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972 results about "Frequency shift" patented technology

Unmanned aerial vehicle autonomous decision reinforcement learning method, system and device based on multi-objective optimization, and storage medium

The invention relates to the technical field of unmanned aerial vehicle autonomous decision, provides an unmanned aerial vehicle autonomous decision reinforcement learning method, system and device based on multi-objective optimization, and a storage medium, and solves the problems of limited dynamic task distribution capability and poor decision capability of an unmanned aerial vehicle. The method comprises the steps that based on infrared data and radar data, a moving track prediction sequence of a suspicious target in a target area is generated, a moving probability thermodynamic diagram is constructed, and the target area comprises a patrolled area; performing Doppler frequency shift analysis on the radar data to generate a target velocity vector field; and in combination with the position data of the unmanned aerial vehicle, outputting an unmanned aerial vehicle autonomous decision reinforcement learning result of a dynamic segmentation scheme containing an unpatrolled region through a region re-division reinforcement learning model based on a reward function for multi-objective optimization. The reward function is used for reflecting area coverage rate maximization, target tracking success probability maximization and path energy consumption minimization. According to the invention, autonomous intelligent decision-making of the unmanned aerial vehicle on the unpatrolled area is realized.
Owner:ZHUHAI XIANG YI AVIATION TECH CO LTD

Mountain tunnel surrounding rock deformation monitoring method and system based on distributed optical fiber sensing

The invention relates to the technical field of deformation monitoring, in particular to a mountain tunnel surrounding rock deformation monitoring method and system based on distributed optical fiber sensing. The method comprises the following steps that Brillouin frequency shift original data and center wavelength original data are collected, tunnel construction progress data and surrounding rock geological survey data are obtained at the same time, format standardization and time sequence alignment processing is carried out, and preprocessed optical fiber sensing basic data, construction time sequence data and geological attribute data are generated; surrounding rock deformation characteristic parameters are extracted based on the optical fiber sensing basic data, and surrounding rock deformation multi-dimensional characteristic vectors are constructed; performing deformation mode density clustering and surrounding rock deformation dynamic prediction based on the surrounding rock deformation multi-dimensional feature vector to generate a surrounding rock deformation dynamic prediction value; and carrying out comparison and iterative correction on the dynamic prediction values of the surrounding rock deformation, and carrying out regionalized polymerization to generate a mountain tunnel surrounding rock deformation spatial and temporal distribution visualization result. According to the invention, full-time-space accurate monitoring and early warning of tunnel surrounding rock deformation can be realized.
Owner:中铁长江交通设计集团有限公司

Steel structure stress monitoring method based on distributed optical fiber sensing

The invention relates to the technical field of structural stress precision measurement, in particular to a distributed optical fiber sensing-based steel structure stress monitoring method, which comprises the following steps of: 1, constructing a sensing optical fiber array in a steel structure node area; 2, injecting optical pulses into the sensing optical fiber array, and synchronously collecting Brillouin frequency shift signals and Raman scattering signals of all points; 3, temperature and mechanical strain are separated based on the reference optical fiber signals, global temperature compensation is adopted for the first optical fiber set, and temperature gradient compensation along the optical fiber path is adopted for the second optical fiber set; 4, decomposing the compensated mechanical strain into multidirectional strain components according to the spatial orientation of the optical fiber, and reconstructing a three-dimensional stress field through strain component fusion; and 5, dynamically judging the damage risk according to the local stress concentration coefficient and the change rate thereof in the stress field. And through the temperature compensation technology, the influence of the environment temperature change on the strain data is eliminated, and the reliability of the monitoring result is improved.
Owner:WEIFANG AOKEDU STEEL STRUCTURE ENGINEERING CO LTD

Fringe projection three-dimensional shape measurement method based on frequency domain and time domain joint coding

