485 results about "Velocity measurement" patented technology

The invention discloses a pan-tilt-free dynamic compensation water flow velocity measurement system used in a vibration environment. The pan-tilt-free dynamic compensation water flow velocity measurement system comprises a multi-source sensor module, a dynamic motion compensation module, a self-adaptive Kalman filter bank and a data credibility evaluation module, the multi-source sensor module is used for collecting platform attitude information, water flow original speed and platform height. The dynamic motion compensation module comprises an attitude solution sub-module and an error calculation sub-module and is used for realizing flow velocity dynamic compensation under the condition of no holder structure; the adaptive Kalman filter bank comprises an angular velocity filter and a flow velocity filter, the angular velocity filter dynamically adjusts filtering parameters according to the angular motion intensity of the platform, and the flow velocity filter dynamically switches processing strategies according to the effectiveness of a water flow signal measured by the radar; and the data credibility evaluation module is used for carrying out stability judgment based on a sliding window variance-trend joint detection algorithm. According to the invention, attitude calculation and motion compensation are fused, and accurate measurement of the water flow velocity of the holder-free platform in a vibration environment is realized.

The invention discloses an intelligent control and detection system for precision coating uniformity, and relates to the technical field of non-contact thickness measurement, the system comprises a spectrum confocal chromatography detection module, a non-contact multi-wavelength full-breadth detection module, an optical flow field dynamic measurement module and the like, a data processing unit is combined with a model to generate an evaluation model, and the evaluation model is used for evaluating the coating uniformity. The system has the advantages that multi-layer coating structure data are obtained in a full-breadth mode through a linear array sensor of the spectrum confocal chromatography detection module, a slurry full-breadth flow velocity vector field is analyzed in combination with the optical flow field dynamic measurement module, and the flow velocity measurement accuracy is improved. And the data processing unit fuses the multi-modal data to generate an evaluation model, and the regulation and control strategy generation module outputs an instruction containing edge air pressure regulation, so that accurate control over coating uniformity is achieved, damage to a base material is avoided, material waste and manual debugging time consumption are reduced, and the production efficiency and the product yield are remarkably improved.

The invention relates to the technical field of underground engineering groove wall stability physical simulation, and discloses a model test device and method for stratum excavation and grouting reinforcement, and the model test device comprises a grooving construction module, a grouting support module and a dynamic monitoring module. The device adopts a pressing plate method to simulate a grooving excavation process, so that the device conforms to an actual excavation working condition from top to bottom; a servo motor drives a power lead screw to drive a model groove to move downwards, so that a free face is formed in a sand layer, and the actual excavation working condition is simulated; a water tank for storing fresh slurry is pressurized by using an air compressor, so that the slurry overflows from the hollow model groove section, and the permeation and invasion process of the slurry is simulated; and a water and soil pressure gauge and a matched acquisition device are arranged in the sand layer, and a soil displacement field is obtained by utilizing a particle image velocity measurement system, so that the visualization of the whole process of excavation-grouting-invasion is realized. It is ensured that simulation results are highly matched with actual working conditions, and accuracy and reliability are improved.

The invention discloses a method for measuring the flow velocity of fluid in a pipeline based on fluid medium parameter analysis, and relates to the technical field of fluid mechanics and fluid engineering. In order to solve the problems that in the prior art, flow velocity measurement data acquisition node arrangement and operation environment analysis of fluid in a pipeline are insufficient, the robustness of a measurement result is reduced, and the accuracy and reliability of flow velocity measurement are affected due to dependence on a single measurement model. Characteristic parameters such as fluid density and sound velocity are calculated and dynamically input into the flow velocity calculation model, real-time changes of the fluid parameters are comprehensively considered, the accuracy of the flow velocity measurement result is improved, the relation between the flow velocity and the sound wave propagation time difference is accurately established, the calculation result is compared with the flow velocity characteristic value and trend of historical data, and the accuracy of the flow velocity measurement result is improved. And the calculation precision of the flow velocity calculation model is evaluated based on the verification result, so that the adaptability, robustness and economy of the method are remarkably enhanced while the flow velocity measurement precision is improved.

