174 results about "Doppler velocity" patented technology

The invention discloses a robot obstacle avoidance method and system based on millimeter wave radar sparse point cloud, and relates to the technical field of obstacle avoidance recognition. A robot obstacle avoidance system based on millimeter wave radar sparse point cloud comprises a point cloud acquisition module, a negative obstacle identification module, a weak obstacle identification module, a point cluster identification module, a risk map module, a tentative verification module and an obstacle avoidance decision module. According to the invention, suspected obstacle point clusters are extracted based on a reflection intensity threshold and a spatial proximity relation in an enhanced point cloud, a theoretical parallax model of a real static obstacle is constructed under the constraint of a robot motion trajectory, and Doppler velocity distribution of each frame is combined with a static obstacle Doppler physical law for comparison. And classifying the point clusters which do not meet the multi-view geometric consistency or Doppler physical law, and distinguishing multipath false point clusters from dynamic point clusters.

The invention discloses a heterogeneous sensor fusion method and system for dynamic covariance optimization, and the method comprises the steps: constructing a multi-source heterogeneous sensor network which comprises an underwater inertial navigation unit, a Doppler velocity sensor, an ultra-short baseline positioning system, a submarine topography matching device and a geomagnetic gradient detector; the method comprises the following steps: designing a distributed integrated navigation system by adopting a hierarchical fusion architecture, establishing a sensor confidence coefficient dynamic evaluation model based on online estimated error covariance matrix eigenvalue analysis, carrying out state prediction on a local filter level by applying Kalman filtering, and then carrying out measurement updating by adopting a novel variational Bayesian algorithm; a sensor autonomous switching and adaptive weighted dual-mode adjustment mechanism is developed on the main filter level, and self-healing improvement of navigation precision in a non-stationary environment is realized, so that the problems of dynamic reliability evaluation and fusion efficiency optimization in underwater multi-sensor multi-source navigation are solved.

The invention relates to the technical field of radar identification, and discloses a radar identification and collision early warning method and system for a two-wheeled vehicle, and the method comprises the steps: carrying out the synchronous collection of a radar echo signal and a vehicle body motion signal in a backward detection region of an electric two-wheeled vehicle, doppler frequency shift data, radar reflection sectional area data, radial distance data, reflection signal intensity data and motion state data are obtained; carrying out vehicle body motion compensation and time sequence variance calculation to obtain first static and dynamic target classification information; carrying out reflection characteristic calculation to obtain a candidate target data set; and performing consistency verification on the radial distance change rate and the Doppler velocity to obtain second static and dynamic target classification information, and outputting a target early warning signal in combination with the second static and dynamic target classification information. And the timeliness and reliability of collision early warning are improved.

The invention discloses a composite precipitation cloud layer identification method based on a laser radar-cloud radar, and the method comprises the steps: obtaining the observation data of the laser radar and the cloud radar, and carrying out the data matching of the observation data; processing a signal of the laser radar in a height interval of 18-20 km to obtain a preprocessed laser radar signal; performing laser radar cloud boundary identification based on a VED algorithm, and endowing different laser radar cloud scores according to the signal attenuation rate and the signal gradient; removing earth surface clutters by using a threshold method based on observation of spectral width and Doppler velocity; carrying out cloud radar significant echo recognition based on a threshold method, and determining the cloud score of the cloud radar according to different reflectivity factor signal intensities; determining a light rain area and a heavy rain area according to the Doppler velocity; cloud layer boundary information and a hairy rain area are obtained through cloud layer recognition result fusion, and cloud layer recognition and rainfall area recognition are completed; according to the invention, the accuracy of weather prediction is improved.

The invention provides a synchronous positioning and mapping method for underwater pipeline detection, and belongs to the technical field of underwater robot navigation and positioning. In order to solve the problems of limited illumination, strong echo interference, high structural repeatability and the like in a seawater pipeline environment, the invention provides a factor graph optimization-based tight coupling pose estimation framework fusing a two-dimensional imaging sonar, a Doppler velocity meter DVL and an inertial measurement unit IMU. Through joint constraint and optimization of multi-source sensing information, the method can realize high-precision positioning and continuous mapping of the ROV in an environment with extremely low visibility and a complex pipeline structure, and effectively improves autonomy and data reliability of an underwater inspection process. The method is clear in structure, easy and convenient to implement, high in calculation efficiency, capable of stably running on a conventional ROS platform and suitable for various types of underwater pipeline detection and inspection tasks.