PendingCN121026011AUsing optical means3D modellingTime domainSubsurface scattering
The invention discloses a fringe projection three-dimensional shape measurement method based on frequency domain and time domain joint coding, and the method comprises the following steps: firstly, embedding a multi-frequency three-step phase shift fringe pattern in the vertical direction based on multi-scale region division, introducing four-step phase shift and complementary Gray code joint coding in the horizontal direction, generating a coding pattern set, and carrying out the projection; after an image is collected, frequency domain transformation and time domain decoding are carried out respectively, and a vertical dominant frequency position, a horizontal period number and a wrapped phase are obtained; then, combining a main frequency position in the vertical direction with a period number and a wrapped phase in the horizontal direction, and extracting a space coordinate of a direct illumination component based on frequency position invariance; and finally, establishing a pixel homonymy point mapping relation between the projector and the camera, and realizing high-precision three-dimensional reconstruction. Compared with a traditional frequency shift method, the method has the advantages that projection patterns are greatly reduced, reconstruction precision and anti-interference performance are improved, and the method is suitable for dynamic three-dimensional measurement under complex illumination conditions such as specular reflection, semitransparent shielding and subsurface scattering.
Owner:XIANGTAN UNIV

Intelligent control method and system of motor driver

The invention discloses an intelligent control method and system for a motor driver, and the method comprises the steps: building an acoustoelectric incidence matrix through collecting harmonic current and sound pressure fluctuation data in the operation process of a motor, and forming a fault feature library; identifying an available fault mode to determine an energy collection point, and performing phase deviation processing on the collection point to generate an auxiliary driving signal; performing spectrum analysis on the sound pressure fluctuation data to obtain an acoustic characteristic spectrum, extracting an efficiency indication tone through characteristic decomposition, mapping the efficiency indication tone into a torque optimization parameter, and establishing a noise reduction control table; performing spectrum analysis on the enhanced control domain to identify a high-energy frequency band, executing a frequency shift operation to generate a safety frequency band signal, and forming a multi-frequency band management strategy in combination with a noise reduction control table; a management strategy is decomposed into parallel control flows for sequential staggered arrangement, and an energy-saving control matrix is generated; and generating a PWM control signal based on the matrix, carrying out edge reconstruction, and obtaining a softened edge waveform through an anti-resonance injection technology to complete intelligent control of the motor driver.
Owner:SHENZHEN SPARK AUTOMATION TECH CO LTD

SAR (Synthetic Aperture Radar) sea surface flow velocity inversion method based on physical guidance and data driving fusion

The invention discloses an SAR sea surface flow velocity inversion method based on physical guidance and data driving fusion, and relates to the field of flow velocity inversion, and the method comprises the steps: carrying out the non-geophysical Doppler frequency shift correction of the Doppler frequency shift observed by a spaceborne synthetic aperture radar, and obtaining the geophysical Doppler frequency shift; predicting based on a wave-induced Doppler frequency shift model according to a radar incident angle, reanalyzed wind direction data, a sea surface 10-meter height wind speed inverted by an SAR (Synthetic Aperture Radar), a simulated wind wave parameter, a simulated surge parameter and a simulated maximum wave parameter to obtain a wave-induced Doppler frequency shift; the wave-induced Doppler frequency shift model is obtained based on physical guidance and data-driven modeling; doppler frequency shift generated by sea surface flow is determined according to the geophysical Doppler frequency shift and the wave-induced Doppler frequency shift; according to the method, the Doppler frequency shift generated based on the sea surface flow is converted to obtain the sea surface radial flow velocity, the wave-induced Doppler frequency shift is accurately removed, and reliable inversion of the sea surface flow velocity is realized.
Owner:SANYA MARINE LAB

Broadband satellite signal blind demodulation reconstruction method and system based on sparse representation

The invention relates to the technical field of satellite communication signal processing, and discloses a broadband satellite signal blind demodulation reconstruction method and system based on sparse representation. The method comprises the following steps: carrying out frequency domain transformation on broadband satellite mixed signals to extract pilot frequency features to construct a beam state feature matrix, inputting the matrix into an adversarial network to generate a beam adaptive sparse dictionary, constructing a topological relation graph according to a Doppler frequency shift set, and carrying out collaborative sparse decomposition to obtain a sparse coefficient matrix; and extracting a code rate candidate set to execute parallel sparse reconstruction, determining an actual code rate through self-consistency verification to obtain a complete signal, analyzing a switching instruction, extracting time sequence statistical characteristics, predicting target domain characteristics, generating a switched sparse dictionary, and executing demodulation. The sparse decomposition precision, the code rate blind estimation accuracy, the cooperative processing efficiency and the switching continuity of the broadband satellite mixed signals are improved.
Owner:TIANJIN RONGXING GRP CO LTD

