51 results about "Velocity measurement" patented technology

This invention proposes a deep-sea multi-source fusion global navigation method based on time delay backtracking compensation, comprising the following steps: decomposing the actual state of the submersible into a nominal state and an error state; using the output of the inertial measurement unit to perform high-frequency integration extrapolation on the nominal state to obtain the predicted value of the nominal state; and recursively deriving the prediction error covariance matrix; acquiring the velocity measurement of the Doppler log, calculating the velocity measurement residual according to its working mode and introducing ocean current compensation; performing Kalman update to correct the nominal state to obtain the locally compensated nominal state; establishing a historical state buffer; when receiving an acoustic position measurement with a timestamp, calculating its time delay and retrieving the corresponding historical state; performing Kalman update to obtain the corrected historical state; and re-integrating and recursively deriving to the current time to obtain the current nominal state, which serves as the final global pose estimate of the submersible. This method can enable the submersible to maintain high-precision and high-stability navigation in complex deep-sea environments.

This invention provides a full-link detection device and method for laser interferometric velocimetry systems, relating to the field of transient photoelectric testing technology. The detection device includes a pulse injection module, a signal transmission and conversion module, and a signal acquisition and analysis module. The pulse injection module includes a nanosecond pulse laser and a coupler. The coupler is connected in series between the output end of the fiber laser and the first port of the circulator. The nanosecond pulse laser, after being coupled by the coupler, is transmitted along the entire system link and converted into an electrical signal by a photodetector. The data acquisition unit acquires the signal, and the analysis unit analyzes the characteristics of the electrical signal to achieve full-link status detection. This invention can identify and locate fiber optic path breaks, determine the working status of the fiber optic probe, and predict the intensity of the interference signal in the formal experiment. Even after the system is fully solidified before the experiment, it can still monitor the entire link status in real time, effectively improving the operational reliability and efficiency of the laser interferometric velocimetry system.

The utility model relates to flow velocity measurement technical field discloses a kind of granule conveying flow velocity measuring devices, including pipeline, the top of pipeline is equipped with observation platform, the top of observation platform is equipped with measuring mechanism, the bottom of observation platform is equipped with vibration mechanism, and the vibration mechanism includes motor, the drive end of motor is fixedly connected with rotating plate, the other end of rotating plate is rotatably connected with follower plate, the other end of follower plate is rotatably connected with linkage disc, the bottom of observation platform is fixedly connected with two limit posts, spring is equipped outside two limit posts, the outside of limit post is slidably connected with connecting disc. In the utility model, start motor, drive rotating plate to rotate, make follower plate rotate, and then let linkage disc slide on limit post, limit post moves up and down by spring to drive connecting disc to move up and down, connecting disc drives fixed column to move up and down by cylinder, and hammering vibration pipeline.

The application discloses a kind of pseudo-random code control's multi-parameter composite modulation short-range detector high-precision ranging velocity measurement method, comprising: echo signal and local oscillator mixing, obtain the intermediate frequency signal containing Doppler signal and difference frequency signal by low-pass filter, filter out high-frequency component;The input signal is converted into complex signal first after FFT, determine the refinement interval, then utilize spectrum refinement algorithm to accurately measure difference frequency signal frequency, calculate target distance by difference frequency frequency;Difference frequency signal is under-sampled to extract Doppler frequency, and the frequency of Doppler signal is measured by FFT, and the target speed is calculated by Doppler frequency.The application is from the establishment of composite system difference frequency signal model, using CZT conversion and time domain under-sampling technique to process difference frequency signal, finally extract difference frequency and Doppler signal frequency.

This invention discloses a transfer alignment method and device based on a left-invariant error model of Lie groups, belonging to the field of inertial navigation systems. The method first establishes a left-invariant error state model between the master and sub-inertial navigation systems based on Lie group theory; secondly, it constructs attitude and velocity error differential equations that simultaneously consider the effects of lever arm effects and installation error angles; then, it selects attitude and velocity measurements defined by the Lie group and establishes corresponding measurement equations; finally, it designs an unscented Kalman filter for the nonlinear state equations and measurement equations to jointly estimate parameters such as misalignment angle, velocity error, lever arm vector, installation error angle, and inertial navigation zero bias. The transfer alignment method proposed in this invention not only fully considers the actual lever arm errors between the master and sub-inertial navigation systems, improving the completeness of system error modeling, but also uses the local navigation coordinate system as the reference coordinate system, which is closer to actual engineering needs and has good versatility and engineering application prospects.

