320 results about "Frequency measurements" patented technology

A frequency measurement method performed by a user equipment (UE) in a wireless communication system is provided. The frequency measurement method includes: receiving a radio resource control (RRC) release message or system information including first frequency measurement configuration information for frequency measurement in an RRC inactive mode; performing frequency measurement in the RRC inactive mode based on the first frequency measurement configuration information; receiving first RRC resume message including an indicator requesting a measurement report in the RRC inactive mode; and transmitting an RRC resume complete message including the measurement report based on the indicator.

The invention provides a self-adaptive algorithm and system for improving frequency measurement precision and response speed of a speed regulator. The method comprises the following steps: Step 1, signal acquisition and preprocessing; step 2, dynamically adjusting filtering parameters, and suppressing power grid signal noise; 3, extracting frequency characteristics in real time, and improving the frequency measurement resolution; 4, a synchronous clock is adopted as a reference frequency source, a clock reference value is periodically and automatically corrected, and long-term drift is eliminated; 5, a nonlinear dynamic model of the hydroelectric generating set is constructed, the nonlinear relation between the valve opening degree and output of the speed regulator is compensated in real time, and the frequency modulation precision is improved; and step 6, outputting the instantaneous frequency. According to the scheme, through the self-adaptive frequency measurement algorithm, high-precision clock calibration, a hardware acceleration mechanism and a nonlinear compensation strategy, a multi-dimensional optimization system is constructed, high-precision frequency measurement is carried out, a rapid effect can be achieved, and a hydroelectric system has long-term stability and high adaptability.

The invention provides a microwave superheterodyne frequency sweep measurement system based on Rydberg atoms, and belongs to the technical field of microwave frequency measurement. The laser module excites detection light of 780 nm and coupling light of 480 nm, and the two beams of light are reversely input into the atomic gas chamber through the dichroscope; signal microwaves are generated by a radio frequency signal source and are radiated to the position of the atomic gas chamber through the horn antenna; local oscillation microwaves are generated by the microwave module and are also radiated to the position of the atomic gas chamber through the horn antenna; the atomic gas chamber serves as a mixer to form a difference frequency signal; the spectrum analyzer is used for monitoring low-frequency difference frequency signals generated in the frequency mixing process in real time and recording signal intensity in real time. According to the invention, high-precision and wide-band microwave frequency measurement is realized, continuous and smooth frequency sweeping response can be provided in a frequency range, and absolute frequency detection of microwave signals is realized under the condition that a complex frequency comb technology is not introduced. The hardware architecture is simplified, the automation degree is improved, and integration, popularization and application are facilitated.

The invention discloses a frequency measurement circuit and a frequency measurement method, belongs to the technical field of frequency measurement, and mainly solves the problems that the existing frequency measurement is large in frequency error, low in frequency measurement speed and narrow in frequency measurement bandwidth, and cannot meet the requirements of radar communication. The frequency measurement circuit comprises an FPGA control module, a reference clock circuit connected with the FPGA control module, a DDS frequency output circuit, a phase discrimination frequency control circuit, a frequency mixer connected with the phase discrimination frequency control circuit, and a radio frequency input circuit connected with the frequency mixer. According to the frequency measurement technology, the DDS output frequency is directly collected according to the characteristic that the FPGA collects the low frequency, the DDS output frequency serves as the phase discriminator phase discrimination frequency, frequency measurement is conducted in a phase locking mode, and the frequency measurement precision is high; the phase discriminator is set to have a fixed frequency dividing ratio, the phase discriminator is configured with a fixed register, a DDS frequency sweeping mode is adopted, and the frequency measurement time is short by changing the phase discrimination frequency of the phase discriminator to the output frequency of the phase-locked loop; and the frequency measurement bandwidth is increased by using a radio frequency input frequency division mode.