The invention discloses a high-precision particle image velocity measurement method, and relates to the technical field of particle image velocity measurement, and the method specifically comprises the steps: 1, building a high-precision particle image measurement experiment platform, capturing continuous particle images through a laser-camera system with a synchronous time sequence, achieving the precise synchronization of laser pulses and camera exposure through an FPGA synchronous controller, and carrying out the measurement of the continuous particle images; the method comprises the following steps of: 1, acquiring a displacement image captured by a high-speed camera, and verifying synchronization precision, 2, processing the displacement image captured by the high-speed camera by using a technology combining a cross-correlation method and an optical flow method, and 3, introducing singular value decomposition in a PIV data processing process, decomposing flow field data, and separating main signals and noise. The sub-pixel-level precision of particle displacement measurement is remarkably improved, the signal-to-noise ratio of data is enhanced, and real-time error correction is achieved.

The invention is suitable for the technical field of hydrographic survey, and provides a river and channel water flow velocity measurement method based on video recognition and CFD simulation, and the method comprises the steps: S1, completing data collection and constructing a data set, S2, building a three-dimensional water flow model of a target river or channel, S3, generating a vertical flow velocity distribution model, S4, carrying out the image preprocessing of an obtained video stream, and S5, carrying out the calculation of a vertical flow velocity distribution model. S5, performing target detection on the preprocessed image and calculating an area of the flow velocity, S6, performing optical flow calculation on the extracted specific area and calculating the surface velocity, S7, establishing a distribution relationship between the surface velocity and the vertical velocity, and S8, calculating the real flow velocity of the river channel according to the surface velocity and the vertical velocity distribution. According to the method, the relation between the cross section vertical flow velocity obtained through simulation and the surface flow velocity obtained through calculation of the optical flow method is established, the real flow velocity is finally obtained, multi-source fusion of data is achieved, and the calculation accuracy and the flow velocity measurement precision are remarkably improved.

The invention discloses a speed measurement method based on single-frame multiple exposure, and belongs to the field of hypersonic velocity field measurement. The implementation method comprises the following steps: recording equal time interval change of molecular marking in a flow field along with movement of the flow field through single-frame multi-time exposure imaging of an image enhancement camera, and realizing continuous and rapid acquisition of speed information within a short time after single-time marking. The morphological position after the time interval is determined according to the molecular marker, and the velocity field with spatial resolution in the flow field is extracted by mapping the marker before and after displacement, so that the velocity measurement precision is improved. Compared with other two-dimensional velocity field acquisition methods based on femtosecond laser molecular marker tracing velocity measurement, the method provided by the invention does not need a complex focusing lens combination, can obtain spatial positions of molecular markers at different moments only through isochronous continuous triggering exposure of a camera, thereby obtaining velocity flow field displacement information. And corresponding acceleration information can be further deduced according to the obtained velocity field. The method is especially suitable for hypersonic velocity field measurement.

The invention discloses a channel flow velocity measurement error compensation method based on multi-source fusion, and the method comprises the following steps: S1, synchronously collecting flow velocity, position, attitude and environment data, including ADCP radial flow velocity, GNSS position / speed and IMU attitude angular velocity, through a multi-source sensor, aligning multi-source data based on a time synchronization mechanism, and achieving microsecond time synchronization based on PPS time service; according to the method, RTK high-precision positioning and ADCP bottom tracking data are integrated, the water surface elevation and the water bottom distance are inversed in real time, and the actual water depth and the riverbed erosion and deposition rate are dynamically calculated; edge calculation, motion compensation and external compass correction technologies are fused, the flow velocity and flow direction measurement precision is improved, and platform motion and attitude interference is eliminated; multi-source data local fusion processing and real-time generation of a flow velocity thermodynamic diagram and a water level change curve are realized, remote transmission and visualization are supported, and comprehensive and accurate hydrological data support is provided for maritime affair intelligent supervision, navigation safety early warning and digital channel construction.