Embodiments of the present application disclose a method and device for establishing an ultra-shallow velocity model, electronic equipment and a storage medium. The method comprises: obtaining micro-logging data of a target area, wherein the micro-logging data comprises at least one measuring point and a corresponding velocity value of each measuring point, and the velocity value is obtained by measuring the velocity at the corresponding measuring point; for each analysis direction in at least one preset analysis direction, analyzing the micro-logging data in the analysis direction to obtain a function parameter, and determining a variogram corresponding to the analysis direction according to the function parameter; performing interpolation processing on the micro-logging data according to the variogram corresponding to each analysis direction, to obtain an interpolation result, and establishing an ultra-shallow velocity model of the target area according to the interpolation result. The technical scheme of the embodiments of the present application can be used to establish an accurate ultra-shallow velocity model.

Distinct lines of illumination produced by first and second lasers, angularly separated by a selectable angle between 1 and 15 degrees, are swept across a field of view using a scanning mirror, such that an object is sequentially illuminated with a known time delay determined by the angular separation and the mirror's movement. Reflections from the object are detected by corresponding detectors, and data from these events are processed to generate positional information for each illumination. By analyzing the change in object position between the captured data and factoring in a controlled time delay, a velocity measurement of the object is calculated.

This invention relates to a self-supervised 3D particle tracking and velocity measurement method, comprising the following steps: S1, acquiring a continuous temporal sequence of 3D source particle sets and 3D target particle sets, and performing feature encoding to obtain the feature matrix of the corresponding particle sets; S2, inputting the feature matrices of the source particle sets and target particle sets into a DFCT, and outputting the aligned cross-frame features; S3, constructing a transmission cost matrix between particles, establishing a dense soft correspondence between particles in two frames, and outputting the initial flow field estimation result and matching confidence; S4, constructing a composite self-supervised loss function, and iteratively optimizing the model parameters by minimizing the composite self-supervised loss function; S5, refining the initial flow field estimation result, and outputting the final 3D fluid velocity field. The beneficial effects of this invention are: solving the problems of algorithm dependence on large-scale high-quality labeled data, low efficiency in extracting semantic features from complex flow field point clouds, and matching ambiguity in high-displacement, high-density scenarios.

This application discloses a method and apparatus for measuring the velocity of micro- and nano-scale flowing targets, belonging to the fields of computer vision and fluid experimental measurement. The method includes: reading video containing micro- and nano-scale flowing targets frame by frame to generate multiple initial images; adaptively overlapping and slicing each initial image frame using a sliding window with a preset overlap rate to obtain a slice to be detected; performing parallel small target detection on each slice as a detection box to obtain a detection result group containing detection box information of micro- and nano-scale flowing targets; performing cross-slice fusion deduplication on the detection result group to obtain a deduplication result; based on the deduplication result, using a dual-threshold cascaded multi-target tracking algorithm to maintain the trajectory of micro- and nano-scale flowing targets, obtaining a maintenance result; and based on the maintenance result, using an inter-frame proximity matching algorithm to calculate the instantaneous velocity of each micro- and nano-scale flowing target. This application improves the detection accuracy, tracking stability, and velocity calculation reliability of micro- and nano-scale flowing targets.

This invention discloses a method, measuring device, and storage medium for measuring the speed of an object conveyed by a belt conveyor. The method includes: capturing images of a conveyor belt with laser lines using two cameras; matching the images captured by the two cameras to obtain the depth of the object containing the laser lines; calculating an evenly spaced object thickness distribution based on the obtained depth of the object containing the laser lines; obtaining the displacement of the object on the conveyor belt between two consecutive frames based on the evenly spaced object thickness distribution; and calculating the object's velocity based on the obtained displacement between the two consecutive frames. This invention obtains the evenly spaced object thickness distribution by interpolating the depth of the object containing the laser lines and accurately extracts the belt conveyor speed information using a cross-correlation algorithm, achieving direct measurement of the conveyor belt speed and ensuring high measurement accuracy.