The invention provides a frequency conversion sampling system and method, and relates to the technical field of electric power measurement, the system comprises a frequency measurement module, a clock generator module, an ADC module and a main control module, the frequency measurement module converts a measured AC signal into a target level signal; the main control module determines the current frequency of the detected AC signal based on the target level signal, and sends a frequency adjustment instruction to the clock generator module when the current frequency is different from the original frequency; the clock generator module provides a clock signal for the ADC module so as to drive the ADC module to sample according to a sampling frequency, and the sampling frequency is equal to a preset multiple of a current frequency; the ADC module performs voltage sampling and current sampling on the detected alternating current signal according to the sampling frequency to obtain a first digital signal and a second digital signal, and transmits the first digital signal and the second digital signal to the main control module; the main control module calculates a group of electrical parameters of the detected AC signal. By implementing the technical scheme provided by the invention, the measurement accuracy can be effectively improved.

The invention provides a measurement method and device, and the method comprises the steps: receiving first configuration information, the first configuration information comprises first information and second information, the first information is used for indicating the length of each first measurement gap in at least two first measurement gaps, and the at least two first measurement gaps are located in a first measurement period; two adjacent first measurement gaps in the at least two first measurement gaps have an interval in the time domain, and the second information is used for indicating the starting time of each first measurement gap in the at least two first measurement gaps; and performing pilot frequency measurement on the at least two first measurement gaps. According to the measurement method and device provided by the embodiment of the invention, the conflict between the measurement time and the service data transmission time can be reduced.

The invention belongs to the technical field of optical frequency comb repetition frequency, and discloses an optical frequency comb repetition frequency control system and a locking method, and the system comprises a light source module, a signal detection module, a frequency measurement module, a comparison frequency generation module and a feedback control module. The light source module generates an optical frequency comb; the signal detection module converts the optical signal into an electric signal, noise reduction and amplification processing are carried out through a signal processor, and noise reduction adopts a wavelet transform method; the frequency measurement module adopts a dual measurement mode of a frequency counter and a spectrum analyzer to accurately measure repetition frequency; the comparison frequency generation module provides high-precision reference frequency; and the feedback control module performs closed-loop adjustment according to the difference value between the measurement frequency and the reference frequency. By optimizing signal processing and adopting dual-frequency measurement and closed-loop feedback control, the problems of weak electric signals, large noise interference and low frequency control precision in the prior art are effectively solved, and the stability and accuracy of the repetition frequency of the optical frequency comb are improved.

The invention provides an inter-satellite link bidirectional measurement method based on a same-time same-frequency full-duplex system, which overcomes the problem that receiving and transmitting of a traditional time-division half-duplex system cannot work at the same time and at the same frequency, and can effectively improve the information transmission rate and the ranging precision. The inter-satellite transmission rate, the measurement frequency and the data updating rate can be doubled; simultaneous and same-frequency measurement between satellites can greatly eliminate distance measurement errors caused by relative motion between satellites, clock skew and Doppler effect; a complex orbit model does not need to be established to improve the distance measurement precision, the time scale reduction error is greatly reduced, and the overall measurement performance is improved.

The invention discloses a frequency sweep measurement method and system. The method comprises the following steps: acquiring a fundamental frequency reference phase of each measured equipment access point at a measurement moment; executing rough scanning of the first-stage injection; analyzing the coarse scanning response data to identify a target frequency band which needs to be subjected to second preset resolution measurement; executing fine scanning of second-stage injection for the target frequency band; and analyzing the fine scanning response data, and obtaining a stability contribution evaluation result of each tested device to the power grid system based on an analysis result of the fine scanning response data and an analysis result of the coarse scanning response data. According to the scheme of the invention, the method can achieve the quick recognition of the potential key frequency region in a broadband range through the hierarchical rough scanning and fine scanning strategies, and avoids the time-consuming high-resolution measurement in a whole frequency band. And then, high-resolution fine scanning is performed on the identified target frequency bands in a targeted manner, so that accurate and detailed response data can be obtained in the key region.