Multi-mode chip core architecture system realized based on software radio technology

The invention relates to the technical field of wireless communication, in particular to a multimode chip core architecture system realized based on a software radio technology, which comprises an anti-interference module used for executing real-time optimization on a multi-system compatible baseband data stream and calling a dynamic compensation mechanism based on dynamic frequency shift characteristics in an environment characteristic data set, adjusting a local frequency source and a channel equalization parameter through multi-stage compensation operation to obtain an anti-interference enhanced data stream; and the packaging module is used for packaging the anti-interference enhanced data stream and the positioning data into a time-hopping pulse-direct sequence code division multiple access fusion frame structure and sending the fusion frame structure through a radio frequency unit. Through an ASIC and SDR hybrid architecture and a four-level hierarchical design, a multi-system communication function is integrated, and the hardware efficiency is improved and the power consumption is reduced.
Owner:BEIJING RUIDI SPACE-TIME INFORMATION TECH CO LTD

Optical cable performance intelligent prediction method and system for data center

The invention provides an intelligent optical cable performance prediction method and system for a data center, and relates to the technical field of data center performance analys.The intelligent optical cable performance prediction method comprises the steps that firstly, an optical cable microstructure disturbance quantization model is constructed, and an optical cable is divided into a plurality of virtual quantization units in the longitudinal direction; each unit packages a real-time stress-strain state parameter and a response sensitivity coefficient of the basic structure unit, inputting a Brillouin scattering spectrum frequency shift data flow collected in real time into the model for disturbance source analysis, generating a physical excitation decomposition sequence, driving a virtual quantization unit to perform state evolution iterative operation according to the physical excitation decomposition sequence, and obtaining a Brillouin scattering spectrum frequency shift data flow model; a stress-strain state evolution track set is obtained, a time-space correlation network of optical cable link disturbance propagation is constructed according to the stress-strain state evolution track set, network flow characteristic analysis is conducted on the time-space correlation network, an early warning node set is extracted, the future evolution trend of the early warning node set is calculated, and serialized optical cable performance abnormity early warning information is generated. The optical cable performance abnormity can be predicted in advance, and stable operation of the data center optical cable is guaranteed.
Owner:SICHUAN JIAWANG OPTICAL COMM CO LTD

Vector flow inversion method combining single-station ground wave radar and spaceborne SAR (Synthetic Aperture Radar)

The invention relates to the field of ocean current remote sensing, and relates to a vector flow inversion method combining a single-station ground wave radar and a satellite-borne SAR, and the method mainly comprises the steps: calculating the frequency deviation of a first-order Bragg peak of the ground wave radar, carrying out the inversion of the sea surface radial flow of the ground wave radar, and carrying out the inversion of the sea surface radial flow of the SAR through employing a Doppler centroid anomaly method; interpolating a ground wave radar radial flow result to an SAR data grid through bilinear interpolation; inverting a single-station vector flow based on a ground wave radar radial flow result, projecting single-station vector flow data with high confidence coefficient to an SAR range direction, calculating a difference mean value of a projection flow velocity and an SAR radial flow velocity, and further calibrating the SAR radial flow; and combining a ground wave radar radial flow result with the calibrated SAR radial flow to invert a vector flow. According to the method, the defect of ocean current observation through a single means is overcome, high-precision inversion of the combined vector flow is achieved, and the method has important significance on ocean environment monitoring, disaster forecasting, shipping safety and the like.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Signal interference suppression processing method for network communication chip

The invention relates to the technical field of communication, and discloses a network communication chip signal interference suppression processing method. The method comprises the following steps: acquiring a local oscillator phase jitter sequence in real time through an on-chip phase noise monitoring unit; estimating Doppler frequency shift and channel coherence time based on the sequence; dynamically adjusting the closed-loop bandwidth of the phase-locked loop; and generating a phase compensation signal, and performing time-varying channel minimum mean square error equalization in combination with a received baseband signal to eliminate inter-symbol interference. The system integrates a phase noise monitoring function module, a channel parameter estimation function module, a phase-locked loop bandwidth regulation function module, a phase compensation generation function module and an interference joint elimination function module. By means of dynamic bandwidth reconstruction and high-precision phase compensation, the bit error rate under high-speed movement is remarkably reduced, the 5G millimeter wave communication standard requirement is met, and the method has the advantages of being achieved on a whole chip, low in delay and high in robustness.
Owner:ZHONGYING QINGCHUANG TECH CO LTD

