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195 results about "Frequency correction" patented technology

The Frequency Correction Channel is a broadcast channel used by GSM base stations. It provides a unique tone of 67.7 kHz for the Mobile Stations. This tone is used to synchronize the local clock of the mobile receiver with the base station. This is needed to correctly extract the data.

Multi-motor pulse speed regulation control method and system

The invention provides a multi-motor pulse speed regulation control method and system, and relates to the technical field of motor control, the method comprises the steps that a target set quantity and a target motor identifier are obtained, a target driving parameter is obtained through conversion according to a parameter set associated with the target motor identifier, and the parameter set comprises an elastic modulus value and a stress relaxation coefficient of a peristaltic pump hose; real-time driving parameters are maintained for the multiple pulse output channels respectively, and refreshing is carried out at the synchronization moment; operating state feedback values of a peristaltic pump channel and a stirring motor channel are collected, a water hammer effect frequency component and an impeller passing frequency component are extracted, and correction is carried out based on the elastic parameters; and judging whether a cross-channel resonance judgment condition is met or not, and when the condition is met, determining a frequency correction amount and a phase correction amount and applying the correction amounts to at least one pulse output channel, thereby reducing the resonance risk and stabilizing the system operation.
Owner:SHANGHAI BAOXING BIOLOGY EQUIP ENG CO LTD

Optical remote sensing satellite high and low frequency relative radiation error correction method and system

The invention discloses an optical remote sensing satellite high and low frequency relative radiation error correction method and system, and the method comprises the steps: S1, carrying out the systematic high frequency radiation error calibration of a remote sensing image, so as to eliminate stripe noise; s2, performing frequency domain decomposition on the image after high-frequency correction, and separating high and low frequency components; s3, calculating a global statistical moment of the low-frequency component as a correction reference; s4, calculating a local statistical moment of the low-frequency component column by column; s5, calculating an independent correction coefficient for each column according to the global and local statistical moments; s6, correcting the low-frequency component by using the correction coefficient; and S7, recombining the corrected low-frequency component with the original high-frequency component to generate a final image. The method is suitable for improving the quality of the remote sensing image with multiple composite radiation errors, high-frequency stripes and low-frequency brightness gradient can be effectively eliminated, original texture details of ground features are reserved to the maximum extent in the correction process, and the radiation fidelity is guaranteed.
Owner:HUBEI NORMAL UNIV

Flywheel AFE energy storage power supply system for data center

The invention relates to the technical field of data center energy storage and power supply, and discloses a flywheel AFE energy storage and power supply system for a data center, which comprises a flywheel energy storage unit, an AFE control module, a hierarchical energy scheduling module, a dynamic balance adjustment module and a feedback optimization module. The flywheel energy storage unit constructs a multi-stage energy buffer topology through a rotating speed monitoring node and a kinetic energy conversion network; the AFE control module realizes steady-state and transient-state control by using a multi-mode switching link of the vector modulation unit and inhibits harmonic waves in combination with the direct-current bus compensation unit; the hierarchical energy scheduling module generates a bus voltage reference strategy through a dynamic coordination model of the master control coordination node, and load power supply priorities are sorted through a dynamic priority distribution unit. The dynamic equalization adjustment module realizes power phase synchronization compensation and modulation frequency correction, and the feedback optimization module corrects a power supply strategy based on a closed loop of a bus harmonic evaluation network. The system improves the power supply stability, efficiency and reliability of the data center.
Owner:SHENYANG MICRO CONTROL ACTIVE MAGNETIC LEVITATION TECH IND RES INST CO LTD

Intermediate frequency transformer insulation electrothermal aging evaluation method, test device and storage medium

The invention discloses a medium-frequency transformer insulation electrothermal aging evaluation method, a test device and a storage medium, and relates to the technical field of power transformers. The medium-frequency transformer insulation electric heating aging test device comprises a function signal generator, a high-voltage power amplifier, a protection and isolation unit, an electric-heat combined aging oven and a detection and monitoring unit. The electrothermal aging evaluation method comprises the following steps: acquiring an aged sample, testing the ultimate tensile strength and polymerization degree of the aged sample, introducing a frequency correction factor to correct an attenuation constant under a power frequency condition, establishing tensile strength attenuation equations under different frequencies, and evaluating the tensile strength of the aged sample. And respectively fitting the maximum value of the accumulated loss rate and the change rate of the accumulated loss rate under different frequencies to obtain a polymerization degree accumulated loss rate improvement formula, and carrying out aging characteristic analysis on the insulation of the intermediate-frequency transformer according to the actual working condition of the insulation of the intermediate-frequency transformer. According to the technical scheme, the blank of medium-frequency transformer insulation electrothermal aging research is filled.
Owner:SHANDONG UNIV +2