The invention relates to the field of power grid monitoring, in particular to a frequency measurement method and terminal for power grid monitoring, and the method comprises the steps: enabling a current sequence, a voltage sequence, a frequency sequence and a temperature sequence collected by the power grid frequency measurement terminal to pass through a temperature prediction model of a physical constraint neural network architecture, so as to generate a temperature prediction value; constructing a differential algebraic constraint term based on a current sequence change rate, a frequency sequence acceleration, a temperature sequence change rate and a temperature prediction value and an energy conservation term based on electromagnetic energy calculation for optimizing and training a temperature prediction model; and calculating a frequency temperature drift value based on the temperature prediction value, and correcting a frequency acquisition value of the power grid according to the frequency temperature drift value. The frequency measurement error caused by the temperature drift effect of the power grid in the high-temperature environment can be counteracted in real time, and the temperature drift suppression capability of power grid monitoring frequency measurement is improved.

The invention discloses a self-adaptive large dynamic detection noise floor suppression system and a control method thereof. The system comprises a filtering selection front-end module, a detection synthesis module, a frequency measurement receiving module and an FPGA feedback control module. The method is composed of four main parts, namely a filtering selection front end, detection synthesis, frequency measurement receiving and FPGA feedback control. Wherein the filtering selection front end and the frequency measurement receiving end receive two groups of external radio frequency signals at the same time. And frequency measurement is carried out through a mature single-bit receiving scheme in frequency measurement receiving, and a result is sent to the feedback control module, so that switching of a filtering channel and suppression of a noise floor are realized. According to the invention, the broadband large dynamic DLVA detection sensitivity is obviously improved.

The invention discloses a system reference clock frequency accuracy automatic calibration circuit and a calibration method thereof, and belongs to the technical field of frequency sources, the calibration circuit comprises a first crystal oscillator, a first power divider, a second power divider, a second crystal oscillator, an analog switch, a radio frequency switch, a detector, a comparator, an FPGA controller, a digital analog converter, an operational amplifier and a temperature sensor. When an external high-precision reference clock is accessed, the FPGA controller automatically switches a frequency measurement reference, performs high-precision frequency measurement on a 100MHz signal output by the first crystal oscillator, and judges whether calibration is needed or not according to frequency offset; if calibration is needed, the output voltage of the digital-to-analog converter is adjusted, the Vc end of the first crystal oscillator is controlled after operational amplification, and frequency closed-loop adjustment is achieved. According to the method, the crystal oscillator does not need to be disassembled, calibration is rapidly completed on site, and system availability and long-term frequency stability are remarkably improved.

The present disclosure provides a measurement configuration method and apparatus, a device, and a storage medium, and relates to the field of communication technology. The method includes: determining, in response to that an inter-frequency measurement is to be performed on a to-be-measured inter-frequency reference signal, whether the to-be-measured inter-frequency reference signal is to be measured based on a measurement gap.

User Equipment (UE) band capabilities are received from a UE. A set of frequency band combinations are determined for the UE based on the UE band capabilities. Each frequency band combination of the set of frequency band combinations includes a group of frequency bands, and a frequency band combination priority value. Further, one or more frequency band combinations are identified from the set of frequency band combinations based on a current frequency band of the UE and the frequency band combination priority value. The UE is configured to perform frequency measurements for a plurality of frequency bands based on the one or more identified frequency band combinations. The UE is dynamically facilitated to latch to at least one frequency band based on the frequency measurements of the plurality of frequency bands.

The invention discloses a high-precision dynamic measurement method and system for power grid frequency, and the method comprises the steps: carrying out the point-by-point filtering of an input signal, removing the noise and interference in the signal, carrying out the point-by-point analysis of the signal, and calculating the frequency value of the signal; judging the validity of the frequency value, finally judging whether the frequency is stable or not, and updating the frequency. Through cooperative work of multiple steps of signal preprocessing, frequency calculation, frequency effective value judgment and frequency updating, the problems that in the prior art, frequency measurement precision is insufficient, and adaptability to noise and frequency dynamic changes is poor are effectively solved. The method has remarkable advantages in the aspects of improving measurement precision, adapting to dynamic frequency change, suppressing noise interference, meeting real-time requirements and the like, and has wide application prospects in numerous equipment such as electric power equipment, distribution network equipment, protection equipment and the like.

