1198 results about "Doppler us" patented technology

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

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

The invention discloses a communication-detection integrated sonar signal design method and device based on multi-pulse composite modulation, and the method comprises the steps: dividing a total frame period into a detection sub-frame and a communication sub-frame, enabling the detection sub-frame to achieve the high-resolution distance measurement through employing a bidirectional linear frequency modulation (BILFM) signal, a communication sub-frame adopts a multi-frequency multi-phase composite modulation (MTPM) signal to realize high-bit-rate data transmission; after band filtering, orthogonal demodulation, low-pass filtering and down-sampling preprocessing are carried out on detection sub-frame echoes, distance and speed information is extracted by adopting fast-time low-sampling two-dimensional fast Fourier transform (2D-FFT), unambiguous Doppler frequency is recovered by utilizing the Chinese remainder theorem (CRT), and accurate speed measurement of long-distance and high-speed targets is realized; a communication subframe receiving signal is subjected to IQ demodulation after down-conversion, Costas loop carrier synchronization and matched filtering, and multi-frequency multi-phase coded data are extracted. According to the method, the time-frequency collaborative design of detection and communication is realized, the distance resolution and the speed measurement range are considered, and the signal bandwidth utilization rate and the underwater information transmission reliability are remarkably improved while the system complexity is kept low. The device comprises a processor and a memory, and an executable program for implementing the method is stored in the memory. The technology can be widely applied to the fields of unmanned underwater vehicles, ocean monitoring, underwater sensing networks and the like.

The invention relates to the technical field of intelligent early warning, and discloses a multi-mode intracranial pressure intelligent early warning method and system.The method comprises the steps that an intracranial pressure waveform signal, an electroencephalogram signal and a transcranial Doppler blood flow velocity signal are synchronously collected, and a multi-mode physiological data set is obtained; extracting time domain features, frequency domain features and nonlinear features of the preprocessed multi-modal physiological data set to obtain a standardized feature parameter set; distributing dynamic weights for features in the standardized feature parameter set according to feature modal types of the standardized feature parameter set to obtain a fusion feature vector; performing intracranial pressure prediction on the patient according to the fusion feature vector after nonlinear transformation to obtain an intracranial pressure change sequence; according to the deviation condition of the intracranial pressure change sequence and a clinical preset safety threshold value, an intracranial pressure early warning signal is output; the accuracy of intracranial pressure early warning can be improved.

The invention belongs to the technical field of wind driven generator state monitoring, and discloses a millimeter wave and vision fused fan blade clearance monitoring system, which comprises a central processing unit, a wind driven generator, a millimeter wave radar sensor, a millimeter wave radar sensor and a millimeter wave radar sensor, and is characterized in that the central processing unit establishes a reference time difference according to blade transit timestamps acquired by the vision and millimeter wave radar sensor; during operation, a blade instantaneous angular velocity is determined by using visual data so as to correct a real-time timestamp, a comparison result of a dynamic time difference and a reference is calculated and is used as an initial diagnosis signal, and risk levels are discriminated by analyzing Doppler spectrum width characteristics of radar echoes in case of abnormality. According to the method, the fan master control system has the capability of distinguishing and recognizing the individual state abnormity of the single blade for the first time, the monitoring granularity is lowered to the component level from the complete machine level, and the improvement from passive response type control to predictive adaptability control is achieved.

The invention discloses an AGV safety control method for intelligent warehousing, and relates to the technical field of intelligent warehousing, and the method comprises the following steps: constructing a global three-dimensional load distribution diagram of an automatic guided vehicle in real time through the fusion of a laser radar and an inertial measurement unit, and outputting a mass distribution matrix; based on the mass distribution matrix, millimeter wave Doppler tomography is superposed, the barycentric coordinates are dynamically corrected, and a corrected mass distribution matrix is obtained; and inputting the corrected mass distribution matrix into a braking dynamic prediction engine, and generating a prediction curve of an adaptive braking distance and braking response time in combination with online inversion estimation of a ground friction coefficient. Through the digital twin simulation and micro-pulse pre-braking strategy, the risk of inertial collision and cargo overturning is effectively reduced, a storage scheduling system is controlled in parallel, path reconstruction and driving priority dynamic adjustment are achieved, and global safety and efficient scheduling of intelligent storage are guaranteed.