The invention discloses a one-dimensional and two-dimensional simultaneous diagnosis shock wave velocity measurement system, and relates to the technical field of shock wave velocity diagnosis. The system comprises a targeting light receiving unit, a one-dimensional line imaging unit and a two-dimensional velocity field unit which are arranged on the same light path, the target shooting light receiving unit comprises a light receiving module and a target spot; the one-dimensional line imaging unit comprises a probe light injection module, a light splitting module, a first beam splitter, a first reflector, an interference module and a one-dimensional continuous velocity field measurement module; the two-dimensional velocity field unit comprises a two-dimensional dynamic velocity field diagnosis module; the two-dimensional dynamic velocity field diagnosis module comprises an integration branch and a compression coding branch. According to the system provided by the invention, in the process of performing one-dimensional and two-dimensional shock wave velocity field diagnosis, one-dimensional shock wave velocity evolution and two-dimensional velocity field non-uniformity evolution data can be simultaneously obtained in a single-shot experiment, the overall structure is compact, and a foundation is laid for shock wave velocity multi-dimensional diagnosis.

The invention discloses an acoustic Doppler flow velocity measurement method and system, and the method comprises the steps: generating an emission parameter combination adaptive to a current hydrological environment according to the depth characteristics and precision requirements of a target water area; original echo signals are collected based on the emission parameter combination, and a three-dimensional flow velocity vector of temperature compensation is output; inputting the three-dimensional flow velocity vector into the dynamic segmentation network to generate a layered flow velocity distribution model; calling a layered flow velocity distribution model, fusing fluxgate compass azimuth data to carry out flow direction compensation, triggering a deviation correction algorithm when equipment inclination exceeds a limit, and outputting absolute flow velocity distribution of pose calibration; and according to absolute flow velocity distribution and echo intensity dynamic range constraint, calculating an error interval of each depth unit, and outputting a final flow velocity profile with confidence identification. According to the embodiment of the invention, the environmental adaptability and data reliability of flow velocity measurement can be improved.

The invention provides a real-time calibration method and system for an inertial measurement unit, and a terminal, and the method comprises the steps: carrying out the first correction of an acceleration measurement value and an angular velocity measurement value which are output by a to-be-calibrated inertial measurement unit and are obtained in real time based on a temperature error compensation data table, and carrying out the second correction through employing a multi-sensor fusion filtering algorithm; on one hand, a temperature variable is introduced to carry out a multi-temperature zero offset test and a multi-temperature multi-axis rotation excitation test, a temperature error compensation data table is established, and the influence of temperature on the performance of the to-be-calibrated inertial measurement unit is fully considered; on the other hand, a multi-sensor fusion filtering algorithm is adopted, interference of vibration noise can be suppressed, the attitude calculation precision of the to-be-calibrated inertial measurement unit is improved, and therefore the calibration precision of the to-be-calibrated inertial measurement unit is guaranteed; the technical problems that an existing inertial measurement unit calibration method is low in calibration precision and poor in real-time performance are solved.

The invention discloses a nanosecond particle velocity measurement method based on orthogonal line polarization beam splitting, and belongs to the technical field of particle image velocity measurement. The method comprises the following steps: providing two linear polarization state orthogonal double-pulse lasers, and respectively outputting S polarization pulse light beams and P polarization pulse light beams; the four pulse light beams are combined through the double-path laser beam combining mirror set and output to the sheet light mirror set, and a plane illumination jet flow field with the thickness smaller than or equal to 1 mm is formed; scattered light is separated according to a polarization state by using a polarization beam-splitting cubic prism, and particle images under S polarization and P polarization are respectively captured by two double-exposure cameras which are orthogonally arranged; five kinds of time sequence control are triggered through a multi-channel synchronous controller; processing the view field deviation of the two cameras by adopting a block polynomial alignment method; and calculating a particle velocity field based on a particle tracking velocity measurement algorithm. According to the invention, the polarization debugging error is reduced, the homogeneity error after beam combination is obviously reduced, the coincidence degree of the four beams of planar light is improved, and a high-precision universal alignment scheme is provided for the multi-camera PTV technology.

