16 results about "Doppler velocity" patented technology

The present application relates to radar signal processing technical field, specifically provide a kind of staggered pulse repetition interval time-frequency domain dual-polarized radar detection variable estimation method, comprising: in frequency domain, the estimation of echo signal-to-noise ratio, reflectivity factor, differential reflectivity of horizontal / vertical polarization based on power spectral density;And the estimation of average Doppler velocity and velocity spectrum width;In time domain, after ground clutter filtering based on odd-even pulse, respectively, odd-even pulse correlation parameter estimation is carried out, so that two detection variables of dual-polarized radar correlation coefficient and differential propagation phase shift of odd-even pulse are obtained respectively, then odd-even combination can obtain the estimation result of accurate correlation coefficient and differential propagation phase shift.The present application realizes the accurate estimation of dual-polarized radar multi-class detection variable, ensures that estimation result is not disturbed by ground clutter interference, simultaneously adapts single pulse repetition interval and staggered pulse repetition interval two working modes, improves the reliability and applicability of radar detection.

Embodiments of the present disclosure disclose a SPP positioning model construction method and device based on factor graph optimization. The specific implementation of the method comprises: constructing a variable node set of a factor graph structure, wherein the to-be-estimated state quantity of each variable node in the variable node set at an epoch includes three-dimensional coordinates of a receiver and four parameters related to clock bias of the receiver; constructing a pseudorange factor set according to the variable node set, wherein the pseudorange factor set includes at least four pseudorange factors; correlating the position parameters between two adjacent epochs in each epoch in an observation window to construct a Doppler velocity factor, obtaining a Doppler velocity factor set, wherein the Doppler velocity factor is a binary factor; constructing a graph optimization cost function according to the pseudorange factor set and the Doppler velocity factor set, and obtaining a SPP positioning model. The implementation can improve the GNSS positioning accuracy in a complex environment.

This invention discloses a posture optimization and adjustment system and method for earth pressure balance tunnel boring machines (TBMs) in hydraulic engineering, relating to the field of posture optimization and adjustment technology for earth pressure balance TBMs in hydraulic engineering. It includes a groundwater data acquisition module, a posture data acquisition module, a posture optimization processing module, and a posture optimization adjustment module. The groundwater data acquisition module and the posture data acquisition module acquire groundwater flow velocity data, posture deviation data, earth chamber pressure data, and TBM propulsion data. The posture optimization processing module is used to obtain the degree of influence of groundwater flow velocity on the posture deviation data, earth chamber pressure data, and TBM propulsion data. This invention combines Doppler velocity detection technology, acceleration acquisition technology, sensor technology, synchronous clock source technology, and modern information technology to achieve comprehensive monitoring of the influence of groundwater flow velocity on the posture optimization and adjustment of the earth pressure balance TBM.

The application discloses a radar moving working clutter suppression method, S1 calculates the real-time vehicle speed compensation value of the working beam of the radar installation platform when moving, and realizes moving working resource scheduling. S2 compensates the echo signal of the radar according to the real-time vehicle speed compensation value, then detects the original point track of the radar detection target by means of phase comparison accumulation of the compensated echo signal, selects a fixed reference point in the geodetic coordinate system, and constructs a moving amplitude clutter map based on the original point track and the fixed reference point, wherein the moving amplitude clutter map has target point tracks. S3 establishes a false track judgment model based on time series Doppler velocity matching filtering by means of the historical motion track of the radar installation platform and the target point track, so that the judgment, marking and elimination of the fixed clutter point track and the false track are realized.

The application discloses a ROV opening position anti-disturbance control system and method based on long baseline integrated navigation, and the system comprises a long baseline positioning auxiliary module, a disturbance observation and control module and an execution module; the long baseline positioning auxiliary module obtains an absolute position through a transponder array, obtains a relative position through a strapdown inertial navigation system and a Doppler velocity meter, and outputs a position through an adaptive unscented Kalman filter; in the disturbance observation and control module, an extended state observer takes the fused position as input to observe total disturbance, a sliding mode controller generates control force based on position deviation and corrects feedforward through disturbance estimation, and a thruster dynamic compensation unit compensates cavitation and dead zone characteristics; the execution module distributes the compensated control force to a vector thruster through a construction-analysis method. The application solves the problems of navigation accuracy and frequency contradiction in deep opening operation, observer miscompensation and instability caused by non-ideal characteristics of a thruster.

