedback mechanism to generate a wavelength shift error signal. The output power and wavelength drift of the laser are monitored in real time, and it is ensured that the laser wavelength is always locked within the methane absorption peak range. According to the invention, high-precision and high-stability trace methane concentration detection can be realized.

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 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 provides a water-cooled wall safety monitoring method and a combustion adjustment control method based on distributed optical fiber sensing, and the method specifically comprises the following steps: arranging a Bragg grating on a water-cooled wall, and obtaining the Bragg wavelength offset; predicting a temperature value and a strain value at the current moment according to historical temperature and strain data by using a state equation of stress and temperature; the Bragg wavelength prediction offset is obtained by combining the temperature value and the strain value at the current moment with the sensor error; obtaining a wavelength change residual error according to the Bragg wavelength offset and the Bragg wavelength prediction offset, and correcting the temperature value and the strain value at the current moment by using the wavelength change residual error to obtain a real temperature value and a real strain value at the current moment; a real strain value at the current moment is converted into a stress value, a water-cooled wall tearing factor is established by utilizing the stress value, the number of thermal cycles and the fatigue life of a water-cooled wall material, water-cooled wall safety monitoring and combustion adjustment control are realized by utilizing the water-cooled wall tearing factor, and the operation safety of the boiler is improved.

The invention discloses a method for measuring fan blade root stress based on a fiber bragg grating sensor. According to the method, 6-10 key measurement points are selected in a blade root area of a fan blade, a pair of FBG sensors is installed at each measurement point, one FBG sensor is used for stress measurement (affected by strain and temperature at the same time), the other FBG sensor is used for temperature compensation, and decoupling of temperature and strain signals is achieved. The system adopts a single-mode optical fiber, a broadband light source (the wave band is 1525-1565 nm, and the power is 10-20 mW) and a high-resolution spectrum analyzer (the resolution is smaller than or equal to 1 pm, and the sampling rate is larger than or equal to 100 Hz or 1 kHz) to collect optical signals reflected by an FBG sensor in real time, measured wavelength shift is converted into accurate strain data through temperature compensation and a strain calculation formula, and the optical signals are transmitted to the FBG sensor. And calculating a stress value by combining the Young modulus and Poisson's ratio of the material. The method has the advantages of being high in precision, high in real-time performance, resistant to electromagnetic interference and suitable for seaborne, high-altitude and other severe environments, and reliable data support can be provided for dynamic stress monitoring, fatigue life prediction and fault early warning of the fan blade.

The invention discloses an optical fiber twinning controllable vernier hydrogen sensor and a detection method, and belongs to the technical field of optical fiber sensing, the optical fiber twinning controllable vernier hydrogen sensor comprises a single-mode optical fiber, a femtosecond laser direct writing grating, a Fabry-Perot interferometer and a Pd / WO3 hydrogen sensitive film; the single-mode optical fiber comprises an optical fiber core and an optical fiber cladding, the femtosecond laser direct writing grating is prepared in the optical fiber core, the Fabry-Perot interferometer is composed of a reflecting surface 1 and a reflecting surface 2 which are relatively parallel to each other, the Pd / WO3 hydrogen sensitive film is coated on the inner side of the reflecting surface 2, and the femtosecond laser direct writing grating and the Fabry-Perot interferometer are arranged in series; the optical path of the Fabry-Perot interferometer is modulated through the interaction of the Pd / WO3 hydrogen sensitive film and hydrogen, interference spectrum wavelength drift is triggered, temperature compensation is achieved in combination with the temperature response of the femtosecond laser direct writing grating, and hydrogen concentration sensing is completed. The method is suitable for hydrogen leakage detection in industrial environments, energy equipment and other scenes.