The invention provides a broadband beam forming acoustic Doppler velocity measurement system and method based on time delay control, which can transmit and receive broadband signals and solve the problem that the measurement precision of the existing acoustic Doppler velocity measurement system is influenced by bandwidth. The velocity measurement system comprises a transducer module, a beam forming module and a conversion module, the transducer module comprises a planar transducer array and an impedance matching module connected with the planar transducer array; the transducer module is in signal connection with the beam forming module through the conversion module, and the beam forming module is used for performing time delay compensation and weighting processing on a received signal; and the conversion module is used for converting the echo signal acquired by the transducer module into a digital signal and inputting the digital signal into the beam forming module, or converting a to-be-transmitted signal received from the beam forming module into an analog signal and transmitting the analog signal through the transducer module.

The invention belongs to the technical field of navigation, and discloses an inertial navigation method and system based on dual modes and a medium, the dual modes comprise a first navigation mode and a second navigation mode, the first navigation mode adopts a first combined navigation mode formed by combining an inertial unit with an ultra-short baseline acoustic positioning unit and a Doppler velocity measurement unit, and the second navigation mode adopts a second combined navigation mode formed by combining an ultra-short baseline acoustic positioning unit and a Doppler velocity measurement unit. The navigation mode II adopts a second combined navigation mode of combining an inertial unit and a geomagnetic measurement unit. The method comprises the following steps: acquiring the depth of the submersible at the current position; and updating the current position of the submersible in real time by adopting the navigation mode I and / or the navigation mode II according to the depth of the submersible at the current position. The method has high positioning accuracy.

The invention discloses a mapping method and device based on a 4D millimeter wave radar and a computer readable medium, and the method comprises the steps: carrying out the noise reduction of a 4D millimeter wave radar point cloud based on the coordinate information and RCS information of the 4D millimeter wave radar point cloud in a preset sliding window; based on the Doppler velocity, performing dynamic point cloud filtering processing on the preprocessed point cloud to obtain static point cloud; and for any current frame point cloud in the static point clouds, performing conversion processing on the current frame point cloud based on the pose conversion matrix, and performing feature point registration on the converted current frame point cloud and a previous frame sub-map to generate a current frame sub-map. According to the embodiment of the invention, based on RCS information and Doppler velocity, filtering processing is carried out on point clouds collected by a 4D millimeter wave radar; and feature point registration is carried out on the static point cloud obtained after filtering to form a local sub-map. Therefore, the point cloud in the target scene can be subjected to high-precision registration, so that high-precision positioning of the unmanned equipment is realized.

The invention provides an outdoor cross-modal robust positioning and navigation method for extreme severe weather, and relates to the field of online positioning and navigation of mobile robots. The method comprises the following steps: acquiring and preprocessing data; generating a path point set based on a CMR network, perfecting the path point set through local trajectory fitting and error optimization, and constructing a path point relative pose measurement-topology hybrid map; motion prior estimation is carried out based on Doppler velocity, effective matching prior estimation is generated in combination with LiDAR odometer information, cross-modal pose estimation is carried out through a CMR network, and a pure tracking strategy and PD controller path point tracking are adopted; and geometric and intensity alignment is carried out on the forward 4D millimeter wave radar point cloud and the omnidirectional 3D laser radar point cloud through a CMR network, a rotation matrix and a translation vector are output, and accurate positioning is completed. According to the invention, the sensing and positioning defects in extreme weather in the prior art are overcome, and the positioning precision and robustness are improved.

The invention discloses a Doppler blood flow velocity estimation method based on high-frequency pulse differential frequency, and solves the problems of velocity estimation resolution reduction and artifacts caused by alternate transmission of a B mode and Doppler pulses in an ultrasonic dual-mode system. The method comprises the following steps: transmitting a high-frequency broadband ultrasonic signal compatible with B-mode imaging; the method comprises the following steps: receiving a superficial blood vessel echo signal, performing time domain sampling, converting into a discrete signal, extracting a narrow-band frequency spectrum through frequency sampling, and generating a low-frequency equivalent signal by using a multi-frequency-point differential frequency technology; calculating a covariance matrix of each signal, performing average weighting to remove artifacts, and generating low-frequency equivalent covariance data; and estimating the blood flow velocity through eigenvalue decomposition and spectral peak search. According to the method, two pulses do not need to be transmitted alternately, resolution reduction and artifacts are avoided, Doppler velocity estimation precision is remarkably improved, integrated waveform design is supported, and hardware implementation is simplified.

