319 results about "Frequency drift" patented technology

The invention provides a high-precision five-axis rotary table cooperative control method and system based on multi-closed-loop feedback, and the method comprises the steps: obtaining a real-time acceleration signal of a five-axis rotary table, carrying out the spectrum analysis of the acceleration signal, determining a current resonant frequency drift range and a main frequency component, and carrying out the frequency spectrum analysis; dynamically simulating the turntable structure by adopting a pre-established finite element model, and predicting the vibration mode change trend of the structure by comparing the deviation between the modal frequency obtained by simulation and the actually measured signal spectrum; according to the vibration mode change trend, matching similar vibration mode modes from a pre-established rotary table vibration mode database, obtaining corresponding vibration energy transmission path distribution, and determining an energy transmission abnormal region by analyzing the distribution of energy on each transmission path to obtain vibration energy transmission characteristics; according to an optimized motion instruction of a five-axis turntable, the dynamic response of the turntable is estimated, vibration frequency domain characteristics are extracted, and frequency domain compensation parameters are generated in combination with a preset frequency domain error matrix.

The invention relates to the technical field of semiconductors, and discloses a full-temperature-zone polynomial digital temperature compensation method and system based on an SOI chip, and the method comprises the steps: obtaining the temperature frequency data of a preset temperature zone of a target SOI chip, fitting a full-temperature-zone curve, extracting a critical point of the temperature zone, dividing a segmented compensation interval according to the critical point, and obtaining the temperature frequency data of the preset temperature zone of the target SOI chip; the method comprises the following steps: calculating frequency drift amounts under different voltages to construct a full-automatic test framework, acquiring an environment temperature parameter and an instantaneous temperature value by using the framework, analyzing a temperature compensation vector of a segmented compensation interval, further monitoring a signal frequency interval output by a chip, extracting a phase noise parameter, calculating a frequency offset error amount with a preset value, and calculating the frequency offset error amount. And analyzing an error source, optimizing a polynomial compensation order, and collecting temperature drift suppression data to generate a full temperature region compensation report. According to the invention, the performance stability of the chip in a complex environment can be improved.

The invention relates to an electrostatic vibrating diaphragm automobile audio which is mainly used for an electric vehicle and can compensate vehicle-mounted electromagnetic interference audio and solve the problem of electromagnetic interference of a motor PWM switch and rotating speed harmonics on an audio system. The electrostatic diaphragm automobile sound system comprises an electrostatic diaphragm loudspeaker and an interference feature extraction module, the rotating speed of a motor and the PWM frequency are obtained through a CAN bus, and a dynamic interference feature set is analyzed and extracted through adaptive window length FFT; the EMI quantification module is used for calculating an electromagnetic pollution index at a frequency band of 8kHz-20kHz, and triggering compensation when the electromagnetic pollution index exceeds a threshold value of-40dB; the dynamic notch compensation module is used for generating an inversion signal; according to the double-loop feedback control module, the amplitude is adjusted through PID of an inner loop, and the phase is optimized through gradient descent of an outer loop so as to minimize THD. The method comprises five steps of signal acquisition, feature extraction, interference quantification, dynamic compensation and signal injection. Interference frequency drift can be accurately tracked, a tone quality MOS value is improved after compensation, and an over-compensation risk is avoided.

The invention discloses a distributed OFDR sensing signal demodulation method and system based on local ridge line tracking, relates to the technical field of optical fiber sensing, and is used for solving the problem that a traditional cross-correlation algorithm is difficult to consider robustness and real-time performance at the same time. The method comprises the following steps: respectively processing a reference beat frequency signal of a sensing optical fiber to be measured in a strain-free state and a measurement beat frequency signal of the sensing optical fiber to be measured in a strain state to obtain a reference complex Rayleigh scattering signal and a measurement complex Rayleigh scattering signal containing a plurality of sensing positions along the optical fiber; calculating a cross-correlation function based on the two signals; stacking the cross-correlation functions corresponding to all sensing positions along a distance domain, and constructing a two-dimensional cross-correlation thermodynamic diagram matrix; performing filtering processing and weighting processing on the two-dimensional cross-correlation thermodynamic diagram matrix to obtain an optimal frequency drift distance; and demodulating based on the optimal frequency drift amount to obtain strain distributed along the to-be-measured sensing optical fiber. According to the invention, high-robustness and rapid demodulation of the signal in an application scene with extremely high real-time requirement can be realized.