The invention provides an inter-channel crosstalk suppression method in a multi-channel optical module, which aims at the problems of inter-channel interference and signal overlapping caused by wavelength shift in the multi-channel optical module, calculates the wavelength shift by adopting a proportional integral differential control method through collecting the reading of a temperature sensor and the output wavelength data of a laser device in real time, and finally suppresses the crosstalk in the multi-channel optical module. The threshold value is dynamically adjusted in combination with the environment temperature change, and the interference risk index is quantified; the wavelength drift trend is extracted through time sequence analysis, the channel interval adjustment logic is optimized, the filter bank is dynamically configured to improve the signal purity, meanwhile, the wavelength parameter is corrected through the offset compensation value, and the stability is ensured. If the transmission quality requirement is met, configuration parameters are locked, a correction model is matched and optimized through historical data, potential risks are predicted in combination with state estimation filtering, and the logic adaptability is enhanced and adjusted. According to the invention, efficient correction of wavelength drift and interference minimization are finally realized, and the transmission quality and operation stability of the multi-channel optical module are improved.

The invention relates to the technical field of optical fiber sensing, and discloses a stress monitoring and temperature measuring method and system based on a fiber grating. According to the method, a historical stress temperature data set is inquired and determined in a historical storage unit by obtaining identification information of a target fiber grating sensor; performing grouping operation on the historical stress temperature data set to generate a plurality of grouped monitoring data sets; extracting wavelength shift features for each grouped monitoring data set to obtain a plurality of feature core values and feature influence ranges; establishing a plurality of analysis units by using the feature influence range, and processing the optical signal sequence captured in real time by using the analysis units to generate a plurality of analysis feature sets; and integrating the analytic feature set to obtain an integrated feature result, and further deriving a stress measurement value and a temperature measurement value based on the result. The method improves the effectiveness and reliability of the fiber bragg grating in stress and temperature monitoring, and is suitable for related measurement scenes in the fields of engineering structure health monitoring, industrial process control and the like.

The invention belongs to the technical field of temperature demodulation, and particularly relates to a temperature measurement method and device based on machine learning and a storage medium, and the method comprises the steps: converting the temperature change into the wavelength shift of an interference spectrum through an interference type optical fiber temperature sensor; performing time domain stretching on the wavelength offset by using the dispersion compensation optical fiber to obtain time sequence offset; the method comprises the following steps: acquiring time sequence offset through signal acquisition equipment to obtain time domain sequence data, and preprocessing the time domain sequence data; position coding is adopted to obtain a feature sequence containing time sequence information; inputting the feature sequence into a Transform neural network to extract global features; normalizing the global features and then enhancing the global features; and mapping the enhanced features through a full connection layer of the Transform neural network, and outputting a predicted temperature value. And high-speed and high-precision temperature prediction is realized.

The invention belongs to the related technical field of sensors, and provides a multi-parameter integrated acquisition optical fiber sensor and a monitoring system thereof in order to solve the problem that high-precision monitoring of a static signal and a dynamic signal is difficult to consider by an existing sensor at the same time, a sensing cavity is sequentially divided into a static signal sensing area and a dynamic signal sensing area in the axial direction; the static signal sensing area adopts a multi-core fiber, fiber gratings are respectively engraved on the multi-core fiber, and the wavelength demodulation of the static signal is realized through the central wavelength drift distance of the fiber gratings; the dynamic signal sensing area is provided with a dynamic signal sensing unit, the dynamic signal sensing unit comprises F-P air microcavities formed between the dynamic signal sensing unit and the end faces of all fiber cores of the multi-core optical fiber, and intensity demodulation of dynamic signals is achieved through cavity length changes of the F-P air microcavities. According to the invention, a wavelength modulation and intensity modulation parallel composite demodulation mechanism is adopted, and decoupling acquisition of static strain, temperature and dynamic vibration is realized in a single sensor.