Frequency correction circuit for switching converters, corresponding converter device and method

A correction circuit for a switching converter counters undesired reduction of switching frequency in response to a decrease in a load current at a converter output node. Detection circuitry receives a reference clock signal indicative of a lower bound for the switching frequency of the converter and a pulsed drive signal indicative of the switching frequency of the converter. In response to the switching frequency of the converter falling below said lower bound for the switching frequency of the converter, the detection circuitry produces an error signal. Current sink circuitry coupled to the output node of the converter sinks from the output node of the converter corrective current in response to receipt of the error signal from the detection circuitry.
Owner:STMICROELECTRONICS SRL

Resonant frequency identification and suppression method and system of mechanical-gear-free integrated vernier motor

The invention discloses a resonant frequency identification and suppression method and system for a mechanical-gear-free integrated vernier motor, belongs to the field of mechanical-gear-free integrated vernier motor control, and is suitable for robot joint driving, high-precision servo systems and other scenes. The invention relates to a resonant frequency on-line rapid identification method, which comprises the following steps of: introducing an additional control degree of freedom into a traditional second-order generalized integrator-frequency-locked loop, optimizing an orthogonal signal generation process, and shortening convergence time in combination with an adaptive frequency correction link; the problems that a traditional resonant frequency identification algorithm is poor in identification accuracy and low in convergence speed are solved. According to the high-performance resonance suppression strategy, disturbance is estimated in real time through a linear expansion state observer; parameter setting is simple, the problem that multi-parameter setting of a traditional wave trap is complex is solved, and the strong-robustness resonance suppression effect under load inertia changes is achieved.
Owner:SOUTHEAST UNIV

High-precision liquid level measuring device and method based on sweep frequency interference measurement

The invention discloses a high-precision liquid level measuring device and method based on sweep frequency interference measurement, belongs to the technical field of optical-mechanical-electrical integrated measurement, and is used for high-precision liquid level measurement. The light path is composed of a frequency sweep correction light path and a measurement calibration light path. The device comprises a sweep-frequency light source, an optical fiber splitter, a high-speed acquisition card, a computer, an optical fiber circulator, an optical fiber reflector, a Fabry-Perot (FP) etalon, a balanced photoelectric detector (BPD), a liquid level measuring probe and the like. The FP etalon realizes a sweep frequency correction function, a measurement calibration light path switches channels through the one-to-two photoelectric switch, and high-speed signal acquisition is carried out through the BPD and the high-speed acquisition card. The measuring process is free of mechanical movement and has the advantage of being free of maintenance; the FP etalon is introduced for nonlinear frequency sweeping calibration, the measurement precision is improved, the micron-level measurement precision can be achieved under the better experiment condition, and the non-contact measurement method can meet the requirement for high-precision liquid level measurement in the fields of chemistry, chemical engineering and the like.
Owner:CHINA UNIV OF PETROLEUM (EAST CHINA)

Anti-noise-interference high-precision optical coherent ranging frequency parameter estimation method

PendingCN121631980AUsing optical meansFrequency spectrumSource spectrum
The invention provides an anti-noise interference frequency parameter estimation method for high-precision optical coherence ranging, which comprises the following steps: acquiring a spectral interference signal of an optical low-coherence interference system and a reference light spectral signal output only by a reference arm, and converting the spectral interference signal into interference signals with wave number space arranged at equal intervals, carrying out spectral density amplitude normalization to obtain a standard interference signal so as to eliminate interference of light source spectrum fluctuation and non-uniform sampling on frequency estimation; hanning window modulation is applied to a standard interference signal, spectrum leakage is suppressed, spectrum analysis is performed on the modulated signal, a peak value and an adjacent secondary peak value of a spectrum main lobe are extracted, a frequency correction amount is calculated based on a peak value and secondary peak value amplitude ratio relation derived by a Hanning window spectrum mode function, and an accurate frequency of the interference signal is obtained; and calculating the displacement of the object to be measured according to the product of the accurate frequency and the spectral resolution of the optical low-coherence interference system in combination with the refractive index of the light in the measurement medium.
Owner:HUANENG (FUJIAN) ENERGY DEVELOPMENT LIMITED COMPANY FUZHOU BRANCH +1