The invention discloses an unmanned aerial vehicle data link communication system for beyond-visual-range cluster measurement and control, and relates to the field of communication transmission. The system comprises a dynamic topology construction module which constructs a dynamic network topology according to unmanned aerial vehicle node parameters and selects an optimal communication path; the spectrum resource management module is used for optimizing spectrum allocation of multiple frequency bands and dynamically allocating spectrum resources; the relay node selection module is used for selecting an optimal relay node and optimizing the energy consumption and the signal quality of the relay node; the clock synchronization module is used for performing high-precision clock synchronization through clock skew modeling and correcting frequency drift; the channel distribution module is used for dynamically distributing communication channels; and the fault detection module monitors the fault state of the communication link of the unmanned aerial vehicle in real time through a fault monitoring model, and performs anomaly detection. Through dynamic topology construction, intelligent relay node selection and multi-dimensional utility function optimization, the flexibility, stability and resource allocation efficiency of a communication network are effectively improved, and efficient and reliable communication of an unmanned aerial vehicle cluster is ensured.

The invention relates to the technical field of anti-seismic performance detection, in particular to an anti-seismic performance detection method and system for an assembled steel-wood composite structure, and the method comprises the steps: arranging a multidirectional acoustic emission sensor in a steel-wood structure node area, applying simulated seismic vibration, and synchronously collecting acoustic emission signals; the method comprises the following steps: preprocessing collected acoustic emission signals, dividing the acoustic emission signals into signals corresponding to microcracks and contact slippage, respectively calculating an energy attenuation rate and a phase offset, and constructing a matrix; micro-impact is applied to the steel-wood node through an electromagnetic excitation device, a response signal is collected, resonant frequency is extracted, the drift distance between the resonant frequency and a reference value is calculated, and the severity of interface damage is determined according to the value of the drift distance; the damage correlation index calculation takes the characteristic value of the interface wave propagation characteristic matrix and the resonance frequency drift distance as input, the damage correlation index is calculated through the correlation coefficient, and the damage grade is divided according to the correlation coefficient. And differential characterization of different damage types is realized through the interface wave propagation characteristic matrix.

The invention discloses a multi-channel clock buffer test system and method, and relates to the technical field of electronic testing, and the method comprises the steps: collecting an original waveform data set, synchronizing a unified reference baseline, and generating a clock output data stream; performing frequency domain transformation on the clock output data stream, extracting dominant frequency drift, harmonic intensity change and phase fluctuation, and generating a spectrum disturbance feature vector sequence; performing recursive estimation on the spectrum disturbance feature vector sequence by using a Kalman filter, correcting state distribution in combination with a Bayesian probability updating method, and generating a health score drift trend vector; and performing multi-scale comparison on the health score drift trend vector, and identifying a channel entering a sub-health area by using an abnormal drift acceleration factor to generate an abnormal channel feature data set. According to the method, complex association between historical failure modes and features is mastered through the training time sequence prediction network, potential health score changes and failure time in the future are effectively predicted, and early warning is achieved.

The invention discloses an audio and video acquisition synchronous management method, and relates to the technical field of data synchronization. The method is executed by main control equipment and comprises the following steps: S1, acquiring a satellite time reference through a dual-mode time service module; s2, based on the pulse signal of the temperature compensated crystal oscillator, a master clock signal is generated according to a formula Tmaster = TGPS + alpha delta T + beta (delta f / f0), TGPS is a satellite time reference, alpha is a temperature compensation coefficient and ranges from 0.2 to 0.8, and beta is a frequency drift correction factor; s3, establishing an inter-device time synchronization communication link through an IEEE 1588PTP protocol, and broadcasting a synchronization pulse by the main control device; s4, the data buffer area is adjusted in real time according to the dynamic buffer control formula D (t) = D0 + k1 * (delta t) 2 + k2 * d delta t / dt, k1 = 0.15 ms-2, and k2 = 2.5 ms2 / s; s5, when the network time delay gt is detected; and at 150ms, switching to a local clock compensation mode, and triggering the extended Kalman filter to re-correct the clock parameters. According to the invention, a hybrid synchronization architecture with local clock correction capability is constructed, and self-adaptive time difference compensation without network dependence is realized.