Underwater ultrasonic signal analysis method based on Doppler effect

The invention provides an underwater ultrasonic signal analysis method based on the Doppler effect, and relates to the technical field of data processing, and the method comprises the steps: carrying out the segmentation processing of echo signal data according to a preset time window, carrying out the envelope demodulation and phase unwrapping operation of a signal in each time window, and carrying out the phase unwrapping operation of the signal in each time window; amplitude sequence, phase sequence and instantaneous frequency sequence data are extracted; extracting frequency change, amplitude change and phase change data, performing clustering processing, and distinguishing and marking different underwater target components; respectively calculating an amplitude stability index and a phase change synchronism index for each frequency track in all time windows, and screening a main frequency track according to the amplitude stability index and the phase change synchronism index; frequency shift values in the time windows are extracted, the speeds of the underwater targets in the time windows are calculated based on the Doppler effect, and the motion direction is judged in combination with frequency change data and phase change data; according to the invention, the autonomy and accuracy of underwater ultrasonic signal analysis are improved.
Owner:福建澳泰自动化设备有限公司 +1

Distribution network electric power special line anti-interference communication method based on adaptive filtering

The invention discloses a distribution network power line anti-interference communication method based on adaptive filtering, and belongs to the technical field of distribution network power line communication. According to the method, a communication signal adopting a frequency shift keying modulation mode is acquired from a power line coupler of a distribution network through a signal acquisition module, the communication signal is preprocessed by using a digital signal processing unit, spectral analysis is performed on the preprocessed signal, and characteristic parameters of interference noise are extracted; a coefficient vector of a finite impulse response adaptive filter is initialized based on the characteristic parameters, the order of the filter is in direct proportion to the reciprocal of the dominant interference frequency, fine adjustment is carried out based on noise energy distribution through a table look-up method or a linear mapping relation, and the weight coefficient of the filter is adjusted in real time in the communication process. The adjustment step length is dynamically adjusted according to the real-time estimated signal-to-noise ratio, and finally, the processed signal is output through the adaptive filter and data demodulation is carried out. The method is mainly used for improving the anti-interference capability and the communication reliability of the power private line communication of the distribution network.
Owner:JIEYANG QIANZHAN WIND POWER CO LTD

Wireless signal testing method and system for unmanned vehicle

The invention belongs to the technical field of wireless communication networks, and discloses a wireless signal testing method and system for an unmanned vehicle. The method comprises the steps of synchronously collecting electromagnetic signals inside and outside a vehicle, and generating an electromagnetic observation data set; constructing a calibration observation matrix based on a vehicle attitude, position information, a road side reference signal and a communication link state, extracting a candidate interference cluster set and constructing a power curve, and calculating a Pearson's correlation coefficient and Doppler frequency shift to identify an interference type label; determining an interference source position of each interference cluster by adopting a corresponding interference source positioning algorithm according to the interference type label; comprehensively evaluating the communication reliability of the wireless link of the whole vehicle by combining all interference source positions, corresponding labels and power curves and fusing communication link performance indexes and vehicle state information; according to the invention, accurate identification and traceability of wireless link interference of the unmanned vehicle are realized, and the accuracy and real-time performance of communication reliability evaluation are improved.
Owner:WUHU SIMBA NETWORK TECH CO LTD

Laser radar ranging method based on parallel detection

The invention provides a laser radar ranging method based on parallel detection, which relates to the technical field of laser radar ranging, and comprises the following steps: generating N lasers with different wavelengths, splitting beams by a beam splitter, separating optical channels with N independent wavelengths by a demultiplexer, performing frequency shift processing, combining N paths of optical signals after frequency shift through a beam combiner, and combining the N paths of optical signals after frequency shift through a beam splitter; generating a beam of composite reference light containing N wavelengths, wherein each wavelength has a specific frequency shift; signal light returned from a target and the composite reference light are jointly input into a coupler for frequency mixing so as to generate an optical beat frequency signal, and operation processing is performed to calculate the target distance and the target radial speed corresponding to each wavelength. According to the laser radar ranging method provided by the invention, parallel detection of the laser radar can be realized, beat frequency signals corresponding to a plurality of different wavelengths can be distinguished only by integrating a group of detectors, a cross-group amplifier and an analog-to-digital converter, the cost is greatly reduced, and the complexity of the system is reduced.
Owner:JILIN UNIVERSITY