The invention provides a multi-point distributed temperature detection method and system based on a multi-core optical fiber structure. Wherein grating array etching processing is carried out on at least three fiber cores to form a specific reflection wavelength interval; when an external light source is incident, the fiber core grating structures reflect optical signals with corresponding wavelengths to generate reflected optical signals with different wavebands; the method comprises the following steps: dividing a reflected light signal channel through a wavelength branching device, generating independent channel signals of each fiber core, and simultaneously carrying out time sequence separation on multi-grating signals in the same fiber core to obtain reflected signals in discrete time sequence distribution; combining the independent channel signal with the discrete reflection signal, performing interference comparison with the fixed wavelength reference optical signal, generating a phase difference interference signal reflecting wavelength shift, and analyzing the wavelength shift to obtain temperature-related wavelength shift data; and through analysis and stress error elimination under deformation constraint, outputting a temperature detection result. According to the technical scheme provided by the invention, the accuracy of distributed temperature detection is improved.

The invention provides a multi-core optical fiber strain and temperature decoupling method and system for grating demodulation, electronic equipment and a storage medium, and relates to the technical field of optical fiber sensing, and the method comprises the steps: obtaining the lowest wavelength data of the spectrum of fiber cores at two sides of an air layer of a multi-core optical fiber, and recording the position data of a light spot formed by the secondary dispersion of a diffraction grating at the same time. The diffraction grating is used for secondary light splitting of the composite light, independent spectrum data are generated, and two-core coupling is blocked through an air layer. A double-task analysis network is constructed, strain wavelength offset is obtained through strain branches, and temperature wavelength correction is obtained through temperature branches. Network weight is adjusted in combination with related data to generate a strain demodulation value of temperature decoupling, the strain demodulation value is converted into a standardized signal to be transmitted to a monitoring system, an axial strain dynamic distribution diagram is reconstructed, a temperature compensation curve is synchronously displayed, multi-core optical fiber strain and temperature accurate decoupling can be achieved, strain information can be dynamically obtained, and the distribution and compensation state can be synchronously displayed.

A sensor network comprises at least one lateral optical fiber and at least one longitudinal optical fiber. The lateral fiber comprises optical sensors coupled to a pavement in a transverse orientation relative to a direction of vehicle travel along the pavement. The longitudinal fiber comprises optical sensors coupled to the pavement in a longitudinal orientation relative to the direction of vehicle travel. The optical sensors are configured to produce wavelength shift signals comprising one or more lateral strain signals associated with the lateral fiber and one or more tangential strain signals associated with the longitudinal fiber. A processor is operatively coupled to the sensor network and configured to determine a weight of vehicles moving along the pavement based on the lateral and tangential strain signals. A transmitter is operatively coupled to the processor and configured to transmit the weight of vehicles to a predetermined location.

The invention provides a real-time multi-mode emergency patient treatment path intelligent matching method, an electronic device and a storage medium, and the method comprises the steps: obtaining the micro-strain wavelength offset and body surface pressure data of an intelligent textile in a body position movement process of a trauma patient in real time through an embedded fiber Bragg grating sensor; in combination with multi-axis acceleration data acquired by a multi-axis acceleration sensor on the transfer stretcher, generating a body surface pressure gradient distribution thermodynamic diagram; determining the position of a wound surface and extracting taboo bumping spectrum features; generating an initial candidate path set based on the bump frequency forbidden zone and a road roughness label in the electronic map, and screening out an optimal navigation path according to a turning centrifugal force threshold value; the moving speed of the transfer vehicle is obtained in real time through the vehicle-mounted positioning module, the transmission channel bandwidth of the preset broadcast channel is dynamically adjusted, and the optimal navigation path is sent to other terminals. According to the invention, the accuracy and real-time performance of the transfer path planning of the traumatic patient are improved.

