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102 results about "Linear measurement" patented technology

Method and device for identifying geometric error of numerical control (NC) machine tool based on modified 9-line method

A method and a device for identifying geometric errors of a numerical control (NC) machine tool based on a modified nine-line method. Motion errors between a plurality of rigid bodies of the NC machine tool is superimposed to construct a comprehensive error model based on multibody system kinematics theory and a topological structure of the NC machine tool. Optimization is performed based on the comprehensive error model and a preset fitness function to predict six optimal measurement positions. Six linear measurement trajectories are established respectively at the six optimal measurement positions. The six linear measurement trajectories are each parallel to one of an X-axis, a Y-axis, and a Z-axis. error terms for each of the six linear measurement trajectories are measured to establish a first equation set having six first equations. Geometric error simulation and identification for the NC machine tool are performed based on the first equation set.
Owner:GUANGDONG OCEAN UNIVERSITY

Method, system, medium and equipment for measuring diopter of micro lens of out-of-focus lens

The invention provides an out-of-focus lens microlens diopter measurement method, system, medium and device, and relates to the technical field of optical measurement, and the method comprises the steps: placing a to-be-measured out-of-focus lens on a rotary table; controlling a Z-axis motion guide rail to drive a line measurement sensor to move, and determining a path scanning zero point; the rotary table is controlled to rotate at a constant speed, and the X-axis movement guide rail and the Z-axis movement guide rail drive the line measurement sensor to move so as to obtain point cloud data of the upper surface of the to-be-measured out-of-focus lens; performing conversion, fitting and data extraction on the point cloud data to obtain a two-dimensional profile curve of each micro lens unit included in the to-be-measured defocus lens; and calculating the diopter of each micro-lens unit according to the two-dimensional profile curve of each micro-lens unit. According to the method, independent quantitative evaluation of the additional diopter of the microstructure is realized, and the defects that the macroscopic diopter and the microstructure diopter cannot be separated by a lensometer and the macroscopic diopter and the microstructure diopter are difficult to accurately disassemble in an existing non-contact technology are overcome.
Owner:TIANJIN UNIV

Self-supervised tomographic SAR reconstruction method based on orthogonal subspace decomposition

The invention discloses a self-supervised tomographic SAR (Synthetic Aperture Radar) reconstruction method based on orthogonal subspace decomposition. According to the method, a traditional single original space is reconstructed and expanded into a Range-Null-Raw triple space collaborative learning framework, an R2R and N2N principle-based self-supervised loss function is constructed by using an orthogonal subspace decomposition characteristic of a linear measurement operator, direct mapping learning from noise measurement data to a high-quality reconstruction result is realized, and the real-time performance of a real-time reconstruction system is greatly improved, so that the real-time performance of the real-time performance of the real-time performance of the real-time performance of the real-time performance of the real-time performance of the real-time performance is improved. Observable components are learned through Range space, unobservable components are learned through Null space, a cross constraint strategy of global consistency is ensured through Raw space, and the adaptability of the model to real measurement conditions is enhanced. The performance gap between simulation training and actual deployment in deep learning TomoSAR reconstruction is effectively solved, and a new solution is provided for reliable application of an unsupervised deep reconstruction network in a real TomoSAR imaging task.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

Insulation measuring rod

The utility model provides an insulation measuring rod which comprises an insulation rod, a measuring head and a measuring device, the measuring head is arranged on the head portion of the insulation rod, the measuring device is arranged inside the tail portion of the insulation rod, the head portion of the insulation rod is provided with a fixing ring, and the tail portion of the insulation rod is provided with a rotatable wire roller. A wire of the measuring device is wound on the wire roller and is connected with the measuring head through the fixing ring. The beneficial effects of the utility model lie in that the circular ring is arranged at the rod head as a fixed pulley, so that the measuring head can descend along with a lead at the rod head, and the whole device forms an L shape to measure more multi-angle measuring positions which are inconvenient for linear measurement, thereby solving the problem of measurement in a complex environment or an environment in which linear approach is difficult, and improving the measuring accuracy. The position and the angle of the measuring head can be flexibly adjusted, and the whole measuring device forms an L-shaped structure, so that the measuring device can adapt to more multi-angle measuring requirements, especially positions which are difficult to reach through a linear measuring method.
Owner:滨州绿能热电有限公司 +1

Dynamic temperature field real-time reconstruction method and system based on multi-source sound wave data