The invention relates to the technical field of laser radar wind field inversion, in particular to a coherent Doppler anemometry laser radar-based three-dimensional wind field inversion method, which comprises the following steps of: acquiring original power spectrum data of an anemometry laser radar to be inversed in each direction, and sequentially performing interpolation processing on the original power spectrum data in each direction to obtain an inversion result; obtaining power spectrum data after interpolation in each direction; calculating to obtain a cumulative power spectrum function; and optimizing the obtained vector three-dimensional wind field by using the cumulative power spectrum function so as to calculate the maximum function value of the cumulative power spectrum function, and the three-dimensional wind field corresponding to the maximum function value is the optimal three-dimensional wind field. According to the method, all the power spectrum data after azimuth interpolation are directly processed as a whole, random noise is averaged by using an accumulation process, a real signal is highlighted, and stable and accurate three-dimensional wind field inversion can be realized even when the signal-to-noise ratio is extremely low.

The invention discloses a large-scale underwater vehicle three-dimensional dynamic obstacle avoidance method based on multiple single-beam sonar arrays, and the method comprises the steps: S1, collecting three-dimensional space detection data according to the arrangement of a space array composed of a center sonar and four peripheral sonars, and generating three-dimensional environment perception information; s2, based on the three-dimensional environment perception information, fusing data of an inertial navigation system, a Doppler velocimeter and a depth sensor, and generating real-time attitude and obstacle distribution information of the underwater vehicle; s3, on the basis of the real-time attitude of the underwater vehicle and the obstacle distribution information, risk level assessment and obstacle avoidance path planning are executed, and an obstacle avoidance control instruction is generated; and S4, based on the obstacle avoidance control instruction, controlling a power system of the underwater vehicle to adjust the course, the pitch angle and the speed so as to realize three-dimensional dynamic obstacle avoidance. The problem that a traditional single-beam sonar is insufficient in stereoscopic perception capability is solved, and the defect that the traditional single-beam sonar cannot effectively detect obstacles in the pitch angle direction (such as a submarine abrupt slope and a suspended rock frame) is overcome.

The invention discloses a Doppler frequency offset estimation method and electronic equipment, and relates to the technical field of communication, and the method comprises the step that the electronic equipment communicates with a low-orbit satellite in a discontinuous reception (DRX) mode. Wherein in a discontinuous reception (DRX) mode, the electronic equipment enters a wake-up period when the wake-up moment arrives, the electronic equipment communicates with a low-orbit satellite in the wake-up period, the electronic equipment enters a sleep period when the sleep moment arrives, and the electronic equipment stops communicating with the low-orbit satellite in the sleep period. When the wake-up moment arrives, the electronic device obtains at least one historical Doppler frequency offset value; and the electronic equipment determines a Doppler frequency offset value corresponding to the wake-up moment based on the historical Doppler frequency offset value. In the scheme, the Doppler frequency offset value at the wake-up moment is estimated through the historical Doppler frequency offset value, and the electronic equipment can calculate the Doppler frequency offset value at the current wake-up moment, so that frequency offset compensation can be carried out in time at the current wake-up moment, and the performance of frequency offset compensation is optimized.