The invention provides a super-large-span net rack deformation monitoring method, and belongs to the technical field of deformation monitoring. A shape sensor is installed on a key rod piece of a super-large-span net rack in a wind tunnel test section, a double-grating differential compensation system suitable for a wind tunnel environment is established, and wavelength drift caused by high-speed airflow, temperature shock and pressure fluctuation is eliminated; a wavelength division multiplexing technology is adopted to carry out anti-interference signal acquisition, a double-layer game optimization model considering wind tunnel working condition characteristics is constructed to carry out dynamic error compensation, and a grating strain response matrix is established to realize accurate conversion from strain to deformation in a wind tunnel environment. A time sequence model based on a wind tunnel operation cycle is adopted to predict the wavelength drift trend of the sensor and start an adaptive compensation mechanism, and the technical problem that the deformation monitoring precision is seriously reduced due to wavelength drift of a wind tunnel test section ultra-large span grid structure under the action of high-speed airflow is solved.

The invention discloses a high-temperature-resistant passive strain gauge for gas turbine blade monitoring and a preparation method and application thereof, and belongs to the technical field of gas turbine health monitoring. The high-temperature-resistant passive strain gauge comprises a strain gauge substrate, an insulating layer, a snakelike sensitive grid, a fiber bragg grating (FBG) and a yttria-stabilized zirconia (YSZ) protective layer. The strain gauge has the beneficial effects that aiming at the limitation of a traditional sensor in a high-temperature (greater than or equal to 1200 DEG C), high-frequency vibration and corrosion environment, the strain gauge adopts the high-temperature-resistant platinum-tungsten alloy snakelike sensitive grid, the single crystal aluminum oxide ceramic substrate and the sapphire fiber bragg grating to transmit a strain signal through wavelength shift, and an external power supply is not needed; and the Ir-Re alloy is brazed and fixed to the microgroove in the surface of the blade, the shearing strength is high, and the service life is long. The method overcomes the technical bottleneck of strain measurement in a high-temperature environment, is suitable for scenes of aero-engines, gas turbine blades and the like, and remarkably reduces the maintenance cost and improves the monitoring reliability.

The invention discloses an intelligent regulation and control method and system for anchoring force of a freight cableway in a complex stratum, and relates to the technical field of cableway engineering, and the method comprises the following steps: carrying out the temperature decoupling of a wavelength offset through a self-calibration temperature decoupling method, and obtaining an actual strain value and a strain value confidence coefficient; the wavelength offset is extracted from the obtained anchor rod multi-source data set; based on the actual strain value and the multi-source data set of the anchor rod, axial force distribution serves as a solving target, and axial force data of the anchor rod are obtained through a physical constraint inversion method; axial force data is predicted in real time through a Bayesian algorithm, and a compensation regulation and control instruction is generated according to the evolution trend of the predicted axial force data. The method is used for solving the problems that the axial force prediction result is not accurate due to temperature interference and the anchoring force regulation and control means are lagged.

The invention discloses a hydrogen sensor based on a fiber bragg grating. An optical fiber core part of a sensing optical fiber is a circular cross section and is divided into two half parts, a first Bragg grating and a second Bragg grating with different grating periods are respectively engraved, an optical fiber cladding is D-shaped, and a hydrogen-sensitive coating is arranged on a flat peripheral surface. The inner diameter of the capillary tube is 0.8-1.2 mm, the outer diameter of the capillary tube is 4-6mm, the side wall of the capillary tube is provided with a hydrogen inlet / outlet through hole, and the sensing optical fiber is fixed on the inner wall of the capillary tube and is The sensor inner shell is provided with a first hydrogen inlet and a first hydrogen outlet, and a filter screen is arranged at the inlet and forms a hydrogen inlet and outlet channel together with the sensor outer shell. The sensor utilizes the hydrogen-sensitive coating to adsorb hydrogen and expand, so that the optical fiber core part is strained, and the central wavelength of reflected light of the Bragg grating shifts to detect the hydrogen concentration. The sensor has the advantages of strong electromagnetic interference resistance, high sensitivity, good stability, fast response and the like, and can be widely applied to concentration monitoring of hydrogen related production, storage, transportation and other scenes.