The invention discloses a radio frequency chip heat effect compensation system and method based on multi-physics field coupling, the system comprises a radio frequency chip body, a multi-physics field coupling calculation module, a temperature sensor array and a dynamic compensation algorithm module, and the method comprises the following steps: evaluating frequency deviation caused by a heat effect; collecting multi-point temperature data and converting the multi-point temperature data into frequency drift data; regional temperature regulation and control are executed through a temperature control array, and frequency drift is eliminated. The compensation effect is evaluated in real time, and compensation parameters are dynamically optimized. According to the invention, predictive compensation of frequency drift is realized, the compensation precision is improved by 2-3 times, and the response speed is improved by 5-10 times; the system has self-adaption and self-learning capabilities and can adapt to rapid temperature change as high as 0.5 DEG C / s, and the technical breakthrough that the system is more and more accurate is realized; while the performance is greatly improved, the frequency stability reaches 10 <-8 > magnitude, the phase noise is reduced by 12 dBc / Hz, the power is saved by more than 80%, the area is increased by less than 2 mm < 2 >, and the technical contradiction of high performance and inevitable high power consumption is solved.

The invention discloses a data processing method and system of a chromatographic instrument, and relates to the technical field of data processing, and the method comprises the following steps: collecting whole-course original detection signals and external interference signs generated in a chromatographic analysis process, carrying out time alignment under a unified time scale, generating an interference rhythm index, and calculating the interference rhythm index; the reference is used as a unified reference for subsequent signal comparison; and based on the interference rhythm index, performing phase drift comparison on the acquired signal, calculating the phase difference between the detection signal and the interference signal, drawing a beat frequency wandering graph, extracting candidate signal segments of pseudo-period interference according to beat frequency change, and generating a pseudo-period candidate segment list. According to the invention, by establishing the interference rhythm index and comparing the interference rhythm index with the phase drift, the time decoupling of the detection signal and the interference signal is realized, and the sampling anti-interference capability is improved; and through dynamic control of a false peak characteristic fingerprint draft and a misjudgment reason table, signal rhythm correction and peak identification optimization are completed, so that the detection accuracy and the data stability are improved.

The invention relates to the field of sensor data processing, and discloses an MEMS drift correction method based on data dynamic sampling and multi-source fusion, and the method comprises the following steps: S1, collecting MEMS three-axis acceleration original data at a first sampling frequency, and synchronously collecting environment temperature, humidity and air pressure data at a second sampling frequency, the first sampling frequency is higher than the second sampling frequency, the basic drift correction model is established by using the low-frequency data to capture the macroscopic and slow-varying relationship between the environmental factors and the drift, then the residual refinement model is established for the high-frequency data, and the high-frequency residual is specially processed; high-frequency drift components related to the environmental change rate are captured, through the two-stage fusion strategy, the accuracy of the model in the macroscopic trend is guaranteed, high-frequency data are fully utilized to improve the instantaneous correction precision, information loss caused by simple downsampling in a traditional method is avoided, and false signals introduced by rough interpolation are also avoided.

The invention discloses a remote monitoring system for a numerical control bearing processing machine tool, belongs to the technical field of machine tools, and solves the problems that during finish turning of a GCr15 thin-wall ferrule, a main shaft pretightening force is attenuated to cause inherent frequency drift, servo parameters just fall on an excitation band, cutting force induces high-frequency flutter, fish scale vibration marks are generated, the service life and noise of a bearing exceed the standard, batch reworking is carried out, and machining efficiency is high. And the precision of a machine tool is permanently damaged. Comprising a multi-source information sensing module, a causal discovery and decision center, a dynamic stiffness field regulation and control module and a real-time simulation verification module, wherein a fiber bragg grating demodulator of the multi-source information sensing module is connected to a main shaft bearing seat in a machine tool through a sensing interface; a laser Doppler vibration meter of the multi-source information sensing module is in butt joint with a tool-workpiece machining area in a machine tool through an optical probe. Pre-tightening-servo-cutting coupling is sensed in real time, the magneto-rheological rigidity is actively adjusted, resonance is avoided, flutter is restrained and eliminated, high-frequency flutter is immune in advance, chatter marks and batch accidents are eradicated, and a cutter machine tool is protected.