The invention discloses a dynamic temperature field real-time reconstruction method and system based on multi-source sound wave data, and relates to the technical field of fire monitoring and early warning, and the method comprises the steps: deploying a sound wave receiving and transmitting array in a target region, constructing a multi-source sound wave measurement network, and determining a signal track space; connecting a visual simulation platform, constructing a verification database and storing the verification database to a platform data center; developing a reconstruction unit in the visual simulation platform, and determining a reconstruction temperature field; and executing linear measurement and calculation based on acoustic trajectory points and interpolation compensation of a non-trajectory region by taking a preset distributed interval as a constraint. According to the invention, the technical problems that the measurement is easy to interfere and the internal temperature is difficult to accurately acquire in real time in the high-temperature and dynamically-changing complex environment in the traditional method are solved, and the technical effect of accurately acquiring the internal temperature field information in real time in a non-contact manner in the high-temperature and dynamically-changing complex environment is achieved.
Owner:ZHENGZHOU UNIVERSITY OF LIGHT INDUSTRY

A verticality detection device for building construction

The present invention discloses a verticality detection device for building construction, which relates to the technical field of detection equipment. The device comprises an automatic detection system, a locking mechanism, a cone and a cone line. The cone is suspended on the locking mechanism through the cone line. The automatic detection system comprises a monitoring device. The locking mechanism is perpendicular to the building surface to be measured. The monitoring device is used to emit detection light to the building surface to be measured and receive the light by a receiving device on the cone. The automatic detection system determines the verticality of the building surface to be measured based on the emission angle and the receiving angle of the detection light. By providing the locking mechanism and the monitoring device, the present invention eliminates the need for manual multi-point measurement using a tape measure, is simple to operate, and converts the existing multi-point measurement into linear measurement, further improving the measurement accuracy.
Owner:WUDI COUNTY HUIBIN CONSTR ENG CO LTD

Unmanned aerial vehicle impact interception method and impact unmanned aerial vehicle based on monocular vision

The present application relates to a kind of unmanned aerial vehicle impact interception methods based on monocular vision, the azimuth measurement information and angle measurement information of target unmanned aerial vehicle are calculated by target detection algorithm based on monocular vision;Azimuth measurement information and angle measurement information are used, through orthogonal projection matrix and algebraic transformation, non-linear measurement is converted into pseudo-linear form, then pseudo-linear adaptive Kalman filtering algorithm is carried out to estimate the position of target unmanned aerial vehicle, finally, unmanned aerial vehicle maneuvering strategy is used to control impact unmanned aerial vehicle to realize the impact interception of target unmanned aerial vehicle.The method of the present application is obviously improved in system noise robustness, target state estimation accuracy and pursuit efficiency.The present application also relates to impact unmanned aerial vehicle guided by the above impact interception method.
Owner:HEBEI UNIV OF SCI & TECH

Bearing inner ring raceway diameter measuring method

The invention relates to the technical field of bearing measurement, in particular to a method for measuring the diameter of a raceway of a bearing inner ring, which comprises the following steps of: selecting a standard steel ball, using simple measuring equipment, forming a simple geometric model according to design parameters of a bearing, and calculating the diameter of the raceway of the bearing inner ring through a trigonometric function relationship and a geometric relationship. In this way, direct measurement of the arc-shaped raceway is converted into linear measurement, and the linear measurement is converted into the diameter of the bearing inner ring raceway through the trigonometric function relation, so that the measurement error can be greatly reduced, the measurement result is more accurate, meanwhile, the measurement efficiency can be improved, and the cost is low.
Owner:LUOYANG LYC BEARING

Optimization method of coil parameters of eddy current sensor

The present invention belongs to the field of metrology and calibration technology, and specifically discloses a method for optimizing coil parameters of an eddy current sensor, including: determining coil materials and basic size parameters; generating sample data between coil parameters and performance; constructing a BP neural network model, training and fitting the nonlinear relationship between coil parameters and measurement performance; optimizing the BP neural network model and coil parameters using a particle swarm algorithm; and designing and manufacturing an eddy current sensor based on the optimization results. The present invention uses a BP neural network to model the nonlinear mapping relationship between coil parameters and sensor performance, and combines the global optimization capability of a PSO algorithm to achieve intelligent optimization of coil parameters; the sensor coil designed through optimization has good performance and can achieve high-precision linear measurement within a range of 2 to 15 mm.
Owner:THE 704TH RES INST OF CHINA STATE SHIPBUILDING CORP

IC board warping degree and curved surface groove detection method based on three-dimensional point cloud