The invention relates to a supersonic flow two-dimensional Mach number distribution field measurement system and method, on the basis of a femtosecond laser electron excitation mark speed measurement system, a diffractive optical element is combined to enable an output laser beam to be shaped into dot matrix light, and the combination means can be used for measuring the two-dimensional Mach number distribution field under the condition that the total energy of laser is not greatly lost. The FLEET technology is converted from single-point / linear velocity measurement to two-dimensional flow field velocity measurement. Secondly, a two-dimensional temperature field measuring device based on Rayleigh scattering forms two-dimensional sheet-shaped laser by using a sheet-shaped laser generating assembly, and two-dimensional calibration data measurement under known conditions is carried out by monitoring static pressure of a flow field and laser energy; and in combination with a formal test two-dimensional Rayleigh scattering result, supersonic flow two-dimensional temperature distribution analysis is realized. The two-dimensional flow field velocity measurement device, the two-dimensional temperature field measurement device and static pressure measurement are synchronously implemented by using the signal synchronous generation device to obtain same-time and same-frequency test data, so that supersonic flow two-dimensional Mach number distribution can be constructed through the data.

The invention relates to the field of particle image velocimetry (PIV), in particular to a multi-scale Res2RAFT particle image velocimetry method based on global attention mechanism optimization. The invention aims to solve the problem that an existing optical flow network is insufficient in prediction of a fine-grained displacement field in a complex flow field, especially in application in multi-scale vortex and turbulent flow fields. By designing an optical flow estimation structure with multi-scale feature extraction and global information interaction, Res2RAFT can more accurately capture fine flow features in a complex flow field, and the flow field prediction precision and adaptability in a PIV task are improved. According to the Res2RAFT particle image velocity measurement method provided by the invention, the defects of a traditional PIV method in processing an underwater complex flow field are overcome, high-resolution displacement field prediction of the flow field is realized through fine multi-scale feature extraction and a global attention mechanism, and the Res2RAFT particle image velocity measurement method has a wide application prospect.

The invention belongs to the technical field of tunnel engineering geophysical prospecting, and particularly relates to a full-wave-field tunnel advanced prospecting method based on rock physical constraint, which comprises the following steps of: constructing an initial geologic model, sampling on an upper interface of a layer section where a tunnel is located and carrying out longitudinal and transverse wave velocity measurement to obtain a longitudinal wave velocity Vp and a transverse wave velocity Vs; combining all sampled longitudinal wave velocities Vp and transverse wave velocities Vs, calculating longitudinal wave velocities and transverse wave velocities of a target layer section, obtaining elastic parameters of the target layer section, importing the obtained elastic parameters into an initial geologic model, obtaining a parameter inversion initial model, constructing a forward wave field and a simulated seismic record, and making a difference between an actual observation record and a simulation record, so as to obtain an initial geologic model; and conjugate gradient inversion is carried out. According to the method, all wave field information excited by the shield tunneling machine is fully utilized, and high-precision parameter inversion is carried out under rock physical constraints, so that more accurate tunnel front geological prediction can be provided, and a scientific basis is provided for safe and efficient construction of the shield tunneling machine.

The invention provides a river flow velocity intelligent monitoring method and system based on multi-scale optical tracking velocity measurement. A plurality of detectors with different characteristics are organically combined, and dynamic grid density adjustment based on flow velocity gradient is realized through adaptive grid adjustment; establishing a multi-dimensional track quality evaluation system through intelligent track evaluation; the real-time performance optimization realizes the performance optimization of multi-thread parallel processing, integrates an intelligent grid optical flow detection and dynamic density adjustment mechanism, and optimizes the detection precision and performance in real time according to the flow velocity gradient and the flow field complexity; a multi-track quality evaluation system is utilized, tracks are screened and fused from three dimensions of motion consistency, physical constraint and time stability, and the accuracy and reliability of data are remarkably improved. The method overcomes the problems that a traditional speed measurement method is complex in operation, limited in environment, insufficient in precision and the like, supports real-time processing, can be widely applied to the fields of water conservancy projects, environment monitoring, flood prevention early warning, scientific research and education and the like, and has remarkable advancement and practical value.