This invention discloses an integrated ranging and velocity measurement method based on single-photon lidar, belonging to the field of high-precision laser detection technology. The method includes: obtaining the absolute detection time sequence of the photon response in the echo signal by referring to the absolute time of the zero point at the receiver; calculating the fundamental frequency f' of the echo signal and obtaining the pulse period t of the echo signal. r '=1 / f'; based on t r 'With the pulse period t of the transmitted signal r The Doppler equation is used to obtain an estimate of the target's radial velocity, calculate the relative detection time after motion compensation, and obtain an initial estimate of the initial photon flight time. Substituting these values ​​into the maximum likelihood estimation function, gradient optimization is performed to obtain its local optimum, thus achieving integrated measurement of the target's range and radial velocity. This invention enables the simultaneous acquisition of range and radial velocity in the same physical process.

Different illumination lines, generated by a first and a second laser separated by a selectable angle between 1 and 15 degrees, are swept across a field of view using a scanning mirror. This is done in such a way that an object is illuminated successively with a known time delay, determined by the angular separation and the mirror movement. Reflections from the object are detected by corresponding detectors, and the data from these events is processed to generate position information for each illumination. By analyzing the change in the object's position between the captured data points and incorporating a controlled time delay, a velocity measurement of the object is calculated.

This invention relates to a high-precision ultrasonic flow velocity measurement method and apparatus for viscous fluids, belonging to the field of fluid velocity measurement technology. The method involves transmitting and receiving signals to the fluid via an ultrasonic transducer, dynamically adjusting the gain and threshold using an adaptive signal conditioning module to generate stable trigger pulses, extracting multiple timestamps in parallel using a multi-event timing arbitration mechanism, and outputting the precise time of flight through arbitration logic. The line-average velocity is calculated based on the time difference between downstream and upstream flows, and combined with online sound velocity calibration and flow profile calibration, the surface-average velocity is output. This invention effectively overcomes the challenges of signal attenuation, waveform distortion, and dynamic changes in sound velocity in viscous fluids, achieving high-precision, adaptive, and robust flow velocity measurement, suitable for industrial process control.

A sensorless velocity measurement and positioning method and system for a linear motor in a suspended electromagnetic propulsion system is disclosed. The positioning method includes: observing unmodeled disturbances in a coordinate system using a designed disturbance observer to obtain the observed disturbance values ​​in the coordinate system; converting the observed disturbance values ​​in the coordinate system into a coordinate system and inputting them into an improved adaptive superspiral sliding mode back EMF observer to obtain the back EMF signal in the coordinate system, which is then input into a third-order orthogonal normalized phase-locked loop to obtain the position and velocity of the superconducting permanent magnet synchronous linear motor; and designing an extended state observer to input the position and velocity of the superconducting permanent magnet synchronous linear motor obtained from the third-order orthogonal normalized phase-locked loop into the extended state observer to obtain the optimized position of the superconducting permanent magnet synchronous linear motor. This invention can operate effectively in a linear motor of a suspended electromagnetic propulsion system and has good sensorless control performance.

The application belongs to the technical field of river surface flow velocity measurement, and discloses a method for predicting water flow surface flow velocity based on improved RAFT optical flow. Firstly, in the feature extraction stage, the feature descriptor information output by the SuperPoint network is fused, the representation ability of key features is strengthened, the reliability of feature matching is improved, and problems such as ambiguous optical flow estimation results are solved. Secondly, after correlation calculation, an evaluation module is introduced, the evaluation mode is used to calculate a matching quality evaluation index according to a 4D correlation body and a context feature map, and whether to enable a moving window function is judged according to the size of the evaluation index and a preset threshold value, so that the 4D correlation body is kept or updated. By introducing the moving window function, the problem of false features caused by optical flow discontinuity and noise in the water flow scene is solved, and the evaluation mechanism is constructed to dynamically decide the enabling time of the moving window function, so that the balance between the estimation accuracy and efficiency of the optical flow is realized.