The invention discloses a dynamic calibration device and method for a visual vibration measurement system, the device comprises a dynamic standard vibration source, a calibration target, a laser Doppler interferometer, a data processing unit and a control unit, the dynamic standard vibration source outputs steady state, transient state and random vibration signals, the calibration target is fixed at the vibration output end of the dynamic standard vibration source, and the laser Doppler interferometer is fixed at the vibration output end of the dynamic standard vibration source. An acquisition target is provided for a calibration process; the calibrated visual vibration measurement system collects a dynamic image to obtain a vibration measurement parameter, and the laser Doppler interferometer synchronously obtains a standard vibration dynamic parameter; the data processing unit receives the dynamic vibration measurement parameters and the dynamic standard vibration parameters, and quantifies dynamic amplitude deviation, frequency tracking delay and phase difference; and the control unit generates calibration parameters of the calibrated visual vibration measurement system according to the type of the dynamic error under the condition that the dynamic error exceeds an error threshold value. According to the invention, quantitative evaluation and automatic calibration of the dynamic error can be realized, and the calibration precision and efficiency are improved.

The invention particularly discloses a fractured rock mass grouting three-dimensional visualization test device and method, and relates to the technical field of rock mass engineering. The device comprises a test box body, a liquid inlet and outlet system, a monitoring system and a dynamic water environment simulation assembly, the test box body is made of a transparent acrylic material and is composed of an upper cover plate, a lower cover plate, a front cover plate, a rear cover plate, a baffle and two side cover plates, and a core experiment module is arranged in the test box body; the liquid inlet and outlet system is sequentially connected with the liquid holding device, the peristaltic pump, the valve, the Doppler flow velocity sensor and the test box body through rubber pipes; the monitoring system integrates an image collection unit and a data monitoring unit, an industrial-grade 3D camera and a binocular camera achieve visualization of the displacement process, and a fiber bragg grating pressure sensor synchronously collects fracture pressure data and transmits the fracture pressure data to a computer through a multifunctional data collection module. The device can be used for observing the displacement process of the slurry in the three-dimensional fracture in real time, synchronously monitoring key parameters, adapting to complex test working conditions and providing reliable support for grouting law research.

The invention belongs to the technical field of brain function monitoring, and discloses a three-in-one non-invasive brain function monitoring system and method, a medium, equipment and application, and the monitoring method comprises the following steps: monitoring brain oxygen saturation of a critical patient; carrying out transcranial Doppler ultrasonic measurement on intracranial blood vessel blood flow velocity and ultrasonic measurement on the inner diameter of the optic nerve sheath; monitoring a quantitative electroencephalogram of the patient; various brain function monitoring series indexes and continuous changes of the indexes along with disease evolution are obtained, the pathogenic mechanism and pathogenesis of the indexes are found in time, and primary diseases and related complications of the primary diseases are treated. According to the invention, the brain oxygen saturation can avoid too low brain oxygen or low brain oxygen for a long time and too high brain oxygen due to oxygen utilization disorder; cerebral blood flow can be monitored through a transcranial Doppler (TCD) technology to find an optimal craniocerebral perfusion pressure (CPP), and a cerebral blood flow self-adjusting function is enabled to be in an optimal state; the electroencephalogram can avoid early warning of over-sedation or abnormal discharge and the like. Through organic combination of the three, noninvasive, real-time and dynamic monitoring of critical patients is realized.

The invention provides a monitoring method and system for the conveying state of grain capable of being washed based on multi-mode sensing. Multi-axis laser speed measurement probes with dust covers are arranged on the two sides of the conveying belt, so that interference of dust to a light path is eliminated. Laser Doppler frequency shift signals of surface particles and echo intensity data of deep particles are synchronously collected, and a hierarchical control volume model is established; and utilizing the echo intensity to compensate the scattering signal, and generating a flow velocity distribution profile map through self-correlation processing. A particle motion vector field is further constructed by adopting an optical flow method, and a collision energy value is calculated through vector field energy distribution. When the energy value exceeds a preset threshold value, a positioning early warning signal is generated, and real-time monitoring and accurate positioning of particle collision abnormity are achieved. According to the technical scheme, full-dimension monitoring of the particle motion state in the grain conveying process can be achieved in the high-dust environment, collision abnormity is effectively recognized, the fault area is accurately positioned, and the grain conveying quality is guaranteed.