The invention relates to the technical field of electronic measurement and sensing, and discloses a capacitance monitoring method and system based on a sweep frequency resonance point, and the method comprises the steps: carrying out the coarse sweeping in an initial frequency range, obtaining an impedance spectrum, and recognizing a coarse resonance interval; carrying out fine scanning in the interval and calculating an accurate resonant frequency by adopting a quadratic interpolation method; calculating a capacitance value in combination with the mapping table; and dynamically adjusting the frequency sweeping window of the next period based on the historical resonant frequency. The system comprises an excitation signal generation unit, an impedance response acquisition unit, a coarse / fine scanning control unit, a resonant frequency calculation unit, a capacitance resolving unit and a dynamic frequency window updating unit, and integrates a temperature compensation and anomaly detection mechanism. Through the two-stage frequency sweeping and self-adaptive frequency window strategy, the monitoring period is shortened to 1 / 5 or below of that of a traditional method while it is guaranteed that the resonant frequency measurement precision is superior to 0.01 Hz, and the real-time performance, stability and environmental adaptability are remarkably improved.

The invention relates to the technical field of low-power-consumption electronics, and discloses a low-power-consumption instantaneous frequency measurement system which comprises a radio-frequency signal acquisition module, a signal time-frequency conversion module, a noise floor coding module and the like. The system generates a feature tensor through time-frequency analysis of a radio frequency signal, realizes dynamic threshold fusion in combination with noise floor sparse coding, extracts a multi-scale transient frequency feature by using a pyramid convolutional neural network, dynamically suppresses noise based on a signal-to-noise ratio weight, and reconstructs a real-time spectrum distribution image. The power consumption control module can adjust the ADC sampling rate and the clock frequency of the processing unit according to the signal strength, and the power management unit adopts multi-voltage domain independent power supply. The system solves the problems of frequency measurement precision and power consumption under complex noise, is suitable for the fields of wireless communication and the like, and has the characteristics of high precision, low power consumption, high spectral resolution, visualization and intuition.

This invention proposes a rapid and non-destructive method for identifying the resonant frequency of heavy-duty mechanisms. The load-end speed curves and motor-end speed curves under closed-loop and open-loop conditions at the motor end are obtained using the speed step response method and the current step response method, respectively. By performing an FFT transform on the two speed curves, the resonance peak is obtained, allowing for rapid measurement of the structural resonant frequency and the combined resonant frequency. This method eliminates the need to purchase an additional resonance analyzer, reducing measurement costs, and avoids the damage to large, heavy-duty servo mechanisms caused by sinusoidal frequency sweep measurements. It can not only be used for rapid identification of structural resonant frequencies but also to guide the design of servo controllers.

The invention discloses a network construction type converter coefficient testing method and system based on an improved phase-locked loop, and relates to the technical field of network construction type converters. The method comprises the following steps: acquiring a frequency reference signal and a phase reference output signal of the network-forming converter through frequency control; the phase reference output signal is used for outputting a PWM control signal through voltage control, and the PWM control signal is used for controlling and outputting a three-phase voltage; frequency measurement and active power measurement are carried out by using an improved phase-locked loop according to the output three-phase voltage and the phase reference output signal, and the improved phase-locked loop is a control structure formed by replacing an original PI control link in the phase-locked loop with an integration link and a lead compensation link; and according to the frequency measurement result and the active power measurement result, calculating a network-forming converter coefficient. According to the method, the frequency and the change rate signal thereof can be quickly and accurately captured, and test results of key coefficients such as a damping coefficient and an inertia coefficient can be efficiently obtained without constructing a complex model.