This invention claims protection for a mixed-frequency time-difference amplification flow measurement method based on an improved ultrasonic time-difference method, belonging to the field of ultrasonic fluid velocity measurement technology. Addressing the problem of insufficient time-difference resolution in low-frequency ultrasonic flow measurement, this invention constructs a flow measurement architecture that deeply coordinates fiber optic sensing and heterodyne mixing: 1) An interferometric fiber optic sensor is used to acquire upstream and downstream ultrasonic signals, whose high signal-to-noise ratio and phase fidelity provide a distortion-free signal basis for subsequent time-difference amplification; 2) The two signals are digitally mixed with a reference signal and low-pass filtered. Utilizing the complete phase information retained by the fiber optic sensor, the microsecond-level original time difference is losslessly converted into a significantly amplified apparent time difference on the difference frequency signal; 3) The apparent time difference is extracted by cross-correlation and then the amplification factor is used to inversely deduce the actual propagation time difference; 4) The flow velocity and flow rate are calculated. In this invention, fiber optic sensing ensures the measurability and phase accuracy of weak low-frequency signals, while heterodyne mixing breaks through the traditional time-domain resolution limit. The two complement each other and work synergistically to significantly improve the accuracy and stability of flow measurement under complex river conditions.

This application relates to a flow measurement method, apparatus, computer equipment, storage medium, and computer program product. The method includes: when the error of the flow measurement result exceeds the allowable error range, adjusting the flow measurement pipeline to a first state where it is filled with liquid and the liquid is stationary; performing zero-point calibration on the flow measurement parameters based on the first state to obtain zero-point calibration parameters, so that the flow velocity measurement result obtained based on the zero-point calibration parameters in the first state is zero; adjusting the flow pipeline to a second state where it is filled with liquid and the liquid is flowing, and obtaining the instantaneous flow velocity measurement result in the second state; obtaining the full-scale coefficient in the flow measurement parameters, and obtaining a corrected full-scale coefficient based on the instantaneous flow velocity measurement result and the cumulative flow of the liquid during the sampling period; and measuring the flow rate of the liquid in the pipeline based on the corrected full-scale coefficient and the zero-point calibration parameters to obtain the measurement result. This method can achieve accurate measurement of the flow rate of fluid in a pipeline.

This invention discloses an online flow field estimation path planning method based on Bayesian inference, aiming to solve the problem of efficient detection and estimation of unknown flow fields by mobile robots. The method first discretizes the two-dimensional flow field region into a grid and constructs a probabilistic roadmap. In each planning round, a weighted maximum a posteriori (MAP) estimation problem is constructed based on the residuals of velocity measurements and fluid equations to solve for the flow field state and calculate the posterior accuracy matrix. Candidate paths are generated through bundle search and then prospectively expanded using subsequent information gain. After mapping path nodes to a set of proposed measurements, a joint prediction covariance matrix is ​​calculated. Based on a task weight matrix dynamically weighted according to velocity magnitude, a task-weighted posterior uncertainty reduction score is calculated for the candidate paths. The path with the highest score is selected for execution, and new measurements are collected. This process is repeated until a preset termination condition is met. This method integrates physical constraints and prospective search, guiding priority exploration of high-velocity regions and significantly improving the efficiency of online robot perception.

This invention discloses a single-shot shock wave velocity measurement system and method with timing calibration capability. The single-shot shock wave velocity measurement system includes a target chamber, a probe laser generation module, a timing calibration target, an interferometer, a streak camera, a focusing lens, a timing laser introduction module, and multiple main laser generation modules. During the timing calibration of the single-shot shock wave velocity measurement system, a customized timing calibration target reflects the main laser signal and the probe laser signal along the same optical path. A focusing lens is used to improve the signal-to-noise ratio. Simultaneously, a dedicated timing laser transmission component introduces the timing laser signal into the slit of the streak camera. This allows for the simultaneous acquisition of the main laser signal, the probe laser signal, and the timing laser signal in a single-shot measurement, achieving in-situ precise timing calibration for a velocity measuring instrument corresponding to any reflective surface.