A comprehensive system designed for the predictive maintenance of railcar wheel bearings, integrating multiple sensor modalities. The system includes thermography for temperature mapping, vibration analysis via a three-axis accelerometer, rotational velocity measurement using a rate gyro, and optical spectrometry for lubricant analysis. Each modality contributes to a holistic understanding of bearing health, enhancing maintenance strategies, safety, and operational efficiency in rail transportation.

The invention relates to an experimental device and method for researching liquid drop dynamics and evaporation characteristics. The experimental device comprises a liquid drop generation system, a metal flat plate control system, a height adjusting system and a data acquisition system, the liquid drop generation system is used for generating liquid drops impacting the metal flat plate; the metal flat plate system is used for adjusting the inclination angle of a metal flat plate to heat the metal flat plate; the height adjusting system is used for adjusting the height from the liquid drop generating system to the metal flat plate, so that the liquid drops impact the metal flat plate at different speeds; the data acquisition system comprises a high-speed camera, an infrared camera, a particle image velocity measurement device, a light source and a computer, and is used for measuring the morphological change, velocity field and temperature field of liquid drops in the process of impacting the metal flat plate; the invention further provides an experimental method. According to the invention, the morphological evolution process of the liquid drops can be measured, and the dynamics and evaporation characteristics of the liquid drops when impacting metal plates with different inclination angles and surface types can be studied.

The invention provides a flow field velocity measurement device and velocity measurement method for a rotor channel of turbomachinery, and relates to the technical field of fluid mechanics, the flow field velocity measurement device comprises a laser suitable for generating first line laser; a tracer particle flow field is formed in the cartridge receiver, and a rotatable rotor is arranged in the tracer particle flow field; the transparent window is arranged on the window of the casing; the sheet light source forming assembly is suitable for reflecting the first line laser to the interior of the cartridge receiver and forming a plurality of sheet light sources capable of moving in the radial direction of the rotor; the camera assembly is suitable for shooting tracer particles in the tracer particle flow field through the transparent window based on a plurality of sheet light sources at different radial positions to obtain multiple frames of particle images corresponding to different radial positions; and the processor is suitable for obtaining the flow field speed of the rotor channel based on the multi-frame particle image.

The invention discloses a space-time image velocity measurement method and system based on multi-direction Gabor filtering, and the method comprises the steps: carrying out the filtering processing of a space-time image through Gabor filters in multiple directions, so as to enhance the texture features in multiple directions, carrying out the image quality evaluation of a Gabor filtering image in each direction, and obtaining the velocity measurement of the space-time image. The filtering direction with the best textural feature enhancement effect is screened out; a clustering point set with the highest comprehensive evaluation score is screened out through a two-layer evaluation screening mode of clustering quality evaluation and line segment quality evaluation, straight line fitting is carried out based on the clustering point set, an optimal flow velocity line can be obtained, and the river surface flow velocity is obtained through calculation; according to the method, a three-layer evaluation system composed of filtering direction evaluation, clustering quality evaluation and line segment quality evaluation is combined, a high-quality, correct and effective flow velocity line can be accurately extracted from a space-time image, and the accuracy and robustness of a flow velocity measurement result are greatly improved.