Satellite-ground radar reflectivity factor consistency evaluation and deviation tracing method and system

The invention relates to a satellite-ground radar reflectivity factor consistency evaluation and deviation traceability method and system, and belongs to the field of radar calibration evaluation, and the method comprises the steps: generating reference ground radar scanning parameters according to geographical environment multi-source heterogeneous data; acquiring satellite-ground radar data according to the scanning parameters of the reference ground-based radar when the satellite-borne radar passes the scene, and performing preprocessing and space-time matching to obtain a satellite-ground radar data pair; based on the target correction information of each height level region, performing sectional frequency correction on the spaceborne radar data to obtain an optimal satellite-ground radar data pair; and carrying out reflectivity factor consistency evaluation on the optimal satellite-ground radar data pair, taking an obtained evaluation result as a tracing reference, and carrying out deviation tracing calibration estimation on the service ground-based radar in combination with a satellite-ground radar reflectivity factor consistency evaluation result of the service ground-based radar. According to the method, the technical problems of precise evaluation of systematic deviation of satellite-ground radar data and unified evaluation and calibration of multi-service satellite-ground radars are solved.
Owner:长沙气象雷达标校中心

Server-based cross-frequency correction for precise positioning

An example method performed at a mobile device for position determination may comprise receiving from a server correction data associated with (1) a first pseudorange measurement of a first GNSS signal sent from a satellite vehicle on a first GNSS carrier frequency and (2) a second pseudorange measurement of a second GNSS signal sent from the satellite vehicle on a second GNSS carrier frequency. The method also may comprise measuring a third GNSS signal sent from the satellite vehicle and received at the mobile device on a third GNSS carrier frequency, to generate a third pseudorange measurement. The method also may comprise determining the position of the mobile device using (a) the third pseudorange measurement of the third GNSS signal on the third GNSS carrier frequency and (b) the correction data. The correction data received from the server may include a virtual pseudorange measurement for the third GNSS carrier frequency.
Owner:QUALCOMM INC

Microwave-assisted photon terahertz frequency offset compensation method

The invention discloses a microwave-assisted terahertz frequency offset compensation method, and aims to solve the problem of signal distortion caused by frequency offset in terahertz communication. According to the method, a microwave signal is introduced as an auxiliary reference to realize real-time estimation and compensation of terahertz emission signal frequency offset. The specific process comprises the steps of injection of a microwave reference signal, spectrum analysis of a receiving end, offset extraction and frequency correction of a baseband signal. Compared with a traditional frequency offset compensation scheme, the method can effectively improve the precision and stability of system frequency synchronization, reduce the hardware complexity and enhance the anti-interference capability of a communication system, has a good application prospect, and is particularly suitable for a terahertz wireless communication system with high frequency width and high rate.
Owner:SOUTHEAST UNIV

Method for adjusting audio frequency and audio frequency adjustment device

A method for adjusting audio frequency includes steps of: obtaining initial frequency and temporary data storage of audio data input to a buffering unit; performing a first adjustment procedure on initial frequency to obtain a first variation of temporary data storage corresponding to a first change of initial frequency; calculating a first frequency correction amount according to first variation and a first period of first adjustment procedure; adjusting initial frequency into first frequency according to first frequency correction amount; inputting first frequency into buffering unit; performing a second adjustment procedure on first frequency to obtain a second variation of temporary data storage corresponding to a second change of first frequency; calculating a second frequency correction amount according to second variation and a second period of second adjustment procedure, which first period is less than second period; and adjusting first frequency into target frequency according to second frequency correction amount.
Owner:REALTEK SEMICON CORP

Time-frequency offset tracking method in Tiantong satellite monitoring low-orbit satellite system