This invention relates to a velocity measurement device based on the transient electromagnetic induction transparency effect. It utilizes two probe beams and two coupling beams to excite atoms in an atomic antenna to the Rydberg state. The probe beams are modulated into pulsed lasers to obtain the transient electromagnetic induction transparency signal of the Rydberg atoms. A first radio frequency signal source radiates electromagnetic waves to illuminate the target object; the reflected electromagnetic waves and the local oscillator electromagnetic waves radiated by a second radio frequency signal source simultaneously act on the Rydberg atoms at near-resonance. The velocity of the target object is measured by quantum precision measurement of the difference frequency signal generated by the interference of the two electromagnetic waves. Compared to traditional Rydberg atomic antennas, this invention's velocity measurement device based on the transient electromagnetic induction transparency effect can achieve velocity measurement of moving targets based on ultra-wideband, miniaturized quantum detection, thus expanding the functionality of Rydberg atomic antennas.

This invention provides a mobile platform for ice-crossing flow, thickness, and depth measurement, belonging to the field of hydrological measurement technology. An angle controller is installed on the trolley, and the ice thickness and depth measurement transducers and the flow velocity measurement transducers are respectively mounted on a lifting device, the bottom of which is equipped with a heating device. The lifting device containing the ice thickness and depth measurement transducers is directly mounted on the trolley, while the lifting device containing the flow velocity measurement transducers is mounted on the angle controller. This invention supports continuous multi-point rapid measurement, is suitable for large-scale ice surface water surveying and data acquisition, and effectively improves operational efficiency.

This invention relates to the field of water flow velocity measurement technology, and particularly to a method and system for dynamic state estimation of electronic buoys in water flow velocity measurement. The method employs BeiDou dual-frequency RTK positioning technology to obtain the observation position of the electronic buoy; it uses the universal transverse Mercator projection method to convert the longitude and latitude of the reference point into east and north distance coordinates, which serve as the origin of the electronic buoy observation coordinate system; it then converts the subsequently acquired electronic buoy observation position into east and north distance information, and performs difference calculations with the origin of the electronic buoy observation coordinate system to obtain the east and north distance offsets of the electronic buoy, which are used as measurement information; a dynamic state estimation model for the electronic buoy is constructed; and the measurement information is used as input parameters for a UKF filtering algorithm to perform real-time estimation of the electronic buoy's motion state. This invention directly processes the nonlinear characteristics of electronic buoy motion and water flow disturbances through a nonlinear Kalman filtering algorithm, significantly improving the accuracy and stability of state estimations such as velocity and heading angle.

The application discloses a water surface flow velocity detection method based on deep learning optical flow estimation, and belongs to the motion estimation task in the computer vision technical field. The method comprises the following steps: constructing an optical flow estimation network of water surface flow velocity, constructing an optical flow dataset for water surface flow velocity estimation, training an optical flow estimation network model of water surface flow velocity, and testing and using the optical flow estimation network model of water surface flow velocity. The application fully utilizes the advantages of the deep learning optical flow estimation model in the motion estimation field, uses a multi-scale fusion feature extraction network, calculates the multi-scale correlation between adjacent frames by using patch convolution, introduces a KPA attention mechanism, designs a multi-scale attention fusion optimization network, and the average velocity measurement error is only 0.056 m / s. The water surface flow velocity detection without tracer is realized, and the recognition precision of the model in the interference of uneven illumination and complex background environment is improved.