The invention discloses a power grid time frequency change trend prediction method and system based on intelligent electric meter data fusion, and the method comprises the steps: measuring the network transmission delay and time deviation between a master clock and a slave clock of a power grid, obtaining an initial time frequency deviation sequence, carrying out the error calibration, carrying out the data fusion after time domain alignment, and carrying out the prediction of the time frequency change trend. Generating a fusion time sequence; performing recursive estimation on the fusion time sequence, outputting an optimal time frequency deviation sequence, and performing synchronous estimation to obtain a clock phase error, a frequency error and frequency drift as state characteristic quantities; and training a preset machine learning prediction model by taking the optimal time frequency deviation sequence as a supervision signal and taking the state characteristic quantity of the corresponding moment as input, and obtaining a prediction result of the power grid time frequency change trend in the future period based on the trained time frequency change trend prediction model. According to the method, the power grid time synchronization precision and prediction capability are remarkably improved, and reliable technical guarantee is provided for stable operation of a power system.

The invention provides a power transmission line operation risk prediction method based on big data mining, and the method comprises the steps: collecting the high-frequency vibration data and environment parameters of a bolt connection part of a power transmission line tower in real time, and generating a time sequence data set containing the vibration frequency, the amplitude and the temperature; a Fourier transform algorithm is adopted for the time sequence data set, a dominant frequency component of the vibration frequency is extracted, linear correction is conducted on the vibration frequency according to the thermal expansion coefficient and the temperature of the bolt material, and a frequency feature set is generated; constructing a bolt state evaluation model according to the preliminary feature set and the stress distribution feature set, evaluating the bolt state, and outputting the bolt pre-tightening force attenuation degree; and according to the state score of each bolt output by the optimized state evaluation model, calculating the overall load sharing and vibration frequency drift degree of the bolt joint, and generating a load sharing feature set.

The invention discloses a low-cost precise time keeping method, system and device based on a gating circulation unit, and relates to the technical field of power grid measurement. The method is executed when the synchronous phasor measurement device cannot receive external signals, and comprises the following steps: monitoring operation parameters which influence the frequency stability of an internal crystal oscillator of the phasor measurement unit in real time; calculating a current frequency error of the crystal oscillator in real time by using a crystal oscillator frequency drift prediction model based on a gated cycle unit network based on the operation parameters; generating a time correction amount according to the current frequency error; and applying the time correction to a local clock of the phasor measurement unit to compensate the frequency drift of the crystal oscillator so as to realize accurate time keeping. According to the invention, through accurate prediction of crystal oscillator errors and lightweight software compensation, the synchronous phasor measurement device adopting a low-cost crystal oscillator can also realize long-time high-precision time keeping, the hardware cost is obviously reduced, and the reliability of power grid monitoring during the Beidou / GPS lock losing period is improved.

The invention discloses a modularized hydraulic system testing system and method, and relates to the technical field of hydraulic testing, and the method comprises the following steps: S1, collecting outlet pulsating pressure signals of a high-pressure plunger pump and a low-pressure vane pump by adopting a nanosecond-level synchronous time mark system, generating a phase residual error map, and calculating a phase residual error map of the outlet pulsating pressure signals of the high-pressure plunger pump and the low-pressure vane pump; the hidden resonance risk is preliminarily judged through frequency drift and amplitude gradient calculation; and S2, on the basis of the synchronous acquisition base line, carrying out cross spectrum coherence degree calculation and phase difference time sequence analysis on the pulsating pressure sequence, identifying a frequency dislocation anchor point, generating a pump source pulsating interference fingerprint, and determining a time window of recessive resonance. According to the method, real-time identification, dynamic intervention and closed-loop control of recessive resonance in the hydraulic system are realized through nanosecond-level synchronous acquisition, phase conjugate inversion and frequency dislocation traction strategies, energy coupling caused by frequency dislocation is effectively avoided, the operation stability and safety of the system are improved, and the service life of equipment is prolonged.