Method and system for measuring gravitational potential by satellite-air-ground optical clock time-frequency comparison system

The invention discloses a method and a system for measuring gravitational potential by a satellite-air-ground optical clock time-frequency comparison system. According to the method for measuring the gravitational potential, an optical clock superior to 110-18 orders of magnitude serves as the basis, a free space time-frequency comparison link based on an optical frequency comb serves as a bridge, the optical clocks among the satellite, the air and the ground are connected, high-precision time-frequency transmission is carried out, a gravity frequency shift signal is accurately extracted through time-frequency comparison of a remote clock, and the gravitational potential is measured. And then the gravity potential difference of the position where the remote clock is located is obtained by using a gravity frequency shift equation, and the gravity potential difference between air and ground or between any ground stations is determined.
Owner:WUHAN UNIV

Method and device for determining moon gravity field by using inter-satellite frequency signal time-frequency link

PendingCN120779490AGravitational wave measurementLunar gravityFrequency shift
The invention relates to a method and device for determining a lunar gravity field by using an inter-satellite frequency signal time-frequency link, and the method comprises the steps: connecting an earth observation station, a static satellite and a lunar polar orbit satellite which are provided with an atomic clock through a satellite carrying a clock system based on a generalized relativistic theory, and carrying out the time-frequency transmission through a satellite time-frequency transmission method, the gravity potential difference between the earth and the satellite and the gravity potential difference between the satellite and the moon polar orbit satellite are measured through a gravity frequency shift method, the gravity potential data of the moon polar orbit satellite are obtained through an inter-satellite time-frequency link according to the earth gravity potential data, and then the moon gravity field is determined through a physical geodetic measurement method. Therefore, the problems that the prior art is difficult to implement on the surface of the moon and the gravity potential of the moon and the earth cannot be connected are solved.
Owner:WUHAN UNIV

Holmium and ytterbium co-doped mid-infrared microsphere Raman laser and preparation method thereof

The invention provides a holmium and ytterbium co-doped mid-infrared microsphere Raman laser and a preparation method thereof, and relates to the technical field of laser preparation, the holmium and ytterbium co-doped mid-infrared microsphere Raman laser comprises an infrared transmission optical fiber, a pump light source, holmium and ytterbium co-doped tellurate glass microspheres and passive tellurate glass microspheres, pump light emitted by the pump light source is guided to a conical region through the infrared transmission optical fiber, and the holmium and ytterbium co-doped tellurate glass microspheres and the passive tellurate glass microspheres are arranged in the conical region; sequentially carrying out optical coupling with holmium and ytterbium co-doped tellurate glass microspheres and passive tellurate glass microspheres; in the holmium and ytterbium co-doped tellurate glass microspheres, the doping amount of the holmium element is 0.3%, and the doping amount of the ytterbium element is 0.45% according to the mass percentage. Compared with the prior art, through the cascade structure of the holmium-ytterbium co-doped microspheres and the passive microspheres, three-step wavelength conversion of pump light-rare earth ion lasing-Raman frequency shift is realized in a single system for the first time, and the wavelength limitation that a traditional single microsphere depends on a rare earth ion fixed energy level is broken through.
Owner:NINGBO UNIV

A non-contact track frequency-shift signal online monitoring method and system

The application discloses a kind of non-contact track frequency shift signal online monitoring method and system, applied to intelligent monitoring technical field, method includes: receiving first measured voltage and second measured voltage;First measured voltage and second measured voltage are input first conditioning circuit by first transmission line, receive the first output voltage output by first conditioning circuit, and the parallel transmission line formed after first measured voltage and second measured voltage are connected in parallel by second transmission line and third transmission line are input second conditioning circuit, receive the second output voltage output by second conditioning circuit;According to first output voltage and second output voltage, calculate first measured voltage.The application is realized by the way of double-path simultaneous monitoring, reduces the influence of the related capacitance value change caused by environmental conditions on monitoring result, to effectively improve monitoring precision, and then provides solid foundation for non-contact frequency shift signal back-end processing.
Owner:MIANYANG TEACHERS COLLEGE +1