This invention discloses a Doppler frequency shift velocimetry system based on metasurface non-conjugate vortex beam interferometry. It primarily addresses the technical problems of existing velocimetry systems, such as system complexity, difficulty in integration, inability to simultaneously measure multiple motion parameters, and limited application in objects undergoing complex motion. The system includes a laser generation module, a first beam-splitting module, a metasurface structure, a second beam-splitting module, a reflection module, a third beam-splitting module, and a detection module. The metasurface structure is used to generate a non-conjugate vortex beam by adjusting its thickness and rotation angle. This invention utilizes a micrometer-sized metasurface structure to generate the required non-conjugate vortex beam, solving the problems of system complexity and integration difficulties in existing velocimetry systems, while simultaneously enabling the simultaneous measurement of multiple motion parameters of a target object undergoing complex motion.

A portable vertical multilayer ultrasonic flow measurement device includes a main measuring unit, at least two sets of ultrasonic transducer groups, at least two auxiliary measuring components, a first signal transmission component, a second signal transmission component, a first protective component, a second protective component, and a fixing component. Each ultrasonic transducer group includes a first ultrasonic transducer and a second ultrasonic transducer. The auxiliary measuring components are arranged parallel to each other. The first and second ultrasonic transducers are arranged on the same outer wall of the auxiliary measuring components along the flow direction of the fluid to be measured. The first signal transmission component connects the first ultrasonic transducers and the main measuring unit. The second signal transmission component connects all the second ultrasonic transducers and the main measuring unit. The first protective component is located on all the auxiliary measuring components and houses all the first ultrasonic transducers and the first signal transmission component. The second protective component is located on the auxiliary measuring components and houses all the second ultrasonic transducers and the second signal transmission component. The fixing component connects each auxiliary measuring component. This application improves the accuracy of flow velocity measurement.

The present application relates to the technical field of measurement, and particularly to a method for measuring speed with a gravitational field as a reference system, which can measure the speed of a substance without an external physical reference system. A reference object having a direct force interaction with the substance is an absolute reference system, such as light or electromagnetic waves propagating in a gravitational field or a substance, which has a direct force interaction with the field or the substance. Relative to the light, the gravitational field and the substance are absolute reference systems of the light. Because of the existence of the absolute reference system, when the substance has a relative speed relative to the field, the speed of the substance itself can be measured by the optical path (the optical path refers to the propagation path length of light or electromagnetic waves) of the field, and this process is the speed measurement with the gravitational field as a reference system.

This invention relates to the technical field of gas microflow velocity measurement, and proposes a method, system, and apparatus for gas microflow velocity measurement based on liquid surface tension. The method includes the following steps: controlling the injection of liquid B into a container, and then controlling the droplet addition of immiscible liquid A onto the surface of liquid B in the container; a positioning rod connects liquid A and liquid B; a wind-measuring plate floats on liquid A; under gas flow, the wind-measuring plate moves, causing liquid A to deform on liquid B; images are acquired to obtain the morphological parameters of liquid A under wind blowing; the ellipse eccentricity is calculated based on the morphological parameters of liquid A; a gas velocity calculation formula is constructed; the flow velocity of the measured gas is obtained and output based on the ellipse eccentricity and the gas velocity calculation formula; this invention requires only two immiscible liquids, a positioning rod, and a wind-measuring plate, reducing equipment costs; and achieves optical non-contact measurement by acquiring the morphological parameters of liquid A through image acquisition, exhibiting higher sensitivity and stability.

The application discloses a TDM-MIMO radar moving target detection method based on signal timing design. The application designs signal receiving and transmitting timing, that is, in a scanning period, a certain virtual channel continuously transmits and receives multiple pulses, and the rest of virtual channels only transmit and receive two pulses; pulse accumulation is realized by transmitting and receiving multiple pulses through a certain channel, two pulses are received and transmitted through the rest of channels to shorten the scanning period, and the problems of small non-blurring velocity range and poor detection real-time performance of the TDM-MIMO radar when detecting a moving target are solved. The application estimates the radial distance and radial velocity of a moving target based on the channel signals of continuously transmitting and receiving pulses, compensates the interference phase introduced by the Doppler frequency caused by movement according to the radial velocity estimation value of the target, realizes velocity-azimuth decoupling, and finally estimates the azimuth angle of the target by using a DBF algorithm. The application can consider the non-blurring velocity measurement range and the detection real-time performance, and realizes real-time detection of a moving target.