This invention discloses a battery temperature and strain detection device and battery pack, relating to the field of battery monitoring technology. The device includes a light source, a controller, and a detection optical fiber. The detection optical fiber is connected between the light source and the controller to receive and transmit light to the controller. The controller is configured to determine a first wavelength shift caused by temperature influence when light flows through a fiber optic grating in the detection optical fiber, and a second wavelength shift caused by strain influence when light flows through a photonic crystal fiber in the detection optical fiber. Based on the first and second wavelength shifts, and the temperature and strain sensitivity coefficients of the fiber optic grating and the photonic crystal fiber, the temperature change and strain change of the battery are determined. Based on the temperature change, strain change, and preset temperature and strain reference values, the battery temperature and strain values ​​are determined. This solution improves the ability to detect battery temperature and strain.

The invention relates to a strain detection method and system, electronic equipment and a medium, and belongs to the technical field of optical fiber sensing, and the method comprises the steps: carrying out the linear fitting of a first central wavelength drift distance of a temperature sensing optical cable and a strain sensing optical cable which are laid in parallel in a first time window, and obtaining a ratio of the temperature sensitivity coefficients of the two optical cables; acquiring the actual strain of the strain sensing optical cable in a second time window, a second central wavelength drift distance and a third central wavelength drift distance of the temperature sensing optical cable; the product of the ratio and the third central wavelength drift distance is subtracted from the second central wavelength drift distance, and the strain-induced central wavelength drift distance of the strain sensing optical cable is obtained; performing linear fitting on the actual strain and the strain-induced central wavelength drift distance to obtain a strain sensitivity coefficient of the strain sensing optical cable; and performing strain detection based on the ratio and the strain sensitivity coefficient through the strain sensing optical cable. The temperature or strain sensitivity coefficient does not need to be calibrated in advance, and the practicability is higher.

The application belongs to the technical field of temperature demodulation, and particularly relates to a temperature measuring method and device based on machine learning and a storage medium, the method comprising: converting temperature changes into wavelength shifts of an interference spectrum by an interference optical fiber temperature sensor; stretching the wavelength shifts in the time domain by using a dispersion compensation optical fiber to obtain time sequence shifts; collecting the time sequence shifts by a signal acquisition device to obtain time domain sequence data, and preprocessing the time domain sequence data; obtaining a feature sequence containing time sequence information by using position coding; inputting the feature sequence into a Transform neural network to extract global features; enhancing the global features after normalization; and mapping the enhanced features by a full connection layer of the Transform neural network to output a predicted temperature value. High-speed and high-precision temperature prediction is realized.

The present application provides a time-division multiplexing multi-parameter synchronous sensing method and system based on multi-core optical fiber. Among them, a multi-core optical fiber containing three heterogeneous cores is embedded in the measured object, and a distributed reflection grating array with an inclination angle to the axial direction is inscribed on the surface of each core; the time-division multiplexing technology is used to synchronously collect the inter-mode energy exchange data and the reflection grating wavelength shift signals of each core, and the cross-correlation algorithm is used to extract the phase difference signal as the curvature reference value, and the wavelength shift data and the phase signal are subjected to dynamic compensation operation to effectively eliminate the temperature interference and obtain the accurate strain distribution; a coordinate transformation model is established by combining the three-dimensional geometric parameters of the helical optical fiber, and the curvature reference and the strain parameters are vectorially synthesized to realize the accurate reconstruction of the three-dimensional deformation field of the measured object. The technical solution provided by the present application realizes the real-time reconstruction of a high-precision three-dimensional deformation field with temperature self-compensation through multi-core optical fiber multi-parameter synchronous sensing and three-dimensional coordinate mapping.