Seawater temperature, salinity and sound velocity inversion method based on Brillouin laser radar

The invention discloses a seawater temperature, salinity and sound velocity inversion method based on a Brillouin laser radar, and belongs to the technical field of marine environment monitoring. According to the method, the temperature, salinity and sound velocity of seawater are inverted by measuring the Brillouin frequency shift and the Brillouin line width and combining the MLP neural network; the method specifically comprises the steps of collecting seawater parameter data of different sea areas, different seasons and different depths and corresponding frequency shifts and line widths; carrying out data preprocessing and standardization on the collected data; and establishing an inversion model by using an MLP neural network, and outputting temperature, salinity and sound velocity. The multi-layer perceptron MLP neural network processes frequency shift and line width data measured by the Brillouin laser radar, high-precision and real-time inversion of seawater temperature, salinity and sound velocity is achieved, the parameter range is remarkably expanded, the inversion precision is improved, and efficient and reliable marine environment monitoring is provided.
Owner:NANJING MULTI BASE OBSERVATION TECH RES INST CO LTD

Multi-frequency omnidirectional unmanned aerial vehicle active defense system and method

ActiveCN120896667ARadio transmissionCommunication jammingCarrier signalResonance analysis
The invention discloses a multi-frequency omnidirectional unmanned aerial vehicle active defense system and method, and the method comprises the steps: obtaining defense region parameters, and constructing a navigation signal generation task library based on the coverage requirements of GPSL1 and Beidou B1 / B2 / B3 frequency bands; resonance interference points are determined through carrier locking resonance analysis, Doppler frequency shift traps are designed, frequency shift fragility features are extracted in combination with C / A code recombination processing, and a targeted interference enhancement domain is constructed; the method comprises the following steps: respectively carrying out constellation topology reconstruction on a GPS (Global Positioning System) and a Beidou system, generating false orbit parameters through ephemeris data tampering, and forming a mixed defense signal domain by utilizing carrier phase interleaving processing; analyzing signal power to determine strong and weak interference areas, and setting graded attenuation parameters to construct a graded signal attenuation field; the attenuation field and the interference enhancement domain are fused to generate dynamic simulation parameters, false orbit parameters are adjusted in real time to generate a coordinate input mode, a high-dynamic navigation signal is reconstructed, a satellite working mode is selected, an L1 / B1 / B2 / B3 multi-band radio frequency output instruction is finally generated, and all-dimensional intelligent deception jamming of the unmanned aerial vehicle navigation system is achieved.
Owner:CCCC REMOTE SENSING TIANYU TECH JIANGSU CO LTD

Multi-constellation satellite signal intelligent identification and adaptive acquisition method and system

The invention relates to the technical field of satellite signal processing, and discloses a multi-constellation satellite signal intelligent identification and adaptive acquisition method and system. The method comprises the following steps: performing short-time Fourier transform on a received signal to extract a frequency trajectory matrix, calculating a Doppler frequency shift rate and an acceleration, inputting a multi-task neural network in combination with modulation domain characteristics, and outputting constellation category and interference type identification results, when a low-orbit satellite is identified, a carrier frequency deviation track and uncertainty are predicted through a long-short term memory network, the frequency of a numerical control oscillator is adjusted in advance according to a prediction result, a search window and integral time are dynamically set, and corresponding anti-interference strategies are executed for different interference types. And periodically monitoring the signal quality index, and triggering strategy upgrading when the performance improvement rate is lower than a threshold value. According to the invention, the signal capture success rate and tracking stability in a multi-constellation mixed environment are improved.
Owner:TIANJIN RONGXING GRP CO LTD

High-spatial-resolution distributed optical fiber sound wave sensing system based on FPGA real-time demodulation