The invention discloses a Beidou PTP master clock device based on chip atomic clock timekeeping, which integrates a chip atomic clock and a Beidou satellite time service signal, and comprises the following steps: firstly, receiving a Beidou satellite signal through a satellite receiving module, and generating an accurate 1PPS signal, a TOD signal and a 10MHz frequency signal based on the satellite signal; high-precision time-frequency reference is provided for equipment, and the problem that clock precision is insufficient in a traditional clock synchronization system is solved through the design. Secondly, the first clock board and the second clock board carry chip atomic clocks, and the high stability and low power consumption characteristics of the chip atomic clocks enable the equipment to maintain high precision of clock signals during long-time operation, so that clock errors caused by crystal oscillator frequency drift and aging in a traditional system are avoided. Moreover, the communication core board is connected with the upper computer, so that instructions can be received in real time, and the clock board and the logic control board can be controlled to work, and therefore, the system can quickly respond to the instructions of the upper computer, and accurate time control can be realized.

The invention discloses a power distribution area energy storage-photovoltaic oscillation cooperative suppression method based on impedance remodeling, and belongs to the technical field of power system stability control. According to the method, the impedance characteristic of the system is scanned online in real time, the virtual impedance controller parameters of the photovoltaic inverter are dynamically optimized, and the impedance frequency characteristic of the zone area network is actively remodeled, so that the zone area network is always far away from a stable critical point, and oscillation is prevented from occurring from the source. When it is detected that the oscillation energy exceeds the standard, the system immediately triggers the energy storage device to be switched to a virtual synchronous generator mode, phase information of a plurality of energy storage units in a fiber channel synchronization cluster is used, anti-phase damping current opposite to the oscillation trend is injected, and the oscillation energy is rapidly consumed. The invention provides a double-layer suppression strategy based on impedance remodeling and energy storage cooperation, the cooperation of photovoltaic impedance active prevention and energy storage instantaneous suppression is realized, the problem that a traditional fixed parameter damper loses efficacy due to frequency drift is solved, and the operation stability of a high-proportion renewable energy power distribution network is improved.

The invention belongs to the technical field of laser precision machining and control, and particularly relates to a femtosecond laser single-point trigger control system and method based on subnanosecond synchronization, and the method comprises the following steps: S1, building a system synchronization clock locked with a femtosecond laser pulse signal phase; the specific mode of establishing the system synchronous clock is that phase locking is carried out on pulse synchronous signals or frequency division signals output by an internal high-frequency clock source and a femtosecond laser source through a digital phase-locked loop technology, and the low-jitter system synchronous clock which is strictly synchronous with a laser pulse sequence is generated. According to the invention, a system clock locked with a laser pulse phase can be generated through a digital phase-locked loop, and the influence of inherent frequency drift of a laser and circuit delay temperature drift is effectively overcome by combining real-time delay calculation based on a prediction algorithm and a high-resolution DDS delay line technology; the synchronization precision between the triggering moment of the single pulse and the external instruction is stabilized at the subnanosecond level, and the requirement of leading-edge application for the extreme time sequence precision is met.

Embodiments of the present disclosure provide a method and an apparatus for monitoring a system clock signal. The apparatus comprises: a toggle detector configured to monitor whether the system clock signal is toggling; an abnormal pulse detector configured to, in response to the system clock signal being toggling, utilize a reference clock signal to count the number of periods of the system clock signal within a predetermined time limit and monitor whether the number of periods is beyond a predetermined range, the reference clock signal having a frequency higher than the system clock signal; and a frequency drift detector configured to, in response to the system clock signal being toggling, detect a phase error between the system clock signal and a delay clock signal delayed from the system clock signal, determine a frequency drift based on the phase error, and monitor whether the frequency drift exceeds a predetermined drift limit.

The invention provides a water supply pipe network leakage detection method and device based on an accelerometer and a readable storage medium thereof, and belongs to the technical field of pipe network detection. The method comprises the following steps: acquiring an original acceleration signal; the acceleration signal is accurately converted into a displacement vibration signal by adopting double-order integral drift suppression processing so as to overcome low-frequency drift; carrying out time-frequency analysis on the displacement signal, and extracting transverse characteristics representing the physical nature of leakage; the transverse characteristic is characterized based on three dimensions of time continuity, frequency broadband and amplitude stability; a self-adaptive threshold value is adopted to judge the transverse characteristics, and the threshold value is dynamically generated according to real-time background noise characteristics; and finally, multi-dimensional comprehensive judgment can be carried out by combining time domain auxiliary conditions such as a peak factor and a zero-crossing rate, and a leakage result is determined. The problems of integral drift, inaccurate feature extraction and poor robustness are solved, and low-cost, high-precision and low-false-alarm leakage detection is realized.