The invention discloses a frequency measurement method, system and device and a computer readable storage medium, and belongs to the technical field of electricians. Acquiring a sampling value, and judging whether the sampling value is invalid or not based on the absolute value of the sampling value; determining a first frequency value based on the sampling value and the sampling frequency; determining an amplitude and a phase of a vector value of the signal based on the sampling value; determining a second frequency value according to the phase change; determining a frequency based on the first frequency value and the second frequency value; according to the frequency measurement method, system and device and the computer readable storage medium, a low-value locking technology, an extreme value anti-shake technology, a sampling zero crossing point anti-shake technology and a hysteresis frequency calculation technology are adopted, and sampling point frequency measurement and vector frequency measurement are organically combined, so that the frequency measurement precision when the signal frequency fluctuates in a large range under different working conditions is ensured; and the problem that the frequency measurement error is large when the signal frequency fluctuates in a large range is solved.

The invention relates to the technical field of signal frequency measurement, in particular to a low-frequency-band fixed square wave frequency high-precision measurement method based on a kernel clock, which is suitable for the field of embedded systems and digital signal processing, is mainly used for low-frequency and fixed-frequency-band high-precision frequency measurement, and is not a frequency meter method specially used for measuring frequency. The method is suitable for measuring the fixed output frequency in a test system and the like. According to the method, a kernel clock of an embedded system (such as an STM32 single-chip microcomputer) is mainly utilized, a time constant is calibrated by measuring the count value of the duration of high and low levels of a fixed time window, and therefore the square wave frequency is obtained through calculation.

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.

The invention discloses a method and a device for measuring sound field distribution of an ultrasonic cleaning tank, which can be used for real-time measurement of any space point sound pressure and point frequency of a liquid medium in ultrasonic cleaning equipment and can also be used for acquiring sound field distribution after interference superposition of sound pressure and frequency of any longitudinal and cross sections of the cleaning tank. Measurement signals of the sensor are subjected to impedance and amplitude adjustment, shaping, frequency band bridging and dynamic gain adjustment, spatial interpolation and windowing are carried out on measurement data, and a sound pressure and frequency measurement algorithm is combined, so that the parameter distribution rule of the sound field in the cleaning tank can be accurately obtained. According to the invention, an on-line detection means can be provided for the ultrasonic cleaning equipment so as to ensure the operation condition of the field cleaning equipment, and reference and basis can be provided for optimizing the structure of the cleaning equipment and the layout of the transducer.

A method for determining a state parameter of a global navigation satellite system receiver and an apparatus, in particular its absolute position, determining being based on—a measured information including a pseudorange, a carrier phase and / or a Doppler frequency measurement, —broadcast information on the satellite orbits and clock offsets, and—high accuracy correction information of a satellite positions, clock offsets, code and / or phase biases, the method comprising: —determining a satellite position estimate and a clock offset estimate based on the broadcast information, —determining a corrected satellite position and a corrected clock offset based on the satellite position estimate and the clock offset estimate by using the high accuracy information, in particular the high accuracy correction information of the satellite position and the clock offset.

The present disclosure relates to the technical field of power system frequency measurement, and discloses a method, device, and electronic device for measuring ultra-high voltage high harmonic frequency, comprising: dynamically selecting the optimal window function type, window length, and sliding step size for the power system operating state based on the time-varying frequency signal characteristics of the power system using an adaptive window information design algorithm based on reinforcement learning; performing a short-time Fourier transform on the time-varying frequency signal based on the selected window function type, window length, and sliding step size, retaining the positive frequency components and deleting the negative frequency components during the short-time Fourier transform process, and converting the time-varying frequency signal from a time domain representation to a two-dimensional time-frequency matrix represented in the time-frequency domain; determining the spectral line position based on the two-dimensional time-frequency matrix, and determining the ultra-high voltage high harmonic frequency based on the main spectral line position, the sampling rate for the time-varying frequency signal, and the selected window length. The above method can improve the accuracy of the measurement results of the ultra-high voltage high harmonic frequency.

