131 results about "Doppler effect" patented technology

The invention discloses a hydropower station water level detection method and system. The method comprises the steps that an original water flow characteristic parameter set is obtained through multiple sets of Doppler effect radar flow measuring devices; performing segmentation extraction to obtain a water flow feature sub-data set; inputting a Transform network coding layer to generate a water flow feature coding vector; outputting a preliminary water level predicted value sequence through a decoding layer; a radar flow measurement model is called for correction to obtain a correction sequence; time sequence integration is carried out to obtain a water level change curve. The system comprises a multi-source Doppler radar signal acquisition unit, a spatial-temporal feature segmentation extraction unit, a Transform coding processing unit, a water level preliminary prediction unit, a radar model correction unit and a time sequence integration output unit. According to the method and system, multi-source parameters are deeply fused, the environmental adaptability is improved, the continuity and reliability of a detection result are enhanced, the water level of the hydropower station can be accurately monitored, and support is provided for scheduling decision and safety prevention and control.

Autonomous ground vehicles that are outfitted with radar sensors and inertial measurement units accurately determine states of the autonomous ground vehicles, e.g., estimates of the vehicles' positions, orientations, or velocities or accelerations along or about one or more axes, based on data captured by the radar sensors and the inertial measurement units. Where objects are detected in radar scans, the objects are determined to be static (or fixed), or dynamic (or moving), and landmarks representing static objects are identified. Constraints on estimates of states may be calculated based on doppler effects, inertial measurement unit effects, or locations of landmarks, and the states may be determined as solutions to optimization problems based on the data and the calculated constraints. Odometry messages representing the determined states may be generated and stored or utilized for any purpose.

The invention relates to the field of network security and the deep learning field, in particular to a satellite internet-oriented Tor website fingerprint identification method, which is implemented by constructing a self-supervised contrast learning framework and is implemented by generating a multi-view sample; extracting a feature matrix of the time sequence granularity; generating a synthesized negative sample based on linear insertion, and constructing a contrast with the positive sample; and track representation is extracted, and joint optimization is carried out in combination with cross entropy loss and mask reconstruction loss. Compared with a traditional website fingerprint identification method, the robustness of the model to satellite inherent noise caused by the Doppler effect can be enhanced. According to the method, multi-scale semantic features are provided for the weak enhancement view and the strong enhancement view, the inter-class distinction degree is improved by synthesizing negative samples, and the misjudgment rate is reduced; the joint loss optimization framework enables the model to give consideration to global statistical characteristics and local burst characteristics, and under the conditions of strong dynamic topology and limited labeling of satellite internet constellations, the accuracy and adaptability of website fingerprint recognition are remarkably improved.

A system for millimeter RADAR object recognition and classification using sub-band frequency interference and resonance effects from primary targets signals and reflected signals from secondary target preferably in the form of Wideband Chaos Generating Material (WCGM) objects, preferably detecting frequency dependent absorbing material, frequency dependent resonance effects from the second and primary target objects, frequency signal resonance effects caused by water molecule dipole effects in different sugar solutions, impedance of material, shape of metamaterial, and interference effects due to combination of signal sources resulting in a wider range of transmitter and scanning frequency band for RADAR based interrogation of target objects. The RADAR system makes opportunistic use of traditionally seen problematic interference signals, as extra signal sources providing extended range and frequency bandwidth for frequency-based interrogation of target object signatures in a frequency-intensity plane, a frequency-polarization plane, and a frequency-phase shift plane for doppler effects.

The invention relates to a radar identification warning method applied to an electric power line protection area, and relates to the technical field of electric power monitoring. According to the method, radar working parameters are configured by using an environment-corrected radar equation and a genetic algorithm considering a radar coverage range, radar detection accuracy and radar energy consumption; the radar detects a target in a power line protection area to obtain radar point cloud data; in the process, multi-frequency fusion ranging is used for measuring the distance of a target, and the Doppler effect is used for resolving the speed of the target; detecting and repairing abnormal values of the radar point cloud data based on an isolated forest algorithm; inputting the preprocessed radar point cloud data into a pre-trained integrated learning classifier for target identification, and obtaining target category information, speed, distance, environment data and facility operation data as risk assessment data; the risk assessment model assesses a target risk according to the risk assessment data to obtain a target risk value and a risk level probability; and performing graded warning according to the target risk value and the risk grade probability.