The invention provides a crane commander gesture recognition method based on a multi-branch G-LSA millimeter wave radar, and the method comprises the steps: transmitting a frequency modulation signal through an FMCW millimeter wave radar, and receiving an echo signal reflected by a gesture; performing frequency mixing and processing on the emission signal and the echo signal to obtain a beat frequency signal, and acquiring gesture signal data of a commander in a real application environment through ADC sampling; performing signal preprocessing on the sample to obtain micro-Doppler features of the sample, establishing a corresponding point cloud data set D, and performing unified processing on the micro-Doppler features of the sample to obtain a three-dimensional mixed feature tensor; constructing a gesture recognition model based on multi-branch G-LSA, training the model, and optimizing the weight of the model to obtain a gesture recognition model; aDC data of gesture actions of a crane commander are collected, and a three-dimensional mixed feature tensor of the ADC data is obtained and input into a multi-branch G-LSA gesture recognition model; an identification result is sent to a crane cab; according to the method, a safer and more reliable gesture interaction scheme is provided for high-precision and high-risk scene optimization such as crane command.

The invention introduces a Doppler radio direction finding system, which relates to the technical field of radio navigation and comprises an antenna array unit, a radio frequency switch matrix, a logic controller, a single-channel receiver and a signal processing unit. The logic controller drives the radio frequency switch matrix to alternately execute clockwise and anticlockwise antenna scanning actions in a single measurement period, and the signal processing unit respectively extracts phase slopes corresponding to forward and reverse scanning, generates an environment error component according to the sum of the two phase slopes and identifies a specific antenna oscillator at a standing wave node. The logic controller responds to the feedback instruction and physically skips the conduction operation on the specific antenna oscillator in the subsequent time sequence, the physical symmetry of positive and negative scanning and an environment feedback mechanism are utilized, environment standing wave interference is actively avoided on the premise that radio frequency channels are not increased, and qualitative change improvement of anti-multipath direction finding precision under a single-channel system is achieved.

The invention relates to the technical field of radar information, in particular to a ground clutter suppression method for a ground reconnaissance radar, which comprises the following steps of: firstly, establishing a clutter profile map by using echo data, judging information inside and outside a clutter according to the clutter profile map, and selecting different signal processing flows, namely, adopting a detection channel 1 outside the clutter, adopting a detection channel 2 and a detection channel 3 inside the clutter and adopting a detection channel 2 and a detection channel 3 outside the clutter; after the detection channel 1 passes through the MTD filter, clutter suppression processing is not carried out, and a detection result is output; the detection channel 2 is a coherent processing channel, firstly performs mean filtering processing, then performs coherent processing, performs clutter suppression processing through phasor mean filtering, and outputs a detection result; and the detection channel 3 is a zero Doppler processing channel and is used for detecting a low-speed target in a clutter area, compared with the prior art, the method can reduce Doppler sidelobes as much as possible on the premise of ensuring that the ground clutter height is suppressed, and has the minimum main lobe width and the minimum signal-to-noise ratio loss.

The invention relates to a high-speed target speed estimation method based on minimum entropy coarse and fine combination fast search. The method comprises the following steps: carrying out bandwidth synthesis on a baseband signal of a linear frequency modulation stepping echo signal; performing coarse velocity search on each sub-pulse, and performing phase compensation and coherent accumulation on each sub-pulse at each candidate coarse velocity; the waveform entropy of each candidate coarse velocity is calculated, and the candidate coarse velocity corresponding to the minimum entropy value in the waveform entropies is used as the optimal coarse velocity; compensating the intra-pulse Doppler distance coupling time shift of the baseband signal; performing distance pulse compression on the signal after coarse speed compensation; and performing bandwidth synthesis on the sub-pulse signals after pulse compression, performing fine grid search, performing phase compensation and coherent accumulation on each sub-pulse by using a fine phase compensation function for each searched fine velocity, and finally performing search according to a waveform entropy minimization principle to obtain an optimal fine velocity. According to the method, high-precision speed measurement and high-resolution range profile synthesis are synchronously completed in a single-frame signal.