The invention discloses a high-spatial-resolution distributed optical fiber sound wave sensing system based on FPGA real-time demodulation. The system comprises a narrow linewidth laser source module, a first coupler, a high-bandwidth sweep frequency signal modulation module, a circulator, a coherent receiving and photoelectric conversion module and an FPGA integrated module. A laser source emitted by the narrow linewidth laser source module is divided into about 10% of reference light and about 90% of detection light through the first coupler. The FPGA integrated module is connected with the high-bandwidth sweep frequency signal modulation module, and transmits a sweep frequency radio frequency pulse signal and a frequency shift radio frequency pulse signal to the high-bandwidth sweep frequency signal modulation module; the high-bandwidth sweep frequency signal modulation module is connected with the sensing optical fiber through the circulator so as to output sweep frequency optical pulses; the sensing optical fiber is connected with the coherent receiving and photoelectric conversion module through the circulator to transmit Rayleigh backscattered light; the coherent receiving and photoelectric conversion module is connected with the FPGA integrated module, and the FPGA integrated module carries out signal processing to obtain vibration information on the optical fiber.
Owner:BEIJING JIUZHOUYIGUI SHOCK & VIBRATION ISOLATION

Ultralow-temperature cascade refrigeration device

The invention discloses an ultralow-temperature cascade refrigeration device, belongs to the technical field of refrigeration devices, and solves the problems that when a low-temperature screw compressor continuously operates below-80 DEG C, organic acid generated by hydrolysis of trace moisture and ester lubricating oil and metal chips form colloidal deposition, the resistance of a slide valve is increased, displacement lag is caused, and the service life of the slide valve is prolonged. However, the sensor only feeds back an instruction signal and cannot be monitored by a control system, and finally bearing wear or energy efficiency reduction is caused. Comprising a screw compressor and a slide valve state monitoring circuit arranged in the screw compressor. The actual displacement of the slide valve is measured in real time through double-frequency laser interference, the thickness of jelly is analyzed in combination with acoustic surface wave frequency shift, the fault index is calculated after dynamic compensation, early warning is conducted when the limit is exceeded, a blind area of a traditional sensor is eliminated, diagnosis is conducted in advance, and compressor bearing abrasion is avoided.
Owner:酷凌时代科技(浙江)有限公司

Underwater manipulator motion balance real-time monitoring method based on acoustic sensing

The invention provides an underwater manipulator motion balance real-time monitoring method based on acoustic sensing, which comprises the following steps: if a frequency shift range exceeds a preset range threshold, filtering a signal data set, and separating superposed components of a friction sound signal and a water flow interference sound to obtain a preliminarily separated friction sound signal; performing short-time Fourier transform processing on the preliminarily separated friction sound signals, extracting time-frequency features of the friction sound signals, and obtaining a friction sound feature set; calculating the signal energy ratio of the friction sound signal to the water flow interference sound by analyzing the frequency spectrum difference between the friction sound feature set and the water flow interference sound, screening the interference sound according to the signal energy ratio, and rejecting the screened interference sound to obtain a separation signal; and when it is recognized that the manipulator executes the complex track task, track complexity is recognized, the position of the acoustic sensor array is dynamically adjusted according to the track complexity, the dynamic layout of the acoustic sensor array is optimized, and array configuration is obtained.
Owner:STATE GRID SHANDONG ELECTRIC POWER CO QINGDAO HUANGDAO DISTRICT POWER SUPPLY CO

PINN and optical fiber sensing fusion-based line icing prediction method

The invention discloses a PINN and optical fiber sensing fusion-based line icing prediction method, and belongs to the technical field of overhead line icing monitoring, and the method comprises the steps: building a line state constraint between a reference working condition and a current working condition, and providing a physical constraint for PINN model training; measuring to obtain an overhead line vibration signal, performing selective weighting on a low frequency, extracting a main modal frequency, and constructing a low-frequency feature vector; using the temperature mean value as the temperature value of the overhead line, constructing a Brillouin spectrum data residual error, and inverting the temperature and strain; brillouin frequency shift features are extracted, and Brillouin frequency shift feature vectors are generated; inputting the low-frequency feature vector and the Brillouin frequency shift feature vector as conditions into a PINN model, and training the model; carrying out backtracking correction on prediction in a past time window by taking an on-site overhead line icing value as an anchor point; and predicting an icing thickness result of a future time domain output by the optimized PINN model. The overhead line icing thickness prediction precision can be improved, and the line operation and maintenance efficiency can be improved.
Owner:NORTH CHINA ELECTRIC POWER UNIV +2