The invention discloses a target passive tracking trajectory division method based on azimuth-frequency, and belongs to the technical field of passive sonar underwater multi-target tracking. The objective of the invention is to solve the problem of poor tracking effect of an existing method in a scene that a target has track intersection. According to the method, aiming at a scene that underwater multi-target tracking trajectories are crossed, under the condition of passive tracking of a single observation platform, a frequency measurement value is introduced into a target state to obtain an azimuth-frequency augmented state vector, and azimuth-frequency joint information can improve the discrimination degree of posterior probability solution of a target corresponding to the measurement value, so that the target tracking precision is improved. Therefore, the accuracy of batch division of the targets under the condition of track intersection is improved. And an RB particle filter, a multi-hypothesis tracking technology and a Kalman smoothing filtering technology are combined, so that a good target tracking effect is realized, and the correctness of a tracking result is ensured. The method can be applied to the technical field of underwater multi-target tracking.

The present invention discloses a digital channelized radio frequency storage system. The digital channelized frequency storage module of the radio frequency storage system can perform frequency domain separation on the input signal before storing it, which not only avoids the problem of traditional methods storing superimposed signals and interfering with the output signal, but also effectively avoids the problem of traditional frequency guidance methods that frequency measurement is easily interfered with when multiple signals arrive at the same time. The introduction of the digital channelized frequency storage module can support the acquisition and storage of multiple simultaneously arriving signals, thereby improving the frequency measurement accuracy, achieving the technical effect of precise frequency guidance, and can be used to counter coherent radar. At the same time, the high-speed, multi-bit A / D converter provided by the present invention, after the operating frequency enters the microwave frequency band, can directly acquire and reconstruct the signal in the intermediate frequency or radio frequency band, and maintain the subtle information characteristics such as the phase of the original signal, thereby ensuring that the output signal has good coherence, and can achieve high radio frequency storage accuracy and long signal storage time.

The invention discloses a high-precision frequency measurement system based on a Beidou satellite. The high-precision frequency measurement system comprises a basic signal generation module, a Beidou signal receiving module, a signal processing module, a clock module, a counter module, a display module and an interface module, the interface module is electrically connected with external equipment, the basic signal generation module generates a reference frequency signal, and the Beidou signal receiving module receives a real-time Beidou satellite signal; the signal processing module carries out correction processing on Beidou satellite signals, and the display module displays measurement results. Compared with the prior art, the high-precision frequency measurement system and measurement method based on the Beidou satellite have the advantages of being convenient to operate and use and high in measurement precision.

The invention discloses a broadband harmonic voltage measuring system and method based on an improved CVT, and the system comprises a first current sensor which is used for measuring the first current of a high-voltage capacitor of the CVT; the broadband harmonic wave acquisition device is used for sampling the first current to obtain first current sampling data; and the broadband harmonic analysis device is used for determining an amplitude frequency spectrum of the first current based on the first current sampling data and determining each frequency component of the system voltage based on the amplitude frequency spectrum of the first current. On the basis of a large number of CVTs used in a power system, the broadband harmonic voltage measurement function within the range of hundreds of kHz is achieved by improving the CVT, the original power frequency measurement function of the CVT is not changed, the operation reliability of the CVT is not reduced, and effective broadband, high-precision and low-cost harmonic voltage measurement can be achieved.

The invention discloses a power grid harmonic wave and inter-harmonic wave detection method and device based on distributed multi-frequency measurement data, equipment and a medium. A sine wave method comprises the following steps: detecting harmonic wave and inter-harmonic wave components existing at each sine wave measurement point based on a random matrix theory; determining the frequency and amplitude of each harmonic wave and inter-harmonic wave of each sine wave measurement point by using a rotation invariant technology; clustering the frequency of each harmonic wave and inter-harmonic wave on each measurement point by using a density-based noise application space clustering method to obtain the target frequency of each frequency cluster; and determining harmonics and inter-harmonics of the power grid according to the target frequency and the amplitude. Each harmonic and inter-harmonic component existing on a measurement point is detected through a random matrix theory and a rotation invariant technology, accurate frequencies and amplitudes of the harmonic and the inter-harmonic are obtained, and more accurate frequencies of the harmonic and the inter-harmonic of a power grid are obtained by fusing data of a plurality of distributed measurement points through a clustering method. Therefore, the detection capability of harmonic waves and inter-harmonic waves of a power grid is improved.