Disclosed is a pulsed laser apparatus and method of generating a laser pulse. The apparatus includes an input coupler configured to receive pumping light from a pumping light source and a seed pulse from a seed pulse generator. The apparatus further includes a doped fiber-optic cable with an input port at a first end configured to receive the pumping light and the seed pulse. The doped fiber-optic cable amplifies the seed pulse to generate an output pulse. Along a first length of the doped fiber optic cable, the pulse spectrum broadens rapidly owing to nonlinearity. Beyond the first length in an extended portion, the output pulse shifts towards longer wavelengths and broadens in both spectral and temporal domains. The apparatus also includes an output port at a second end of the doped fiber-optic cable, wherein the output pulse exits the doped fiber-optic cable at the output port.

The demodulation method based on the ultra-weak fiber grating OFDR includes: performing fast Fourier transform on the time domain reflection signal collected by the OFDR system to obtain a frequency domain spectrum; setting an amplitude threshold, identifying the UW-FBG array reflection peak in the frequency domain spectrum, calibrating the spatial position of the sensing unit, and intercepting the window segment spectrum signal corresponding to each UW-FBG; performing inverse Fourier transform on the intercepted window segment spectrum signal to restore the spectrum signal of a single UW-FBG; for the reconstructed spectrum signal, selecting a fitting region containing the Bragg reflection peak, iteratively optimizing the Gaussian function fitting parameters by the least square method, and demodulating the peak Bragg wavelength; traversing the window segment spectrum signals of all UW-FBGs and repeating the above steps to obtain the Bragg wavelength shift distribution of the whole sensing region. The demodulation method based on the ultra-weak fiber grating OFDR improves the high-precision detection characteristics of the OFDR, realizes dynamic demodulation, significantly improves the sensing demodulation rate, and simplifies the algorithm complexity.

The application relates to the technical field of gas flow detection, and discloses a fiber grating temperature drift compensation method and device. The method comprises the following steps: acquiring grating wavelength offset and quantum dot fluorescence intensity; querying a pre-calibrated temperature-fluorescence intensity-strain mapping table based on the fluorescence intensity, and dynamically matching a strain compensation coefficient corresponding to the current temperature; adopting a nonlinear correction algorithm to separate a parasitic strain component caused by the temperature, and outputting a calibrated wavelength offset; and combining a strain-flow model to calculate an accurate flow value. Based on the above scheme, the strain measurement precision and the anti-interference ability of the fiber grating in a temperature fluctuation environment are significantly improved.

The application discloses a kind of machine room equipment intelligent remote operation and maintenance method and platform, it is related to intelligent operation and maintenance technical field, including, construct bayesian probability model, and combine optical signal characteristics and current harmonic characteristics, predict the failure probability distribution of machine room equipment;According to the failure probability distribution of machine room equipment, convert fault coordinates into equipment logical identifier, and detect the quantum teleportation link of machine room equipment, generate machine room equipment switching instruction according to detection result;According to machine room equipment switching instruction, send Bell state measurement command to fault equipment, and carry out quantum state reconstruction and machine room equipment switching.The application constructs multilayer bayesian probability model based on Gaussian distribution, Granger causality test and variational inference, realizes the nonlinear correlation analysis of optical signal wavelength shift and current harmonic characteristics, can accurately capture the weak signs of potential equipment failure, to significantly improve the sensitivity and reliability of failure prediction.

The embodiment of the invention discloses a laser device and a preparation method, the laser device comprises a laser device body, a connecting piece and a deformation compensation module, the deformation compensation module is connected to a grating of the laser device body through the connecting piece, and based on this, in the use process of the laser device, deformation is generated through heating or cooling of the deformation compensation module; and then a mechanical linkage design is formed by using a connecting piece, so that the position of the grating can be adjusted, the resonant cavity length of the laser can be adjusted, self-adjustment of the cavity length of the laser can be realized, wavelength stability passive control is realized, power consumption and cost are reduced, and a temperature control system is effectively simplified. And meanwhile, wavelength shift caused by temperature change of the semiconductor laser in a working state can be effectively adjusted, the stability of the wavelength of the semiconductor laser is maintained, and a thermoelectric refrigerating unit in the traditional technology is replaced to meet the miniaturization requirement of the LD laser.