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 discloses a simulation lunar dust excitation speed measurement system and method under a vacuum plume action condition, and relates to the technical field of aerospace engineering, and the system comprises a vacuum chamber and thruster system, an image collection assembly, a synchronous control collection system, a pulse laser light path, a high-speed spotlight, and a simulation lunar surface. In the invention, two optical systems of particle image velocity measurement and particle tracking velocity measurement are integrated in the same experiment, and the 532nm optical filter and the light trapping sheet are configured to realize compatibility of optical requirements, so that the problems that lunar dust particles with different scales and velocities cannot be measured synchronously and the optical systems interfere with each other in the prior art are solved; according to the method, velocity field data of micron-sized high-speed small particles and millimeter-sized low-speed large particles can be synchronously obtained and directly correspond to each other, the measurement integrity and reliability are improved in combination with simulation environment and synchronous control, and accurate data support is provided for spacecraft lunar dust prevention design.

The invention discloses a hydrological flow and speed measurement method, which relates to the technical field of hydrological measurement and comprises the following steps: selecting a dynamic anchor point in a target speed measurement area, and carrying out anchor point hovering on an unmanned aerial vehicle according to the dynamic anchor point; the unmanned aerial vehicle collects surrounding images of the unmanned aerial vehicle to obtain obstacle data, and a motion route is generated in real time; the unmanned aerial vehicle performs video acquisition on the target velocity measurement area to generate a three-waveband water surface video, and analyzes the three-waveband water surface video to generate an initial velocity distribution diagram; the unmanned aerial vehicle collects riverbed data and water surface fluctuation data of the target flow measurement area, and according to the riverbed data, a riverbed terrain is obtained, and water depth data and a section average flow velocity are obtained; and constructing a three-dimensional water flow model, collecting a movement track of the buoy group and gyroscope data, correcting the three-dimensional water flow model, and outputting a hydrological flow and velocity measurement result. The method has the effects of improving the measurement precision of flow measurement and speed measurement and improving the flexibility and universality when facing a complex water area.

The application discloses an indoor water tank sediment starting speed measurement system and method, and aims at solving the technical problem of sensor disturbance to a flow field and influence on data accuracy in the prior art measurement method.The technical scheme core is that the non-contact measurement characteristics of the PIV technology are applied to the whole process from flow field construction to data acquisition.The device is mainly composed of an imaging unit, a laser illumination unit, a movable sliding frame, a water flow adjusting unit and a buffer plate.Optical measurement is performed through the imaging unit and the laser illumination unit, and physical sensors do not need to be arranged in the flow field, so that the interference of the measuring instrument on the water flow structure and the sediment starting process is fundamentally avoided.The integrated movable sliding frame integrates the sediment laying, particle throwing and measurement functions, and is convenient for quickly positioning a test area;in combination with the buffer plate and the water inlet and drainage adjusting unit, a gradually changing flow field from weak to strong can be accurately and stably simulated.

The invention discloses a background schlieren method flow field flow velocity measurement method based on pseudo-schlieren images. The method comprises the following steps: constructing a background schlieren experiment measurement system; obtaining a speckle plate image sequence without a flow field background; obtaining a background distortion image sequence; obtaining a pseudo schlieren image sequence; and obtaining the final flow velocity of the flow field to be measured. The method has the advantages that a background plate distortion image sequence under the action of a flow field is collected through a high-speed camera, and pseudo-schlieren transformation processing is carried out through an improved mixed gradient operator and a multi-scale feature fusion technology; and a flow velocity field is solved in combination with a PIV-optical flow fusion algorithm, and real-time processing is realized through GPU parallel computing. The method breaks through the limitation that the traditional PIV technology depends on tracer particles, has the advantages of non-contact, full-field measurement, high temporal-spatial resolution and the like, and is particularly suitable for compressible flow field and turbulent flow field measurement. Experiments show that the method can realize high-resolution and high-frame-rate image processing, the uncertainty of flow velocity measurement is less than 3.2%, and a new technical means is provided for complex flow field diagnosis.

An imaging system includes a sensor that measures a velocity of a moving object, a camera that is different from the sensor and images the object, and a processing circuit that controls the operations of the sensor and the camera, wherein the processing circuit causes the sensor to generate velocity information on the object and measurement timing information on the velocity by causing the sensor to measure the velocity of the object, generates control data, including imaging timing information on the camera, in accordance with (a) position information on the object or distance information on the object at a time of velocity measurement, (b) the velocity information, and (c) the measurement timing information, and causes the camera to output, in response to the control data, image data including image information on the object.