The invention relates to the technical field of medical instrument volume detection, and discloses a medical instrument internal volume detection system. A continuous wave and a pulse modulation signal are simultaneously transmitted through an annular phased array microwave antenna array, three-dimensional dielectric constant distribution is reconstructed by adopting a compressed sensing algorithm, and Doppler time-frequency domain characteristics are extracted through short-time Fourier transform; and inputting the phase gradient field and Doppler velocity field features into a convolutional neural network to generate a four-dimensional space-time volume evolution model, separating a macroscopic volume trend and a microcosmic pulsation component by adopting an adaptive Kalman filtering algorithm, and predicting an abnormal hemodynamic event through a long-short-term memory network. The technical problem of real-time precise detection of the multi-dimensional volume parameters of the blood circulation medical instrument under the complex pulsating flow condition is solved, and accurate evaluation of the instantaneous volume value, the pulsation amount and the pulsating frequency spectrum and early warning of abnormal events are achieved.

The present invention discloses a space-time inversion method for ocean wave parameters using a shipborne coherent S-band radar, comprising the following steps: obtaining a space-time Doppler spectrum and extracting the average Doppler frequency deviation; estimating a space-time radial velocity sequence and converting it into a wavenumber frequency spectrum; estimating the wavefield energy and group line energy distribution and designing an adaptive filter; filtering the wavenumber frequency spectrum and reconstructing a space-time radial Doppler velocity sequence; estimating the wavenumber directional spectrum; repeating the above process to obtain six wavenumber frequency spectra and inverting an undirected ocean wave spectrum; and finally inverting the ocean wave parameters. This method addresses the impact of breaking waves and ship motion on the accuracy of ocean wave parameter inversion. It not only retains the advantages of shore-based coherent microwave radar but also overcomes its shortcomings in spatial scalability and temporal continuity, significantly improving the robustness and accuracy of ocean wave parameter inversion using shipborne coherent S-band radar.

A computer-implemented method for estimating a travelling speed of a wireless device in a wireless communications network, where the wireless device has transmitted a signal sequence to a network node via two or more signal paths. The method includes obtaining data indicative of a Doppler speed difference between respective multipath components of the signal sequence transmitted via the two or more signal paths; obtaining data indicative of direction of departure, DoD, (nUE,P1, nUE,P2) of the two or more signal paths at the wireless device; and estimating the travelling speed of the wireless device based on the data indicative of the Doppler speed difference and the data indicative of DoD.

The invention discloses an under-water flow tumble detection system based on multi-scale fusion and decision, which comprises the following steps of: acquiring radar signals in a detection area by utilizing a millimeter wave radar, constructing a distance Doppler spectrum, calculating a water flow dynamic clutter index based on energy distribution statistical characteristics, identifying a background noise type and dynamically generating a detection threshold; target point cloud extraction under a complex dynamic water flow background is realized; the method comprises the following steps: performing track initialization and state updating by constructing a two-stage gating and evidence judgment framework, executing online parameter self-adaption and target physical size estimation, extracting time sequence characteristics such as a centroid position and Doppler velocity, and constructing a characteristic vector; and establishing a finite state machine model based on the feature vectors, identifying state transition, fall confirmation and state rollback conditions, and outputting a fall judgment result or a rollback result. According to the invention, accurate identification and dynamic determination of a fall event in a wet, slippery and water flow complex environment are realized.

A survey system including a multibeam echo sounder having a projector array and a hydrophone array uses a multi-component message to ensonify one or more fans to estimate a Doppler velocity.

The invention relates to the technical field of millimeter-wave radar and sensor calibration, in particular to a multi-millimeter-wave radar rapid calibration method and device and electronic equipment, and the method comprises the steps: constructing a first motion model of a millimeter-wave radar according to the Doppler velocity and space coordinates of a point cloud, and extracting a stationary target point cloud from the point cloud data of the multi-millimeter-wave radar, estimating the motion speed of each millimeter-wave radar according to the stationary target point cloud, constructing a second motion model of the millimeter-wave radar based on the external parameters between the radars, estimating the motion speed relationship between the radars together with the motion speed of the millimeter-wave radar, and obtaining the motion parameters of the target platform where the multiple millimeter-wave radars are located; and on the basis of the motion data of the target platform where the multi-millimeter-wave radar is located and the motion speed relationship between the radars, calibrating external parameters between the radars of the multi-millimeter-wave radar. Therefore, the problem that the high-precision requirement of the unmanned system in a dynamic environment is difficult to meet due to response delay when external parameters change in related technologies is solved.