The invention discloses a flow field adaptive calculation method and system based on an acoustic Doppler flow meter. Comprising the following steps: acquiring original frequency spectrum data and synchronous attitude, position and water level information of a Doppler current meter; performing preprocessing and quality marking on the original data; multi-dimensional features are extracted, and a current dominant flow field type is identified through a pre-trained flow field classification model; adaptively selecting a flow velocity profile reconstruction algorithm according to the flow field type, and dynamically adjusting key algorithm parameters according to flow field stability or turbulence intensity parameters in the reconstruction process; a calculation grid is dynamically generated based on a flow velocity field of a reconstruction strategy to perform flow integral calculation, and data, a model and an integral error are comprehensively evaluated to quantify uncertainty of an output flow result; and finally performing flow field abnormity diagnosis, short-term flow trend prediction and equipment health state early warning. According to the method, the problem of insufficient precision of a traditional fixed algorithm in a complex flow field is solved, and the reliability and the intelligent level of flow monitoring are remarkably improved.

The invention relates to an open boundary circulating flow and reconfigurable terrain collaborative maritime work scouring intelligent test system and test method, a maritime work structure test model is installed at the center position of a main body structure inner cavity test section, and a set area with the maritime work structure test model as the center is used as a main test section; the open-boundary circulating flow generation system realizes back supplement and closed-loop operation of circulating water channels of the left bank and the right bank; a multi-beam three-dimensional terrain scanner is installed on the side portion of the large-span electric measuring bridge system, and sand bed terrain and scour pit three-dimensional shape data are obtained; a three-dimensional acoustic Doppler current meter and a capacitive wave height meter are installed on the track type instrument bridge measuring system, and multi-dimensional dynamic monitoring is conducted on the sand bed terrain and the scouring pit; the multidirectional irregular wave generation system is used for simulating regular waves and irregular waves in an offshore environment. According to the invention, the aspects of structure scale, terrain coupling and measurement and control feedback intelligence are comprehensively upgraded, and a more real and reliable test basis with strong engineering adaptability is provided for research on scouring stability of major ocean engineering.

The invention relates to the technical field of communication, in particular to a high-precision measurement method for radial velocity of a shallow sea underwater acoustic target based on ray sound field reconstruction, which comprises the following steps of: establishing a three-path propagation model comprising direct arrival, water surface reflection and seabed reflection, and constructing a joint representation equation comprising channel impulse response and target motion parameters by the path propagation model; according to the method, a space-time joint representation model of multipath sound rays is constructed, and the limitation of a traditional single-path model is broken through by quantifying the coupling relation between propagation time delay and Doppler frequency shift of different paths; the development provides a new technical means for underwater target tracking and positioning, underwater acoustic communication Doppler compensation and marine environment dynamic monitoring, and especially has an important application prospect in the fields of underwater unmanned cluster collaboration and the like.

The invention relates to the technical field of data processing, and discloses a hydropower station fish gathering system inlet flow field adaptability optimization method and system. The method comprises the following steps: grading target fishes according to swimming speed and body length, setting a flow velocity adaptation threshold value, monitoring a flow field through an acoustic Doppler current meter, fusing data by using a Kalman filtering algorithm, calculating a fish rheotaxis index, and carrying out matching analysis to evaluate the adaptability of the flow field, according to the evaluation result, the flow guide pier and the microbubble curtain are controlled to conduct multi-stage linkage regulation and control, and a fuzzy PID control algorithm is adopted to achieve self-adaptive flow field control with the fish hydrotaxis index as a feedback signal. The problem that flow field optimization lacks fish behavior response feedback and multi-device coordination control in the prior art is solved, and the biological adaptability and the regulation and control precision of the inlet flow field of the fish gathering system are improved.