Wireless communication device and method for wideband spectrum monitoring

A wireless communication device includes RF input to receive RF signals in a range of DC to 300 GHz. The wireless communication device includes RF front-end that includes plurality of band filters to apply band-specific filtering operation to the received RF signals to obtain filtered RF signals. A local oscillator generates tunable local oscillator frequencies above a threshold frequency. The wireless communication device includes circuitry to execute a frequency shifting operation in one or more frequency conversion stages in which one or more tuned local oscillator frequencies above the threshold frequency are injected at the circuitry to push image frequencies above the threshold frequency and shift the filtered RF signals to predefined intermediate frequencies. The filtered RF signals are digitized and a processor concurrently processes the digitized down-converted signals across predefined intermediate frequencies, based on configuration of MLO parameters and performs a real-time or near real-time enhanced spectrum monitoring operations.
Owner:PELTBEAM INC

Abnormity detection method and device based on receiving power of low-orbit satellite-borne GNSS (Global Navigation Satellite System) receiver

The invention discloses an anomaly detection method and device based on the receiving power of a low-orbit satellite-borne GNSS receiver, and the method comprises the steps: obtaining a source receiving power sequence of the low-orbit satellite-borne GNSS receiver, and carrying out the enhancement processing based on Doppler frequency shift compensation and ionospheric noise filtering, and then generating a to-be-detected receiving power sequence; performing feature extraction on the to-be-detected receiving power sequence and then generating a receiving power feature vector based on a multi-scale entropy feature and a chaotic feature; and comparing the received power feature vector with a pre-constructed dynamic anomaly threshold to generate an anomaly detection result. According to the method, time sequence mismatching caused by frequency shift is overcome, energy distortion caused by ionosphere disturbance is also remarkably weakened, so that the accuracy and sensitivity of a subsequent nonlinear feature extraction process are guaranteed, and particularly, the robustness and effectiveness of GNSS receiving power anomaly detection can be remarkably improved in a complex dynamic space environment.
Owner:BEIJING SATELLITE NAVIGATION CENT

Doppler frequency shift compensation method and apparatus, and device and storage medium

The present application relates to the field of wireless communications. Provided are a Doppler frequency shift compensation method and apparatus, and a device and a storage medium. The method comprises: acquiring ephemeris information of a satellite; on the basis of the ephemeris information and a first frequency shift value which is estimated using a beam position center, compensating for a synchronization signal block (SSB) within a beam position, and sending a pre-compensated SSB to a terminal; and then, on the basis of a second frequency shift value, which has been updated via interpolation, compensating for an uplink signal and a downlink signal within the beam position, and sending a pre-compensated downlink signal to the terminal. A terminal can perform Doppler frequency shift compensation without relying on GNSS location information, thereby reducing the cost and usage power consumption of the terminal, decreasing the number of times that the terminal performs frequency sweeping in an initial access stage, and shortening the latency for the terminal to access a cell.
Owner:SHANGHAI SATELLITE NETWORK RESEARCH INSTITUTE CO LTD

Physical frame structure design method suitable for satellite-ground high-order high-bit-rate wireless communication

The invention provides a physical frame structure design method suitable for satellite-ground high-order high-bit-rate wireless communication, which comprises the following steps of: slicing service data according to a preset length, and generating a baseband frame based on the obtained data slices; performing scrambling processing on the baseband frame to obtain a scrambled baseband frame; sequentially executing preset error correction coding processing on the scrambled baseband frames to obtain coded frames; performing internal interleaving processing on the coding frame to obtain internal interleaving data, and forming a first physical frame; performing external interleaving processing on the first physical frame to obtain external interleaving data; mapping the outer interleaved data into a symbol stream; performing physical frame framing based on the symbol stream to obtain a second physical frame; and performing scrambling processing on the to-be-scrambled symbols except the physical frame header in the second physical frame to obtain a scrambled physical frame, and performing modulation based on the scrambled physical frame to perform data transmission, thereby improving phase noise resistance and channel distortion resistance, enhancing Doppler frequency shift resistance, and optimizing transmission efficiency and reliability.
Owner:北京融为科技有限公司