The invention provides an autonomous underwater robot cluster cooperative positioning method and system, and the method comprises the steps: carrying out the interaction of the pose information of a master underwater robot and a slave underwater robot through underwater acoustic communication, calculating the relative distance between the master underwater robot and the slave underwater robot through underwater acoustic two-way distance measurement, and enabling the navigation system of the slave underwater robot to be an inertial navigation system assisted by a Doppler speedometer. The navigation information and the underwater sound ranging information are fused, so that the navigation reference in the underwater robot cluster is unified with the main underwater robot, and the cooperative positioning of the underwater robot cluster is completed.

A radar data processing device and method is provided. The method generates a radar image map, predicts a region of interest (ROI) based on the generated radar image map, senses radar data with a radar sensor, identifies the sensed radar data based on steering information, adjusts the steering information based on the predicted ROI, and determines direction-of-arrival (DoA) information corresponding to the sensed radar data based on the adjusted steering information. The radar data processing device may locally adjust at least one of a range resolving power, an angular resolving power, or a Doppler velocity resolving power based on the ROI predicted based on a radar image map, and generate an accurate radar data processing result of a major region.

The invention discloses a coherent radial velocity spectrum target detection method based on a backtracking filter. The method comprises the following steps: constructing a sea surface echo model and a multi-frame joint detection problem; the method comprises the following steps: based on a sea surface echo model and a multi-frame joint detection problem, performing coherent accumulation on a radar receiving pulse sequence, and calculating test statistics of intra-frame coherent accumulation under each frame, each distance unit and each radial speed; based on the inconsistency of the sea clutter structural texture between the slow time Doppler velocity and the frame time radial velocity and the velocity consistency of the target on two time scales, inter-frame accumulation is carried out on the test statistics of each frame, each distance unit and each radial velocity in a distance-frame time plane along the radial velocity direction; constructing a coherent radial velocity spectrum; and in an inter-frame accumulation process, replacing a linear search accumulation mode of the coherent radial velocity spectrum between scanning by using the backtracking filter bank to obtain a coherent radial velocity spectrum based on the backtracking filter bank, and carrying out target detection by using the coherent radial velocity spectrum.

The application provides a conveyor speed detection method, device and equipment based on a dual-antenna RFID. The method comprises: tracking and processing an RFID tag by using a first antenna, and recording a first phase sequence of the RFID tag; tracking and processing the RFID tag by using a second antenna, and recording a second phase sequence of the RFID tag; determining a phase difference between the first phase sequence and the second phase sequence, and determining a phase difference speed according to the phase difference; determining a Doppler speed according to movement data of the RFID tag; fusing the phase difference speed and the Doppler speed by using a Kalman algorithm, determining a final conveyor belt speed, and outputting the final conveyor belt speed. The phase difference speed is determined according to the phase difference between the phase sequences of the two antennas. The Doppler speed is also determined. The phase difference speed and the Doppler speed are fused by using the Kalman algorithm, and the final conveyor belt speed is determined, so that the conveyor belt speed is accurately detected with high precision.

The present application relates to an apparatus for determining the ego-motion of a radar apparatus, the apparatus configured to: process radar-point-cloud information comprising a plurality of points by neural network models, the processing comprising: pointwise mapping the features thereof to a greater number of mapped-features to provide mapped-radar-point-cloud information, determining a global feature vector indicative of characteristics of the mapped-radar-point-cloud information, generating a feature matrix wherein each point therein is characterized by a feature-set based on a combination of the features, the mapped-features and the global feature vector, determining a pointwise-weight representing a likelihood that the point represents a stationary object in the space, a pointwise-offset comprising a correction to be applied to the Doppler velocity measurement to at least reduce the Doppler velocity measurement for points having a greater than expected Doppler velocity, and providing an estimate of the motion of the radar apparatus.

The present invention discloses a fusion positioning method. Based on the three-dimensional position vector, Doppler velocity measurement result vector, and position change value vector of the GNSS module positioning results, the differential pressure value results based on the barometer, and the pedestrian relative position vector based on the accelerometer, the three-dimensional position vector, Doppler velocity measurement result vector, position change value vector, differential pressure value results, and pedestrian relative position vector are fused on a cloud server using Kalman filtering to obtain high-precision positioning information, forming a unified data processing method, and capable of providing accurate position information of personnel in real time. In short, the present invention has the advantages of advanced algorithm, high stability, and high precision.

The application relates to the technical field of radar measurement, in particular to a high-precision radar speed measurement method in a tunnel for intelligent traffic. The method matches initial point cloud data of different radars by using a matching method, determines information weight values corresponding to each radar in combination with point cloud quality, and further determines effective point cloud data. The point cloud speed and the Doppler speed are further weighted and fused to obtain movement information of each vehicle area. The interference degree of the vehicle area at each moment is determined, and then the influence degree of each historical moment can be determined in combination with information between the historical moment and the real-time moment. The predicted movement information is determined in combination with the influence degree, and the movement information of the preceding vehicle is used for adjustment. The application eliminates the influence of the multipath effect in the tunnel, and realizes effective speed measurement and accurate prediction of each vehicle.