The invention discloses a time-frequency offset tracking method in a Tiantong satellite monitoring low-orbit satellite system, which belongs to the field of satellite communication, and comprises the following steps: acquiring satellite orbit information, satellite ephemeris information and positioning information of a low-orbit satellite, and resolving current Doppler frequency offset information; performing frequency pre-compensation according to the Doppler frequency offset information, and performing compensation by using the frequency offset captured by the FCCH; the satellite-borne terminal receiver carries out carrier frequency estimation by using a downlink channel, so that the carrier residual frequency difference of a received signal is estimated, and frequency correction is carried out; starting downlink timing tracking; uplink frequency offset compensation is started, so that the frequency of a signal from the low-orbit satellite to the Tiantong satellite is the expected carrier frequency of the Tiantong satellite; and carrying out transmission timing correction by adopting the spaceborne terminal timing drift rate, and carrying out uplink timing adjustment. According to the method, normal access and stable data transmission of the satellite-borne terminal can be realized.
Owner:RPCOM INTEGRATED CIRCUIT CO LTD

Contactless electric power transmission system that corrects a request frequency of electric power transmission

A contactless electric power transmission system includes an electric power reception device and a control device. The electric power reception device receives AC electric power transmitted in a contactless manner from an electric power transmission device. The control device includes: a coil temperature detection portion that acquires temperatures of a secondary side coil, a magnetic member, and a secondary side capacitor of the electric power reception device; a magnetic member temperature detection portion; and a capacitor temperature detection portion. The control device includes a request frequency correction portion that corrects a request frequency of electric power transmission by the electric power transmission device based on the temperatures of the secondary side coil, the magnetic member, and the secondary side capacitor.
Owner:HONDA MOTOR CO LTD

County isolated network frequency correction control system supported by multi-resource cooperation

The invention discloses a county isolated network frequency correction control system supported by multiple resources cooperatively, which relates to the technical field of intelligent power grids and comprises a control center, and the control center is connected with a resource acquisition module, a cooperative processing module, a support analysis module and an intelligent correction module. Constructing a power grid comprehensive layout map, collecting power grid composite data, extracting an isolated grid regional frequency to construct a regional frequency dynamic graph, and performing frequency tense judgment on the regional frequency dynamic graph to obtain an isolated grid frequency judgment result; performing frequency measurement updating on the power grid comprehensive layout diagram to obtain an abnormal power grid marking diagram; performing anomaly grading on the abnormal power grid mark graph to obtain a node frequency deviation degree, and performing frequency supplementary rescue on the isolated network block according to the node frequency deviation degree to obtain a dynamic correction scheme; the frequency control capability is improved and the power system stability is enhanced.
Owner:YANBIAN ELECTRICAL BUREAU

A phase-locked loop without frequency divider and a reference double-delay frequency locking method thereof

The application discloses a frequency divider-free phase-locked loop and a reference double-delay frequency locking method thereof. The sub-sampling phase-locked loop architecture receives an output of an oscillator and feeds back the output to a reference double-delay frequency locking loop. The output end of a reference double-delay generator in the reference double-delay frequency locking loop is electrically connected with the input end of a sample-and-hold circuit, and the output end of the sample-and-hold circuit is electrically connected with the input end of an automatic phase error state detector. The sample-and-hold circuit simultaneously receives an oscillator output feedback signal of the sub-sampling phase-locked loop architecture. The output end of the automatic phase error state detector is electrically connected with the input end of an adaptive output frequency corrector, and the output end of the adaptive output frequency corrector is electrically connected with the sub-sampling phase-locked loop architecture. Unequal double-reference clock delays are introduced, the sample-and-hold circuit is combined to realize the detection of the output frequency, a new frequency locking loop working at a reference frequency is used to replace a traditional frequency locking loop, and the problem of high power consumption caused by a high-frequency frequency divider is solved.
Owner:UESTC (SHENZHEN) ADVANCED RES INST

Motor bearing wear monitoring device, correction method for motor bearing wear monitoring device, and correction program

The motor bearing wear monitoring device (5, 5A) monitors wear states of bearings (32, 33) with detection coils (C1 to C8). The device includes a storage (56, 56A) storing correspondence information on wear amount of the bearing and a voltage value corresponding to the wear amount, a wear amount detection unit detecting the wear amount of the bearing, based on differences between each of the detection coils (C1, C3) and between each of the detection coils (C5, C7), and a difference between a combined signal of the detection coils (C2, C4) and a combined signal of the detection coils (C6, C8); a signal generation unit (53, 553) generating an amplitude signal, based on the detection signal or the combined signal that are used for generating the difference; and a correction unit (551, 554) correcting the difference or the correspondence information depending on a driving frequency, based on the amplitude signal.
Owner:NIKKISO CO LTD