The invention relates to the technical field of radio orientation, and discloses an unmanned aerial vehicle radio frequency countering monitoring system based on multi-source signal state perception, and the system comprises a radio frequency collection subsystem which employs a dual-channel common-source difference mechanism to synchronously collect target and reference signals; the state synchronous bus obtains a motion state vector of the unmanned aerial vehicle; and the virtual aperture synthesis processor calculates an instantaneous phase difference between channels to offset local frequency drift, generates a correction phase sequence, constructs a virtual antenna array model in combination with a motion trail, and solves a target space incident angle. And high-precision direction finding of long-wave signals is realized on a small platform.

The invention provides a resonance control method for an excimer lamp driven by a steep pulse edge, and relates to the technical field of molecular lamps. The resonance control method of the excimer lamp driven by the steep pulse edge comprises the following steps: S1, based on a dielectric barrier discharge equivalent circuit model, adopting a fast Fourier transform spectrum analysis method, measuring fundamental wave impedance characteristics of an LC resonance network through an impedance analyzer, establishing a transfer function containing parasitic parameters: Z (s) = [sLr + 1 / (sCr)] Rarc, and generating an initial resonance parameter set; by establishing a transfer function model containing parasitic parameters, combining fast Fourier transform spectrum analysis and accurately extracting fundamental wave impedance characteristics, the problem of resonance point offset caused by neglecting the parasitic parameters in a traditional method is solved, the precision of an initial resonance parameter set is improved, real-time phase difference data are identified on line by using a recursive least square method, and the real-time phase difference is obtained. Resonant frequency changes are dynamically tracked, frequency drift errors are compensated, resonance point tracking precision is controlled within + / -0.1%, and invalid discharge energy loss is remarkably reduced.

The invention is suitable for the technical field of electric energy transmission, and provides an SWPT system frequency adaptive regulation and control method and system based on environmental perception, and the method comprises the steps: obtaining the output current data of high-frequency electric energy, and obtaining the first current data; determining an initial frequency disturbance step length in combination with the collected environmental parameters; applying disturbance to the output frequency according to the initial frequency disturbance step length, and collecting output current data after disturbance to obtain second current data; the change trend of the two current data is analyzed, and the deviation direction of the current working frequency and the system resonant frequency is judged; adjusting the output frequency according to a frequency control instruction generated in the deviation direction, and enabling the current working frequency to approach the resonant frequency; current data is continuously updated, and in combination with environment parameters collected in real time, the working frequency tracks resonant frequency drift caused by environment change through iteration; and the environmental adaptability, the energy transmission efficiency and the overall reliability of the single-line electric energy transmission system are effectively improved.

The invention discloses an unmanned aerial vehicle countering method and system based on multi-platform cooperation, and relates to the technical field of unmanned aerial vehicle countering, and the method comprises the steps: carrying out the data collection based on a multi-unmanned aerial vehicle platform, including radio frequency signals, radar scanning and image data; and extracting a motion feature vector, calculating instantaneous frequency drift according to instantaneous frequency fluctuation, analyzing and calculating distortion deviation through a radio frequency signal, and fitting a response curve of the power amplifier through a logarithmic power curve. According to the method, through joint characterization of constellation diagram distortion and a power amplifier response curve, the distinguishing capability of radio frequency characteristics is enhanced, the omnibearing characterization capability from signal waveform details to power degradation behaviors is provided, and through a closed-loop mechanism of coupling characteristics, abnormal point detection and position inversion, the power degradation behavior of the power amplifier is improved. The real-time performance and precision supported by the countering decision are remarkably enhanced, the abnormal analysis of sample points is directly linked to target space positioning, and target position estimation is gradually optimized.

The invention relates to the technical field of ultrasonic bonding, in particular to an ultrasonic adjusting method of a bonding system, which comprises the following steps of: acquiring voltage and displacement waveforms, analyzing a power trend, shielding a main window if a rising proportion is high and displacement exceeds a limit, extracting a maximum displacement point frequency to divide a standby window, and generating standby configuration by combining an impedance library. And monitoring peak time difference fluctuation and offset, calling configuration and matching a displacement time sequence generation instruction, monitoring displacement stability to be matched with pressure, setting a standby window as a main window if the condition is met, and generating a reconstruction mark. According to the method, the driving voltage and the transducer displacement waveform are continuously monitored, the power trend and the displacement fluctuation are analyzed in real time, the peak time difference fluctuation is synchronously monitored, the abnormal working conditions are screened to trigger the driving strategy switching, and the main frequency band is reconstructed according to the steady-state displacement characteristics. Pseudo soldering and material damage are avoided, the vibration energy utilization rate is improved, and the bonding pressure control precision and the connection strength are guaranteed.