According to the present invention: a continuous sine wave signal is emitted toward an object serving as a target; a reflected wave comprising the sine wave signal reflected by the object is received; a frequency component of the sine wave signal that has been Doppler-shifted in accordance with the relative speed of a moving body and the object is extracted from the received reflected wave and output as a Doppler shift signal; a plurality of Doppler shift signals having a second duration are generated by cutting out, at a plurality of mutually different timings within a predetermined time period, a part of the Doppler shift signal having a predetermined first duration corresponding to the predetermined time period; a Doppler velocity for each of the Doppler shift signals having the first and second durations are calculated on the basis of the Doppler shift signals having the first and second durations; and the speed of the moving body in the current time period is determined on the basis of the calculated Doppler velocities of each of the Doppler shift signals having the first and second durations.

The invention provides a positioning method and electronic equipment, and is applied to the technical field of terminal equipment. The positioning method comprises the following steps: in response to relative motion of the electronic equipment and a target object, determining a motion velocity vector of the electronic equipment; determining a transmitting frequency of transmitting a signal to the target object by the electronic equipment, and a receiving frequency reflected by the target object based on the transmitting frequency and received by the electronic equipment; according to the motion velocity vector, the transmitting frequency and the receiving frequency, Doppler velocity is determined, and the Doppler velocity represents a relative velocity scalar between the electronic device and the target object generated by the Doppler effect; and determining position information of the target object relative to the electronic equipment according to the motion velocity vector and the Doppler velocity.

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.

The invention discloses a tunnel concrete pouring quality monitoring method, equipment and a medium, belongs to the field of artificial intelligence and the technical field of tunnel safety, and is used for solving the problems that in the existing tunnel concrete pouring process, the flow velocity detection of concrete slurry is inaccurate, and the working efficiency is low. And the pouring quality is affected by structural defects caused by uneven flow velocity. The method comprises the following steps: carrying out global and local edge feature modulation processing on an edge contour of a concrete slurry surface image in a tunnel; edge feature fusion processing under related multi-scale features is carried out; carrying out edge curve region extraction and filling processing on the slurry edge binary image, and calculating and obtaining slurry surface centroid coordinates; feeding back and obtaining a laser Doppler speed measurement signal related to the flowing of the concrete slurry; carrying out adaptive windowing processing on the laser Doppler velocity measurement signal under related signal-to-noise ratio threshold judgment; and frequency interpolation correction processing under asynchronous sampling is carried out on the noise-reduced laser Doppler velocity measurement signal.

A method comprises: obtaining data from a radar, wherein the data comprise CD velocity data and CS velocity data, wherein the CD velocity data comprise RF velocity data and non-aliased velocity data, and wherein the CS velocity data are aliased and spatially correspond to regions with the RF velocity data; determining a boundary between the RF velocity data and the non-aliased velocity data in an initial CD map; replacing the RF velocity data with the CS velocity data in the initial CD map to obtain a modified CD map; and performing a velocity recovery on at least some of the CS velocity data along the boundary to obtain a dealiased map.

This application discloses a method and device for determining a spacecraft's orbit based on one-way Doppler, relating to the field of aerospace technology. The method comprises: establishing a first partial derivative model of the observation station's receiving frequency with respect to the target spacecraft's position based on a preset integration period and the one-way Doppler velocity equation, and establishing a second partial derivative model of the receiving frequency with respect to the target spacecraft's transmitting frequency based on the one-way Doppler velocity equation; solving the first and second partial derivative models to obtain the target spacecraft's position information and transmitting frequency; correcting the target spacecraft's position information and transmitting frequency based on random errors and systematic errors to obtain target position information and target transmitting frequency; and determining the target spacecraft's orbit based on the target position information and target transmitting frequency. This application solves the problem in related technologies of being unable to determine the orbit of distant spacecraft using two-way Doppler.

A method of processing reference signals at an apparatus includes: obtaining, at the apparatus, a reference signal (RS) configuration corresponding to a set of pilots to be transmitted on a set of resource elements in at least one RS repetition of an allocated RS; and selectively processing, at the apparatus, only a subset of the set of resource elements, to process fewer than all resource elements of the set of resource elements, based on at least one Doppler / velocity RS measurement consideration corresponding to at least one of a Doppler RS measurement or a velocity RS measurement.