System and method for synchronizing non-linear resonators in chaotic regime

The invention relates to a system comprising a first and second generator (E1, E2) delivering excitation signals to a first and second resonator (R1, R2) generating chaotic signals. The resonators (R1, R2) are structurally different and coupled to one another. Advantageously, this system makes it possible to synchronize the chaotic signals and comprises: ● a dissipation correction module acting on the modulation frequencies fm1, fm2 of the excitation signals, ● a non-linearity correction module acting on the amplitudes of the excitation signals, ● a resonant frequency correction module acting on the carrier frequencies fc1, fc2 of the excitation signals, ● an amplitude correction module acting on the amplitudes of the chaotic signals. The invention also relates to a synchronization method based on this system.
Owner:UNIVERSITE GRENOBLE ALPES +2

Unit for radio frequency calibration

The utility model relates to a unit used for radio frequency calibration, comprising an outer side support frame, two opposite ends of the outer side support frame are respectively plugged with a sealing end plate and an auxiliary end plate, and one side of the sealing end plate and one side of the auxiliary end plate are respectively provided with a sealing groove used for plugging and supporting. A plurality of inserting rods for positioning and supporting are arranged on the sealing end plate, and a plurality of connecting pins for connecting and supporting are uniformly arranged on the outer side of the outer side supporting frame. According to the radio frequency calibration unit, limiting support is provided for assembly and use of components in the frequency calibration unit based on support of the outer side support frames, the connection strength of the device during installation and use is improved through arrangement of the insertion rods, and the same outer side support frame can be adjusted to be square or square for use according to actual use requirements; and the device can be vertically or horizontally mounted and used, so that the device can be used in various forms and various connection states, and the use convenience of the device is improved.
Owner:NANJING SAIGEW MICROWAVE SCI & TECH

Magnetic resonance spectrum water peak modeling and post-processing method based on Hankel singular value decomposition

The invention discloses a Hankel singular value decomposition-based magnetic resonance spectrum water peak modeling and post-processing method. The method comprises the following steps of: acquiring original multi-channel FID (Flame Ionization Detector) signals by a PRESS sequence; combining multi-channel signals, and performing frequency correction and eddy current correction; reconstructing and deducting a time domain water peak model, and executing exponential filtering processing; and performing baseline correction by adopting an asymmetric least square method to obtain a final spectrogram. Accurate modeling and removal of residual water peaks are realized by utilizing Hankel structure matrix singular value decomposition, adaptive baseline correction is performed by introducing an asymmetric least square method, interference of the residual water peaks is effectively reduced, the baseline smoothness of a spectrogram and the distinguishability of metabolic peaks are improved, and the method can be used for realizing accurate modeling and removal of the residual water peaks under the condition of not depending on additional modulation of a collection end or increasing of sequence complexity. The time domain signals are subjected to structured matrix decomposition to realize accurate modeling and removal of residual water peaks, the signal-to-noise ratio and metabolic peak resolution of the spectrogram are remarkably improved, the operation is stable, the robustness is high, and the obtained final MRS spectrogram can meet clinical requirements.
Owner:SUZHOU LONWIN MEDICAL SYST CO LTD

Method for operating a fast start-up oscillator system, and fast start-up oscillator system

A method for operating a fast start-up oscillator system, which includes a reference oscillator and a quartz oscillator connected to an electronic oscillator circuit, which is provided to supply a master clock signal to a start-up controller configured to perform a fast start-up procedure of the quartz oscillator via the reference oscillator. The start-up controller includes a calculation unit and a memory unit for storing data in connection with the reference oscillator for starting the quartz oscillator. The method includes parameterising the calculation unit for starting the quartz oscillator, generating excitation bursts, determining a phase deviation in different successive periods between the oscillation of the reference oscillator and the oscillation of the quartz oscillator, calculating a frequency error in the calculation unit, and correcting the frequency of the reference oscillator to the frequency of the quartz oscillator.
Owner:THE SWATCH GRP RES & DEVELONMENT LTD