The invention relates to a centrifugal compressor PIV speed measurement and analysis method, device and equipment and a medium. The method comprises the following steps: acquiring flow field optical measurement data of the centrifugal compressor through a particle image velocity measurement technology; inputting optical measurement data of the flow field into a deep learning model, and extracting dynamic characteristics of the flow field through a characteristic extraction layer of the deep learning model; reconstructing the dynamic characteristics of the flow field into a three-dimensional flow field velocity vector field by using a velocity vector reconstruction layer in the deep learning model; and generating a velocity measurement analysis result based on the three-dimensional flow field velocity vector field. By adopting the method, the multi-scale dynamic characteristics in the complex three-dimensional rotating flow field of the centrifugal compressor can be effectively captured, high-precision three-dimensional velocity vector reconstruction is realized, and the spatial resolution and robustness of flow field measurement are improved.

The invention provides a three-dimensional stereoscopic particle image velocity measurement system. The three-dimensional stereoscopic particle image velocity measurement system comprises a light source assembly, a receiving camera, a special-shaped prism and a processing unit. The light source assembly is suitable for emitting sheet light to illuminate tracer particles in a flow field to be measured; a sensor of the receiving camera is configured into two parts which are respectively suitable for recording images of a first view field and a second view field in a to-be-measured flow field, the first view field and the second view field are inclined relative to a to-be-measured plane, the inclined directions are opposite to form an included angle, and the first view field and the second view field also have an overlapping region; the special-shaped prism is arranged between the to-be-measured flow field and the receiving camera, and is suitable for respectively guiding light rays of the first view field and the second view field to the receiving camera, and enabling the optical path lengths of the light rays of the first view field and the second view field to be equal; and the processing unit is suitable for receiving and storing the image from the receiving camera and processing the image to obtain velocity field data of the flow field to be measured.

The invention relates to a video-based flow measurement method and an intelligent flow measurement system. The method comprises the following steps: extracting a flow velocity analysis reference image from a recorded video; establishing an analysis point on the first flow velocity analysis reference image of the time sequence; determining a change vector of each analysis point according to other flow velocity analysis reference images of the time sequence; selecting an analysis area on the first flow velocity analysis reference image of the time sequence according to the length and the direction concentration ratio of the change vector; extracting an analysis image from the flow velocity analysis reference image corresponding to the analysis area, and performing feature extraction on the analysis image to obtain a flow velocity feature; and calculating the average moving speed of the flow velocity characteristics to obtain the flow measurement speed. According to the video-based flow measurement method and the intelligent flow measurement system disclosed by the invention, the grabbing area is determined based on local feature analysis, feature grabbing is performed in the grabbing area, and then the flow velocity is measured based on the grabbed features, so that the relatively accurate water flow velocity can be obtained.

The invention discloses a transfer alignment method and transfer alignment equipment based on a Lie group left invariant error model, and belongs to the field of inertial navigation systems. The method comprises the following steps: firstly, establishing a left invariant error state model between a master inertial navigation system and a slave inertial navigation system based on the Lie group theory; secondly, constructing an attitude and speed error differential equation considering the lever arm effect and the installation error angle influence at the same time, then selecting attitude and speed measurement defined under the Lie group, and establishing a corresponding measurement equation; and finally, designing an unscented Kalman filter according to the nonlinear state equation and the measurement equation, and carrying out joint estimation on parameters such as a misalignment angle, a speed error, a lever arm vector, an installation error angle and inertial navigation zero offset. The transfer alignment method provided by the invention not only fully considers the actual lever arm error between the main inertial navigation system and the sub inertial navigation system, improves the integrity of system error modeling, but also adopts the local navigation coordinate system as the reference coordinate system, is closer to the actual engineering requirements, and has good universality and engineering application prospects.