The application discloses a kind of based on deep learning's millimeter wave radar point cloud data iterative registration method, this method includes: obtaining first to be matched point cloud data and second to be matched point cloud data;Determine the n different neighborhood of each point in these two point cloud data;According to the spatial coordinates of each point, polar coordinates, the Doppler velocity of each neighborhood point of each point, the PPF vector between each point and each neighborhood point, and the point feature extraction network trained, determine the fusion point feature of each point;The spatial coordinates, Doppler velocity and point cloud mark of each point in these two point cloud data are input into the registration parameter prediction network trained, and the point cloud registration parameter is predicted;The point cloud mark of each point is used to indicate the point cloud data that the point belongs to;Based on point cloud registration parameter, the fusion point feature of each point in these two point cloud data, determine transformation parameter;Based on transformation parameter, these two point cloud data are registered.

The application discloses a single-antenna abnormality detection and correction method based on Doppler velocity measurement, and relates to the technical field of integrated navigation, and has the technical scheme as follows: original observation data of GNSS is acquired, and the original observation data at least includes Doppler velocity measurement information; carrier velocity information at the current moment is solved based on the Doppler velocity measurement information; attitude information of the current carrier is acquired; whether the carrier is in an abnormal motion state is judged based on the carrier velocity information and the attitude information; an NHC model is constructed; according to the judgment result, the constraint strategy of the NHC model is adjusted, the measurement information is constructed based on the adjusted constraint strategy, the integrated navigation filter used for estimating the navigation state of the carrier is observed and updated by using the measurement information, and the navigation error of the carrier is corrected. The application judges the abnormal state by using the Doppler velocity measurement information and adaptively adjusts the NHC constraint strategy, so that the precision of the single-antenna integrated navigation under abnormal working conditions is improved without increasing the hardware cost.

The present disclosure relates to a vehicle speed measurement method, a storage medium and an electronic device to solve the problem that the speed sensor and the accelerometer do not accurately measure the speed of the vehicle. The method comprises: obtaining a first speed measured by a first speed sensor and a second speed measured by a second speed sensor, one of the first speed sensor and the second speed sensor being a Doppler speed sensor and the other being a Hall speed sensor; determining a first proportion value corresponding to the first speed and a second proportion value corresponding to the second speed according to at least one of the slope, the curvature radius, the environmental humidity and the predicted speed of the current line of the vehicle, the predicted speed being determined based on the first speed and the second speed; and determining the sum of the product of the first speed and the first proportion value and the product of the second speed and the second proportion value as the measured running speed of the vehicle.

The application provides a 4D millimeter wave radar-based pose graph SLAM calculation method and system, comprising the following steps: S1, ground point cloud is extracted, two continuous frames of point clouds are compared, ghost points and random points under the ground are removed; S2, the linear velocity and angular velocity of the device are estimated by using the Doppler velocity information of the 4D radar point cloud; S3, the pose graph is estimated and constructed by using the relative pose transformation, the point cloud registration based on the normal distribution transformation, the pre-integration is performed by using the estimated device velocity, the loop detection is performed, and the optimal pose is estimated by using the graph optimization. In order to achieve better accuracy in the case of sparse point cloud, the pre-integration is performed on the estimated self-vehicle velocity, additional relative pose estimation is obtained, the loop detection is introduced, the places that are reached again are identified, the historical poses are optimized from the global perspective, the cumulative drift is reduced, and accurate and robust mapping and positioning are realized.

An aircraft-based system for providing forward-looking terrain profiling and downward-looking altimetry via a single active electronically scanned array (AESA) orients the AESA through a sequence of desired directions, e.g., according to a predetermined scan pattern. At each desired direction, the AESA scans for ground-based targets, determining a range and Doppler velocity to each detected target. The AESA additionally orients downward, e.g., during a dedicated altimetry frame and with the assistance of inertial sensors to determine the orientation of the AESA, to scan terrain directly below the aircraft and provide a precise estimate of the altitude of the aircraft. Based on the determined ranges and velocities, the radar system determines a pointing angle and vertical / horizontal distances between the aircraft and each identified ground-based target.

The application discloses a kind of polar underwater vehicle self-adapting temperature control confidence combination navigation method, belong to navigation and control technical field, for polar underwater vehicle combination navigation, including combination navigation system initialization, mechanics solution and state prediction of strapdown inertial navigation system, temperature monitoring and power consumption control, parallel sub-filter processing, according to Doppler velocity data confidence score calculation, main filter carries out global state optimal estimation.The application is switched to ice layer reference surface automatically when missing in submarine reference surface by bidirectional Doppler velocity meter symmetrical layout, or optimal weighted fusion is carried out when both reference surfaces are available, which significantly improves the robustness and long-time high-precision operation capability of the system under complex hydrogeological conditions;Through dynamic duty cycle adjustment and pulse heating strategy, the performance stability of the sensor and the collaborative optimization of the low-power operation of the system are realized.