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 present application relates to the technical field of radar detection, and particularly relates to a particle flow multi-parameter detection method based on MIMO-FMCW radar, a medium and equipment, the particle flow multi-parameter detection method based on MIMO-FMCW radar comprises the following steps: S1, arranging a virtual channel array structure of × in a detection area, and obtaining a digital signal matrix of multiple frames of measurement data corresponding to the detection area by using the virtual channel array structure; S2, obtaining multiple parameters of the particle flow in the detection area based on the digital signal matrix.The present application synchronously obtains data in the time, frequency and spatial domain by using the MIMO-FMCW radar system, realizes the joint measurement of the multiple parameters of the particle flow, can extract the speed information by the Doppler effect of the FMCW signal, can form a virtual channel to extract the angle information, and simultaneously combines the signal amplitude to estimate the concentration, so that comprehensive particle flow movement characterization is realized.

The invention relates to the technical field of acoustic signal processing, and discloses a sound source positioning method and system, and the method comprises the steps: collecting sound through a multi-microphone array, aligning data based on a synchronization mechanism, and obtaining an initial time domain signal; executing transformation and filtering to generate a spectrogram; separating interference based on noise estimation, and extracting independent source frequency domain components; calculating a time difference in combination with a synchronization mechanism, and determining a preliminary orientation; the moving direction is analyzed, the track is smoothed, and continuous track data are obtained; constructing a velocity vector to generate a Doppler compensation coefficient, and executing phase calibration to obtain a calibration signal; and performing inverse transformation on the reconstructed signal, and calculating a generalized cross-correlation peak value to determine a final position. The method can achieve the precise tracking and positioning of a dynamic sound source, effectively eliminates the Doppler effect and environment noise interference, and remarkably improves the positioning precision.

This invention relates to a method for detecting and countering unmanned aerial vehicles (UAVs). It deploys a multi-dimensional sensing network for instantaneous scanning across the entire frequency band, simultaneously acquiring noise characteristics of radio signals, material characteristics in the terahertz band, and Doppler effect characteristics. These are mapped to a virtual twin to reconstruct the physical parameters, communication protocols, and behavioral patterns of the target UAV. A deep comparison is then performed using a camouflage sample library generated by an adversarial generative network to generate a holographic target profile containing three-dimensional motion vectors, energy characteristics, and potential threat intent. Quantum entanglement signals are used to interfere with the target's quantum-encrypted communication link, generating a controllable plasma cloud to selectively attenuate its navigation and image transmission signals. The controllability of the target is assessed, and uncontrollable targets are driven away using coded acoustic waves. Control commands incorporating bio-inspired obstacle avoidance algorithms are sent in stages to guide the UAV to an intelligent recovery pod. This invention achieves accurate detection, intelligent identification, secure countermeasures, and reliable takeover of UAVs, enhancing airspace security capabilities.

The invention relates to the technical field of radar detection, in particular to a particle flow multi-parameter detection method based on an MIMO-FMCW radar, a medium and equipment, and the method comprises the steps: S1, arranging an x virtual channel array structure in a detection region, adopting a virtual channel array structure to obtain a digital signal matrix of multi-frame measurement data corresponding to the detection area; and S2, obtaining multiple parameters of the particle flow in the detection area based on the digital signal matrix. The MIMO-FMCW radar system synchronously obtains data in time, frequency and space domains, multi-parameter combined measurement of particle flow is achieved, speed information can be extracted through the Doppler effect of FMCW signals, a virtual channel can be formed to extract angle information, meanwhile, the concentration is estimated in combination with the signal amplitude, and comprehensive particle flow characterization is achieved.

A video device (100) is provided with: a plurality of transmitters (101) for transmitting fluctuations to a measurement region; a plurality of receivers (102) that receive fluctuating scattered waves from the measurement region; and an information processing circuit (103) that uses the measurement data of the scattered waves to image an object in the measurement region, and that derives a scattered field function using the measurement data and the velocity vector of the object. Deriving a video function that is determined using the amount that is output from the scattered field function by inputting the position of the object to be video into the scattered field function, and video the object in the measurement region using the video function; the information processing circuit (103) changes the number of scattered waves reflected by the scattered field function due to the Doppler effect corresponding to the velocity vector.

This invention belongs to the field of radar technology and discloses a method for simulating and generating radar target CPI echoes based on precise electromagnetic calculations. This invention proposes to obtain the omnidirectional broadband electromagnetic scattering characteristics of a target using commercially available precise electromagnetic calculation software. Given the target's heading, speed, and radar parameters, it introduces the effects of antenna pattern modulation, target undulation model, Doppler effect, and signal processing response to simulate and generate a generalized radar target coherent or non-coherent CPI pulse group echo applicable to any radar parameters and target type. This method is applicable to different targets and radar types and significantly improves the reliability of target echo simulations.