The invention relates to the technical field of array antenna signal integrity detection, and discloses an array antenna signal integrity deception detection method and system, and the method comprises the steps: obtaining a receiving signal in an array antenna, and analyzing the quality parameter of the receiving signal; according to the quality parameter, identifying a receiving unit with inherent signal bias in the array antenna, and marking the receiving unit with inherent signal bias as a special processing unit; for a special processing unit, establishing and continuously updating a defect feature model representing inherent signal bias of the special processing unit under the condition of no deception signal; inherent signal bias is eliminated from the real-time received signals of the special processing unit based on a defect feature model, and signals after bias elimination are obtained; detecting whether an abnormal phase or frequency drift exists in the signal after the offset is eliminated; and when the detected abnormal phase or frequency drift exceeds a preset spoofing judgment threshold, determining that a spoofing attack exists. The problem that spoofing attacks are difficult to recognize is effectively solved.

The invention provides a method and equipment for testing the punctuality precision of a time synchronization device, belongs to the technical field of time frequency, and aims to solve the problems of low test automation, difficulty in quantification of environmental influence, inaccurate evaluation and high result subjectivity in the prior art. The method comprises the following steps: simulating an external signal interruption punctuality scene through a dual-channel radio frequency switch, and synchronously acquiring an output signal (time deviation data compared with a high-precision reference clock) of a time synchronization device and temperature, humidity and air pressure environment data; and analyzing the stability of the crystal oscillator through a TIE algorithm and Arron variance, and correlating modeling to quantify the environmental influence to generate a multi-dimensional evaluation report. The objective performance portrait containing parameters such as frequency drift and stability is provided, the defects of a traditional method are overcome, and a scientific basis is provided for equipment research and development optimization and model selection design.

Piezoelectric materials, particularly ones with high quality factor used for mechanical antenna implementations, are sensitive to environmental conditions including temperature swings, humidity, vibration. Under the varying environmental conditions, the resonant frequency of the piezoelectric antenna can drift, and this results in the dampened piezoelectric radiator performance due to the mismatch between RF source' excitation frequency and piezoelectric antenna's resonant frequency. The frequency drift can be detrimental to the operation of the communication system that involves piezoelectric transmitter / receiver as a system component. In embodiments, the piezoelectric antennas may be integrated into a crystal oscillator to lock a drive frequency of the piezoelectric antennas to a resonant frequency of the piezoelectric antennas.

The invention relates to a method for rapidly measuring the resonant frequency of a resonant cavity based on frequency spectrum polynomial fitting, and belongs to the technical field of acoustic / optical measurement. The objective of the invention is to solve the problems of tedious steps, low efficiency, long time, poor stability and the like of a resonant cavity or resonant photoacoustic cavity resonant frequency measurement method. According to the method, the frequency spectrum of the resonant cavity is obtained through frequency mixing excitation, the frequency is obtained after curve fitting is conducted on frequency spectrum data points through a frequency spectrum polynomial fitting algorithm, and then resonant frequency measurement of the resonant cavity is achieved. According to the method, the measurement time of the resonant frequency of the resonant cavity is remarkably shortened, the measurement steps are simplified, and the measurement precision is improved; meanwhile, the resonance frequency is solved through frequency spectrum polynomial fitting, data noise interference can be effectively reduced, and the method has higher robustness. All frequency signals within the resonant frequency drift range are transmitted at a time through frequency mixing excitation, one-by-one scanning is not needed, and therefore the method has the advantages of being good in real-time performance, high in response speed, high in precision and the like, and is suitable for rapid frequency calibration and real-time monitoring in the fields of acoustic resonators, resonant photoacoustic spectra and the like. And a novel method for measuring the resonant frequency is provided for the fields of high-sensitivity resonance photoacoustic spectroscopy, acoustic trace gas detection and the like.