Server hardware acceleration control system based on noise temperature coupling

The invention relates to the technical field of server hardware control, and discloses a server hardware acceleration control system based on noise temperature coupling. The system comprises a multi-source noise collector, a temperature control accelerator, a noise temperature coupling analyzer and an acceleration decision master control unit. The multi-source noise collector is deployed on the surface of the acceleration unit and an internal key node, and captures an electromagnetic radiation noise spectrum and a mechanical vibration noise waveform in real time; the temperature control accelerator integrates a thermoelectric refrigeration array and a voltage frequency modulation module, receives the temperature sensing data flow, and generates a pulse type refrigeration instruction and clock frequency correction according to a dynamic strategy; the coupling analyzer decomposes the multi-modal noise signal, extracts an energy feature vector, and constructs a coupling coefficient matrix; and after receiving the matrix operation, the acceleration decision-making unit outputs a frequency scaling factor and a voltage offset to the temperature control accelerator, feeds back a failure frequency band marking result update coefficient, and combines noise and temperature coupling characteristics to realize dynamic balance of hardware acceleration performance and stability.
Owner:百信信息技术有限公司

Low power receiver with intermediate frequency (IF) detection and local oscillator (LO) frequency correction

A method, system, and apparatus for a wireless receiver with intermediate frequency (IF) detection and local oscillator (LO) frequency correction is disclosed. According to one aspect, the wireless receiver is configured to include a LO configured to generate a local oscillator signal, the LO not being phase-locked. The wireless receiver includes a mixer configured to mix the LO signal with an amplitude shift keying (ASK) modulated signal to produce an intermediate frequency (IF) signal. The wireless receiver also includes a tuning circuit configured to estimate a frequency of the IF signal and tune the LO according to the estimated intermediate frequency, and tune the LO to compensate for IF frequency drift. The IF frequency estimation is based on a correlation of the signal in a plurality of frequency bins of a fast Fourier transform (FFT) of the IF signal.
Owner:TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

Synchronous phasor calculation method and system suitable for power grid transient fault analysis

The embodiment of the invention provides a synchronous phasor calculation method and system suitable for power grid transient fault analysis, and the method comprises the steps: collecting three-phase voltage and current signals at a fixed sampling interval, and constructing a data window with the length of N; a synchronous phasor is calculated based on a data window by adopting a cyclic DFT algorithm, and frequency correction is performed through a three-point frequency correction method; monitoring the abrupt change rate of the zero-sequence component in real time to identify the power grid operation state; when the operating state of the power grid is identified as a fault, performing fault phasor calculation by using a short data window by adopting a least square method based on an attenuation direct-current component model; and outputting a phasor result according to the power grid operation state. According to the technical scheme provided by the invention, the precision, the real-time performance and the robustness of phasor analysis in the transient fault process of the power grid can be improved.
Owner:STATE GRID JIANGSU ECONOMIC RES INST

Distortion-resistant distributed optical fiber sensing method and system based on array phase spectrum demodulation

The invention belongs to the technical field of distributed optical fiber sensing, and relates to an anti-distortion distributed optical fiber sensing method and system based on array phase spectrum demodulation, an ultra-weak reflection optical fiber Bragg grating array is used as a sensing optical fiber, a series of reflection peaks with the signal-to-noise ratio higher than that of RBS are generated, a reflection peak sequence is formed, and the beat frequency signal spectrum amplitude is increased. A discrete beat frequency signal with frequency domain distortion output by an OFDR sensing system is converted to a frequency domain through Fourier transform of a symmetric window function to obtain a corresponding discrete frequency spectrum, and characteristic parameters such as amplitude and phase of a reflection peak sequence in the frequency spectrum are tracked and extracted; and then frequency correction factors of the reflection peak sequence in all measurement periods are calculated by using an amplitude interpolation correction method to obtain a corrected accurate array phase spectrum, and phase difference and strain calculation are performed to realize multi-point quasi-distributed strain demodulation for suppressing frequency domain distortion such as Doppler frequency shift and the like. The frequency resolution limitation caused by the fence effect is broken, and the fidelity of the frequency domain distortion signal is recovered.
Owner:BEIJING INST OF TECH

Anti-unmanned aerial vehicle passive positioning method and system based on low-orbit satellite external radiation source