This invention provides a blind zone relay tracking method and system based on heterogeneous data spatiotemporal calibration. The method includes: acquiring images and radio frequency (RF) signals at the blind zone entrance; calculating the cross-covariance between the image optical flow velocity and the RF Doppler velocity to anchor the visual target to RF hardware features and generate a tracking identifier; within the blind zone, using a joint probabilistic data interconnection algorithm to perform weighted fusion of signal echoes based on spatial distance and RF feature similarity to achieve RF tracking; and at the blind zone exit, using a manifold alignment algorithm to compare the topological distance between RF trajectory fluctuations and the visual motion displacement of candidate objects in low-dimensional space to reconfirm their identity. This invention solves the technical problem of traditional tracking methods relying solely on easily camouflaged and confused visual tracking, leading to the interruption of the tracking chain in the blind zone.

The application provides a device and method for obtaining angle information of a static target and a simultaneous localization and mapping system. The device comprises: an FMCW sensor, which is used for performing two-dimensional fast Fourier transform on a received echo signal and then performing constant false alarm processing to obtain a range-Doppler spectrum including Doppler velocity data of the static target; and a processor, which is used for performing vector calculation according to a travel speed of the sensor and the Doppler velocity data, converting the range-Doppler spectrum into a range-angle spectrum, and then obtaining horizontal angle information of the static target relative to the sensor. The application can realize high-precision angle measurement of the static target at a low cost and is convenient for popularization and application in the fields of automatic driving, automatic parking, robot navigation and the like.

The application discloses an airborne weather radar wind shear detection speed unblurring method, complete radar waveforms are generated based on A-wave and B-wave grouping waveforms; after receiving radar echo for digital sampling, rearrangement processing is carried out, and data of fast-slow time dimensions of A-group and B-group waveforms are obtained; then, along the fast time dimension, matching filter processing is carried out, and the fast time dimension is converted into a distance dimension; after Doppler components caused by the speed of an airplane itself are compensated, along the slow time dimension, FFT transformation processing is carried out, and distance-speed dimension spectrum data are obtained; along the distance dimension, first moment calculation processing is carried out on Doppler velocity spectrum for each distance gate to obtain blurred wind speed measurement values, and corresponding A-wave and B-wave data are extracted; unblurring operation processing is carried out based on the A-wave and B-wave data to obtain wind speed measurement values. The application has extremely small calculation amount, and can complete speed unblurring in a signal processing link, and does not affect the data refresh rate of wind shear detection.

The application provides a method and device for improving strain displacement precision of a medical color ultrasound equipment, wherein the method comprises the following steps: S11, front-end cross-transmitting and receiving multi-angle ultrasonic wave carrier signals to obtain baseband original echo signals in a user interested area; S12, sparsely sampling the baseband original echo signals before and after deformation along each angle scanning line direction; S13, obtaining original baseband echo signals in the same direction before and after deformation according to time intervals before and after deformation; S14, point-by-point Doppler velocity estimation is performed on multi-frame sparsely sampled baseband signals in the same angle and different time along the scanning line and time direction; S15, calculating accurate displacement frames according to the displacement sequence frames in each angle; and S16, obtaining displacement sequence frames in each angle according to the Doppler velocities in each angle. The application uses a cross multi-angle scanning mode to calculate tissue velocity and displacement by using the Doppler principle, and improves the precision of tissue displacement on the basis of minimizing data amount.

This application designs a rotation-based heterogeneous information cross-fusion scheme to enhance the spatial structure information of millimeter-wave radar inter-frame spectra and alleviate the positional ambiguity caused by limited angular resolution in spatial landmark feature extraction. A spatially consistent landmark extraction and association scheme is designed to extract robust and dense landmark feature point clouds from millimeter-wave radar spectra rich in external spatial information, effectively reducing the impact of millimeter-wave point cloud sparsity and clutter. A differentiable ego-velocity estimation method is proposed to accurately extract sub-pixel-level radial velocities from Doppler spectra and precisely estimate ego-velocities. A loss function based on geometric, velocity consistency, and Doppler velocity constraints is constructed to train the landmark extraction network in a self-supervised manner, thereby achieving accurate localization and robust mapping. This application can seamlessly adapt to complex and extensive traffic and driving environments without ground truth supervision of localization, and achieve stable and reliable state estimation and landmark extraction.