The application relates to the technical field of signal processing, and discloses a code Doppler effect elimination method in a signal combination process. Before signal combination, a time domain cyclic shift is performed on the autocorrelation function before combination, or a frequency domain rotation factor compensation is performed on the FFT transformation of the autocorrelation function, and then IFFT transformation is performed to the time domain. The application solves the problem that the prior art lacks a technical scheme capable of efficiently and accurately eliminating the code Doppler effect.

The application discloses a kind of monitoring devices of pressure fluctuation frequency and amplitude in cavitation collapse process, including water tank, cavitation generator, magnetic fluid, magnetic field device, laser generator, optical splitter, laser probe and receiver;Optical splitter is emitted by single beam laser of laser generator and is divided into two beams, one is emitted as laser, frequency is f ;Another is as reference laser, frequency is f + f r ;Laser probe exports and irradiates on the tip of magnetic fluid by emitting laser, and reflection is formed to form reflected laser, and its frequency is f + f D ;Receiver, accept reflected laser, and it has reference laser inside by optical splitter, and its frequency is f + f r The application can master the whole dynamic data of quantized cavitation collapse by monitoring the frequency and amplitude of whole process pressure fluctuation caused by cavitation collapse in liquid environment through magnetic fluid magneto-rheological effect, tip surface effect and Doppler effect, which provides important technical means for single-cavity theory development and hydraulic machinery cavitation flow research.

This invention provides a method for identifying the sound source of a ducted fan. First, a series of microphone arrays are set along the axial direction of the duct to monitor the sound pressure signal. Second, the measured sound pressure signal is transformed to the position of a virtual microphone array that rotates synchronously with the sound source. Next, the transformed sound pressure signal is processed using beamforming, and then focused to obtain the sound source signal. Finally, the sound source distribution is identified based on the sound source signal. This method for identifying the sound source of a ducted fan, by transforming the sound pressure signal measured by a fixed microphone array into the position of a virtual microphone array that rotates synchronously with the sound source, cancels the Doppler effect caused by the rotation of the sound source, thereby reducing the complexity of solving the delay time problem during sound source focusing and facilitating the localization and identification of rotating sound sources within ducts.

The utility model provides a GPS velocimeter for a model airplane unmanned aerial vehicle, the GPS velocimeter is clamped in a remote controller, one end of the velocimeter is externally connected with a display, the other end of the velocimeter is externally connected with a power supply end, the GPS velocimeter comprises an actuation system, a chip in the actuation system is provided with a common velocity measurement unit and an accurate velocity measurement unit, the common velocity measurement unit and the accurate velocity measurement unit are both electrically connected with the chip, a receiver is arranged in parallel with the chip and electrically connected with the chip, and the receiver is electrically connected with the chip. The common speed measurement unit outputs standard NMEA data and is suitable for daily speed measurement in a low-power-consumption state; the precise speed measurement unit outputs ground speed based on the Doppler effect, high-precision scene requirements such as racing or complex surveying and mapping are met, the receiver ensures that GPS signals are rapidly received and processed, efficient operation of the system is achieved, the defect of a single-precision mode is overcome through the design, precision and power consumption are considered, and various task requirements are met.

The invention relates to the field of wireless communication, in particular to a method and device for sending or decoding sound wave signals. In sound wave communication, relative movement between a sending end and a receiving end can generate a strong Doppler effect, and serious interference is caused to the sound wave communication. In the application, the transmitting end transmits the probe signal when transmitting the communication signal, the transmitting frequency of the probe signal is information known by the receiving end, and the receiving end can estimate the frequency shift based on the transmitting frequency and the receiving frequency of the probe signal. The Doppler effect has almost the same influence on the communication signal and the probe signal, and the receiving frequency of the communication signal can be corrected by using the frequency shift, so that the interference of the Doppler effect on sound wave communication can be reduced.

The laser blood flow detector based on the Doppler effect comprises a shell, an operation panel is arranged on the shell, a detection port and an operation button are arranged on the operation panel, a display screen is arranged above the shell, and a control mechanism is arranged in the shell. The control mechanism comprises a laser, a light separator and a photoelectric receiver which are arranged in the detection probe and a signal processor arranged in the shell, the output end of the laser is connected with the input end of the light separator, the output end of the light separator is connected with the input end of the photoelectric receiver, and the output end of the photoelectric receiver is connected with the input end of the signal processor; the output end of the signal processor is connected with the input end of the display screen. The system is low in cost, high in precision, stable in performance and simple to operate, improves the blood detection efficiency, and provides an important basis for cardiovascular system function evaluation and disease diagnosis by providing quantitative data of blood flow.