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.

Systems and methods are provided for reducing the reliance on operator skill during vascular ultrasound procedures. The placement of an ultrasound probe to assess perfusion associated with a wound may be facilitated by receiving input suitable for identifying an anatomical region associated with the wound and providing an indication of a suitable initial probe position, and optionally, probe orientation, for acoustically interrogating a target arterial vessel known to provide perfusion to the anatomical region associated with the wound. Regions exhibiting arterial flow may be detected as the probe is moved, enabling arterial vessel detection and localization. A subregion within the detected arterial vessel and a beam steering angle may be autonomously determined for spectral Doppler data collection, enabling the measurement of hemodynamic measures associated with the arterial vessel. Example apparatus for securing the probe to the patient and facilitating probe positioning to search for a target vessel are disclosed.

The invention provides a method and a system for accurately regulating and controlling waste gas denitration air quantity of a glass melting furnace. According to the method, an ultrasonic Doppler sensor group is arranged around a glass melting furnace flue, ultrasonic beams are synchronously emitted to collect flow velocity pulsation data required by exhaust gas denitration air volume, time sequence waveforms are decomposed to generate multi-dimensional frequency characteristics, and the multi-dimensional frequency characteristics are aggregated into a multi-dimensional flow velocity vector representing a flow field state; vector deviation is synchronously corrected through space coordinate alignment and a time sequence, and difference variable quantity is extracted and fused to generate a flow field thermodynamic diagram; establishing a time-space correlation model of the multi-dimensional flow velocity vector and the thermodynamic diagram, predicting an air volume adjusting threshold value meeting the denitration requirement, and converting the air volume adjusting threshold value into a fan rotating speed control signal to drive an execution mechanism; and according to waste gas pulsation response data caused by fan rotating speed change and thermodynamic diagram updating frequency relevance, multi-dimensional flow velocity vectors are dynamically adjusted to form closed-loop regulation and control. According to the application, the dynamic demand of the denitration air volume and the millisecond-level closed-loop response executed by the fan are realized, the flue gas purification efficiency is improved, and the energy consumption is reduced.

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

The invention discloses a non-contact method for measuring a three-dimensional flow velocity field in a pipeline based on acoustic Doppler, and the method comprises the steps: transmitting a focused sound beam into the pipeline, receiving an echo signal reflected by a scatterer in fluid, and generating a Doppler echo signal set covering different angles and depth positions; performing pulse compression and time-frequency analysis on the Doppler echo signal set, and calculating the sight flow velocity component of each point along the sound beam direction; calculating a three-dimensional flow velocity vector of each sampling point based on the coordinate position of each space sampling point and the corresponding sight line flow velocity component, and realizing decoupling of the flow velocity direction and size; according to the spatial distribution of the three-dimensional flow velocity vector on the section of the pipeline, a three-dimensional flow velocity field model in the pipeline is generated through interpolation fitting, and section flow and flow state characteristic parameters are calculated according to the model. According to the embodiment of the invention, the limitation that only two-dimensional or one-dimensional flow velocity can be measured in a traditional method can be broken through, and the spatial resolution and measurement precision of flow velocity field reconstruction in a complex flow state are improved.