The invention provides an anti-unmanned aerial vehicle passive positioning method and system based on an external radiation source of a low-orbit satellite, and relates to the technical field of satellite positioning, and the method comprises the steps: employing the external radiation source of the low-orbit satellite as an irradiation signal source under the same time reference, and carrying out the irradiation of each ground receiving station, performing synchronous sampling on the complex sampling sequences corresponding to the reference receiving channel and the monitoring receiving channel, performing frequency correction and phase correction on the complex sampling sequences of the reference receiving channel and the monitoring receiving channel, and performing feature comparison on the complex sampling sequence of the reference receiving channel and a historical robust complex sampling sequence; and obtaining a feature comparison result, and based on the feature comparison result, updating a background reference value used for delay-frequency shift image background normalization and a background reference value allowable fluctuation interval, so that the effectiveness of multi-station observation consistency constraint can be improved, a more stable unmanned aerial vehicle position solution can be obtained, and thus anti-unmanned aerial vehicle passive positioning is realized.
Owner:YANTAI XINFEI INTELLIGENT SYST CO LTD

Multi-motor pulse speed regulation control method and system

The application provides a multi-motor pulse speed regulation control method and system, relates to the technical field of motor control, and acquires a target setting quantity and a target motor identifier, converts a target driving parameter according to a parameter set associated with the target motor identifier, the parameter set including an elastic modulus value and a stress relaxation coefficient of a peristaltic pump hose; real-time driving parameters are maintained for multiple pulse output channels respectively and are refreshed at a synchronous time; operation state feedback values of the peristaltic pump channel and the stirring motor channel are collected, a water hammer effect frequency component and an impeller passing frequency component are extracted, and correction is carried out based on the elastic parameters; it is judged whether a cross-channel resonance judgment condition is met, when the condition is met, a frequency correction amount and a phase correction amount are determined and are applied to at least one pulse output channel, so that the resonance risk is reduced and the system operation is stabilized.
Owner:SHANGHAI BAOXING BIOLOGY EQUIP ENG CO LTD

Methods for Synchronization in a Non-Terrestrial Network

Methods are described for synchronization in a non-terrestrial network. A satellite communication terminal may receive, over its satellite link, synchronization transmissions containing one or more synchronization signals. The synchronization transmission may be received with an unknown frequency offset and / or at very low signal-to-noise ratio, and / or the synchronization signals may be formatted in any of several predefined patterns, making detection and / or demodulation of the one or more synchronization signals a challenge. According to the methods described herein, detection of at least one synchronization signal may include about simultaneous correlation in 3 dimensions of multiple instances of the at least one synchronization signal. The correlation result may then be used for generating a fine-resolution frequency correction, once applied demodulation of one or more additional synchronization signals and extraction of network access information becomes possible.
Owner:GILAT SATELLITE NETWORKS

Discharge sound source positioning method based on frequency correction

The invention relates to a discharge sound source positioning method and device based on frequency correction, computer equipment, a computer readable storage medium and a computer program product, and can be applied to the technical field of computers. The method comprises the following steps: acquiring discharge sound signals of a to-be-positioned discharge sound source received by a plurality of microphones, and performing unilateral Fourier filtering processing on the discharge sound signals to obtain filtered signals; constructing an observation model containing a frequency error term according to the filtered signal; determining joint probability distribution information based on the observation model and a noise model, a signal model and a frequency error model which are constructed in advance; using an expectation maximization model to carry out iterative calculation to obtain a sound source signal mean value in the joint probability distribution information; determining the signal energy amplitude of each point on the space grid according to the sound source signal mean value obtained by the latest iterative calculation; and determining the discharge sound source position of the discharge sound source to be positioned according to the signal energy amplitude. By adopting the method, the discharge sound source positioning efficiency can be improved.
Owner:MAINTENANCE & TEST CENTRE CSG EHV POWER TRANSMISSION CO

Islanded microgrid distributed adaptive frequency modulation method and system thereof

This invention discloses a distributed adaptive frequency regulation method for isolated microgrids. The method is executed collaboratively by each distributed power generation unit. First, it monitors the system frequency and its own status in real time to determine frequency regulation needs, and dynamically activates or suspends its frequency regulation participation status through an event-triggered mechanism. The activated frequency regulation participating units calculate dynamic weighting coefficients based on the frequency deviation direction, combined with equipment type, power generation stability, reserve power utilization rate, and operating costs. Then, it exchanges information with neighboring units through a sparse communication network, runs an adaptive distributed consensus algorithm based on the dynamic weights, and generates frequency recovery and power allocation control signals. After integration, a reference frequency correction is obtained, and the traditional droop control is corrected in real time to adjust the unit output. This invention can achieve dynamic adaptive allocation of frequency regulation priorities, reduce communication burden, quickly restore system frequency, and improve the stability and economy of isolated microgrid operation.
Owner:FUZHOU UNIV