The invention provides a communication method and device and a storage medium. According to the invention, when the Doppler effect of the sensing target is determined through the sensing reference signal, the sensing reference signal sent to the sensing target is configured in a way that the repetition period of the borne sequence in time is greater than the length of one wireless frame, so that the sequences of the sensing reference signals on two adjacent wireless frames are not repeated; therefore, the estimation performance of the Doppler effect of the sensing target can be improved, and the accuracy of the determined position of the sensing target and other parameters can be improved.

The invention relates to a Doppler effect-based wind speed and visibility collaborative measurement method, which comprises the following steps of: firstly, selecting a known visibility region and a corresponding power value; then, infrared pulse signals with set power and different wavelengths are transmitted to the known area, two sensors at a receiving end are adopted to receive scattering echo signals, an equipower curve with double-peak calibration power is formed through fitting, and then equipower curves with different powers are formed; and finally, according to actual measurement, scattering echo signals are received according to a sensor, the power of the two scattering echo signals is substituted into an equipower curve of different power, the target power and the corresponding wavelength are obtained, and the visibility and the wind speed of the target area are calculated based on the Doppler effect. According to the invention, synchronous high-precision measurement of wind speed and visibility is realized. The double-peak curve constructed by the invention can realize simultaneous measurement of wavelength and power, so that cooperative acquisition of wind speed and visibility is realized, and the defect that wind speed measurement cannot be realized by adopting a single sensor in an existing visibility meter is overcome.

This invention relates to a method and system for locating coaxial counter-rotating sound sources in rotorcraft, belonging to the technical field of sound source identification methods. It includes: processing the sound pressure signal of the moving sound source using continuous wavelet transform to obtain time-frequency domain variation results; performing Doppler effect correction based on experimental conditions; estimating the spatial location and relative intensity of the noise source using a cross-spectral matrix and weight vector; and performing phase-locked analysis of the rotor noise source intensity using a phase-locked averaging method. This invention differs from traditional time-domain delay superposition algorithms and frequency-domain cross-correlation spectrum methods. It can image unsteady sound sources using time-frequency domain characteristics, solving the acoustic imaging problem of counter-rotating propeller noise and possessing potential applications in the rotorcraft industry.

A laser vibration measuring instrument series reciprocating optical frequency modulation calibration method and device belong to the field of photoelectric measurement. The calibration device is mainly composed of a calibrated laser vibration measuring instrument, a first acousto-optic modulator, a second acousto-optic modulator, a lens, a first sinusoidal signal source, a second sinusoidal signal source, an FM signal source and a plane mirror. For the laser signal emitted by the laser vibration measuring instrument, the reversibility of the optical path is used, the "I" type optical path structure is used, the output frequency translation and modulation control of the laser vibration measuring instrument are realized by using the twice optical frequency modulation mode of the same group of optical devices combined with twice optical frequency translation, the laser Doppler effect caused by different vibration waveform values is simulated, the modulated laser is completely returned to the calibrated laser vibration measuring instrument along the original path, the change waveform of the frequency value is replaced by the change waveform of the vibration speed value, and the calibration of the laser vibration measuring instrument is realized. The present application has the advantages of portability, wide frequency range, wide amplitude range calibration, high precision and good stability.

The invention discloses a rotating sound source recognition and positioning method based on a deep convolutional attention neural network, and belongs to the field of rotating sound source recognition, and the method comprises the steps: firstly carrying out the motion compensation and modal expansion of a sound pressure cross-spectrum matrix through a modal decomposition rotating beam forming algorithm, and generating a sound source distribution diagram in a rotating scene; then the sound source distribution map is input into a deep convolution attention neural network model, the model adopts an encoder-decoder structure, a channel and a space attention mechanism are fused, key sound source features are dynamically focused, noise interference is suppressed, and high-precision reconstruction of the sound source distribution map is achieved; and finally, carrying out local maximum value detection on a prediction map output by the network, and extracting a sound source space position. According to the method, the Doppler effect and phase distortion problems in rotating sound source positioning are effectively overcome, and the positioning precision, the anti-noise performance and the calculation efficiency in a complex rotating field are remarkably improved.

The invention discloses a rotating sound source separation method based on fast Bayesian inference, and the method comprises the steps: dividing a plane where a sound source is located into uniform or non-uniform equivalent source grid points, enabling each grid point to represent an equivalent sound source so as to describe the sound field energy contribution of a rotating sound source and a static sound source, and dividing scanning grid points which coincide with the equivalent source grid points; for mixed sound signals collected by a microphone array, scanning grid point output is calculated by adopting a traditional beam forming algorithm and a modal composition beam forming method considering the Doppler effect of a rotating sound source, key features of two kinds of beam forming output are extracted based on a convolution kernel, and preliminary acceleration is achieved by calculating an approximate transfer matrix through convolution.