The invention discloses a GNSS (Global Navigation Satellite System) signal sparse compression capture method for a low-correlation measurement matrix, which comprises the following steps of: firstly, constructing a code phase matrix and a frequency offset matrix, and carrying out sparse transformation on a downsampled GNSS signal to obtain a correlation matrix; the method comprises the following steps of: firstly, carrying out iterative optimization on a measurement matrix by taking a Gramb matrix as a matrix, then taking a Frobenius norm of a difference between the Gramb matrix and an equiangular tight frame matrix as a target function, alternately using singular value decomposition (SVD) and a shrinkage operator to carry out iterative optimization on the measurement matrix, and carrying out compression measurement on a correlation matrix through the optimized measurement matrix. Secondly, a correlation matrix of compression measurement is quickly and accurately reconstructed by using a least square operator and an orthogonal matching pursuit algorithm; and finally, when the peak value ratio of the primary peak to the secondary peak of the reconstructed correlation matrix is greater than a threshold value, outputting code phase time delay and Doppler frequency offset corresponding to the primary peak. And if the ratio of the primary peak value to the secondary peak value of the reconstructed correlation matrix is smaller than the threshold value, capturing the GNSS signal again. According to the method, the maximum correlation coefficient and the average correlation coefficient of the measurement matrix can be reduced, the GNSS signal capturing sensitivity is improved, and hardware resources in the signal capturing process in a GNSS receiver can be reduced.

The invention relates to a radio frequency fingerprint identification method based on knowledge and data hybrid driving, which comprises the following steps of: on one hand, learning channel characteristics of an input signal by using a SupportNet model, and carrying out equalization processing on the signal so as to remove the influence of Doppler frequency offset on the signal and obtain a signal irrelevant to a channel; on the other hand, radio frequency fingerprint features are extracted in parallel through the knowledge graph and the one-dimensional convolutional network, the radio frequency fingerprint features extracted in parallel through the knowledge graph and the one-dimensional convolutional network are spliced, feature recombination is achieved through the attention module, enhancement of effective features and weakening of irrelevant features are achieved, and finally classification is conducted through the classifier. Therefore, the radio frequency fingerprint identification performance in a high-speed moving scene is improved. According to the method, the signal is subjected to equalization processing by using a SupportNet model, radio frequency fingerprint identification is realized by combining a convolutional neural network and a knowledge graph, and the method is suitable for a high-speed mobile channel.

The invention provides a low-power-consumption cooperative sewer water body integrated monitoring method. The method comprises the following steps: carrying out model selection and deployment on sensing node hardware of an adaptive scene; a low-power-consumption internet of things network topology and power supply design; a time-sharing triggering acquisition strategy of the multi-modal data is carried out; node-level environment self-adaptive data calibration is carried out; node-level flow velocity-stink association anomaly recognition is carried out; carrying out network-level data fusion and validity verification; collaborative traceability, diffusion simulation and linkage control are carried out. According to the invention, the problems of data distortion, difficulty in source tracing of pollution sources, short equipment endurance and response lag caused by independent collection of flow and stink and environmental interference in traditional sewer monitoring are solved; the integrated effect of ultrasonic Doppler and electronic nose cooperative monitoring, environment self-adaption accurate calibration, odor source rapid positioning and diffusion simulation and low-power-consumption and long-endurance linkage control is achieved.

The invention relates to the technical field of abnormal behavior recognition, in particular to an abnormal behavior multi-mode recognition method and system for a smart community. Comprising the following steps: multi-modal data acquisition and preprocessing: synchronously acquiring spatio-temporal dynamic data of a target area through a millimeter wave radar, an infrared sensor, a microphone array and a panoramic camera deployed in a community, wherein the spatio-temporal dynamic data comprises a human body motion track, temperature field distribution, environment voiceprint characteristics and a visual image sequence; wherein the millimeter-wave radar adopts a frequency modulation continuous wave system to sample micro-Doppler characteristics of a human body, the infrared sensor realizes temperature field reconstruction through the pyroelectric array, the microphone array collects voiceprint signals through the array structure, and the panoramic camera collects a high-frame-rate image sequence; and environment interference coupling correction: aiming at acoustic reflection characteristics of different materials in the community, and combining an illumination abrupt change rate, an object reflectivity and an air humidity parameter, the method can improve the recognition accuracy and robustness in a complex community environment.