The present application relates to the field of wireless communications, and in particular to a method and apparatus for sending or decoding an acoustic wave signal. In acoustic wave communication, the relative movement of a sending end and a receiving end may generate a strong Doppler effect, which causes severe interference to the acoustic wave communication. In the present application, a sending end sends a probe signal when sending a communication signal, and the sending frequency of the probe signal is information that is known to a receiving end. The receiving end can estimate a frequency shift on the basis of the sending frequency and a receiving frequency of the probe signal. Since the communication signal and the probe signal are sent at the same time or at a relatively short interval, and the impacts of the Doppler effect on the communication signal and the probe signal are almost the same, the frequency shift can be used to correct a receiving frequency of the communication signal, so as to reduce the interference with the acoustic wave communication caused by the Doppler effect.

The invention provides a rotating sound source beam forming method based on improved wavelet transform, which comprises the following steps of: firstly, executing Morse wavelet transform on data received by each microphone, and converting a time domain signal into a time-frequency domain signal; then, parameters related to the Doppler effect are calculated, and a Doppler effect correction Green function is introduced; then, calculating a weight vector and a cross-spectrum matrix formed by an array beam; and finally, grid division is performed on a plane where a target signal is located, and beam forming is performed on each grid point by using the time-frequency array signal model on each wavelet domain so that sound imaging of a target sound source can be realized. Compared with a traditional beam forming method based on Fourier transform, the beam forming method based on improved wavelet transform has the advantage that the real-time imaging quality and background noise suppression are remarkably improved.

The application discloses a detonation test method and device based on laser technology in the technical field of detonation experiment test, S1, detonation ignition, makes the flyer pass through the first observation point, the second observation point and the third observation point in turn; S2, laser Doppler effect monitoring, wavelength change data when the laser beam irradiates the flyer is acquired through the end laser interferometer; then the first observation point, the second observation point and the third observation point respectively emit positioning laser beams to carry out again Doppler effect monitoring on the passing flyer, positioning wavelength change data is obtained; S3, the time when the flyer passes through each observation point is determined, the corresponding flying time and passing time of the flyer under the first observation point, the second observation point and the third observation point are obtained based on the wavelength change data and the positioning wavelength change data; then the passing time is corrected based on the flying time; so as to eliminate the cumulative error, make the obtained experimental data more accurate, and facilitate the accurate prediction of the speed of the flyer.

The invention provides a Doppler effect elimination and fusion positioning method for a high-speed train, and the method comprises the steps: deducing a mathematical expression of a distance measurement error caused by a Doppler effect based on a bidirectional time of flight (ToF) method; secondly, using UWB / IMU time sequence prior to eliminate distance measurement error deviation, and analyzing residual error variance; and finally, constructing a self-adaptive UWB / IMU fusion positioning framework, deducing a UWB measurement equation random item closed expression, and realizing Doppler effect elimination and fusion model parameter self-adaptive adjustment. According to the method, the precision of UWB / IMU fusion positioning is remarkably improved, and the influence of the Doppler effect on the bidirectional ToF ranging and fusion positioning model is overcome.

The present invention relates to a smart device for recognizing a hand motion of a user by recording, by a microphone, a reflected wave caused by the hand motion of the user when an ultrasonic wave is emitted from a speaker and analyzing the reflected wave, wherein the smart device according to an embodiment may comprise: a speaker unit for emitting an ultrasonic signal; a microphone unit for receiving a reflected wave returning after the emitted ultrasonic signal is reflected by a body part of the user; and a motion recognition unit for recognizing a motion of the body part of the user by analyzing the received reflected wave on the basis of the Doppler effect.

A kind of tip timing method and device based on laser Doppler effect, for realizing fiber tip timing;The method comprises the following steps: step S1, laser is sent out, through fiber beam splitter and laser is divided into first light beam and second light beam;Step S2, first light beam is irradiated to blade tip by temperature-resistant fiber probe, and the laser reflected by blade tip is received, signal light participating in interference is formed, and is sent to fiber combiner;Step S3, second light beam is sent to fiber combiner, and reference light participating in interference is formed;Step S4, signal light and reference light interfere to form interference light field, and the electrical signal of interference light field is acquired;Step S5, blade tip time ti is obtained according to electrical signal;And a kind of tip timing device based on laser Doppler effect, the blade tip time of the blade tip of the engine blade in the engine casing of engine is measured.The present application has the advantages of accurate measurement and high engineering applicability.