The invention discloses an IC board warping degree and curved surface groove detection method based on a three-dimensional point cloud, and the method comprises the following steps: S1, collecting the point cloud data of the surface of an IC board through a three-dimensional imaging device, and carrying out the noise filtering, resampling and attitude normalization preprocessing; s2, nine key points distributed on the surface of the IC board are automatically extracted, a reference surface is generated through a curved surface fitting algorithm based on coordinates of the key points, and the height deviation value of each key point relative to the reference surface is calculated; according to the method, nine key points are selected on the surface of the IC Board, the global reference curved surface is generated by combining the curved surface fitting technology of the three-dimensional point cloud, and errors caused by local height anomaly or measurement noise are effectively avoided. Through the multi-dimensional analysis of the height difference between the central point and the edge point, the quantification of the warping degree is more comprehensive, the measurement result is more stable and reliable, and compared with a traditional single-point or linear measurement method, the method has higher precision and robustness.
Owner:SHENZHEN NANOVISION CORP

Non-linear measured value accurate mapping method and system based on slope dynamic wingspan

The invention discloses a nonlinear measurement value accurate mapping method and system based on a slope dynamic wingspan. The method comprises the following steps: establishing a plurality of data calibration points in one-to-one correspondence between a target domain and a measurement domain; defining calibration point intervals, and establishing a slope wingspan model corresponding to each calibration point interval; collecting a plurality of measurement domain data of the to-be-measured object; calculating through the slope wingspan model of the calibration point interval to which the data of each measurement domain belongs to obtain a corresponding target domain result group; re-integrating the target domain results in the target domain result group to reduce the number of the target domain results; selecting a median of the sorting of the integrated target domain results as a final mapping result; the method is simple and convenient in calculation process, high in mapping precision, high in real-time performance, low in manufacturing cost and easy to implement, and has wide application prospects in the fields of workpiece three-dimensional shape measurement based on the precision measurement technology, object dynamic property change monitoring, precision displacement measurement, trace gas measurement, trace mass weighing and the like.
Owner:CENT SOUTH UNIV

Micro extension spring inspection device

An inspection device for measuring micro spring tension. The inspection device includes a guideway and a linearly slidable plate slidably positioned within the guideway and having an elongated opening formed therethrough. The inspection device further includes a load cell fixed relative to the guideway and extending through the elongated opening of the linearly slidable plate. The micro spring is attached between a slide spring attachment fixed to the linearly slidable plate and a load cell spring attachment fixed to the load cell. Finally, the inspection device includes a linear measurement indicator shaft and one or more processors for outputting to a user interface or an external system a load associated with signals from the load cell and / or a distance associated with signals from the linear measurement indicator shaft.
Owner:HONEYWELL FEDERAL MANUFACTURING & TECHNOLOGIES LLC

Seamless range switching system and method for instrument current measurement

The invention discloses a seamless range switching system and a seamless range switching method for instrument current measurement. The seamless range switching system comprises a digital-to-analog converter, an error amplifier, a first driving circuit, a first current measurement circuit, a clamping circuit, a second driving circuit, a second current measurement circuit, two analog-to-digital converters and a field programmable gate array. The first current measuring circuit converts 10 [mu] A to 30 mA low current into a first voltage signal to form a negative feedback closed loop. When the first voltage signal reaches a Zener breakdown threshold value, the clamping circuit outputs a trigger signal to start the second driving circuit, so that the two driving circuits jointly provide a total current of 30mA to 500mA for the load; the two analog-to-digital converters perform synchronous sampling, and the field programmable gate array selects digital signal output which is in a linear measurement range and has an error not exceeding + / -0.05% of a full scale. No mechanical switch exists in the switching process, the current is uninterrupted, and wide-range high-precision continuous measurement is achieved.
Owner:JIANGSU UNIV OF TECH

Circuit breaker

The utility model discloses a circuit breaker. The service life evaluation unit is used for evaluating the residual electric operation service life of the circuit breaker according to current measurement data records of the current measurement unit; the current measuring unit comprises a first current measuring circuit and a second current measuring circuit which are arranged in parallel; the first current measurement circuit is a current measurement circuit based on an iron core current transformer, a current measurement value ICT of the first current measurement circuit is used as a current basis for circuit breaker protection action judgment, and when the ICT is in a linear measurement range of the iron core current transformer, the ICT is used as current measurement data for recording; the second current measurement circuit is a current measurement circuit based on a PCB Rogowski coil transformer, and the current measurement value IRC of the second current measurement circuit is recorded as current current measurement data when the ICT is out of the linear measurement range of the iron core current transformer. Compared with the prior art, the device can accurately measure the fault current, and further provides an accurate basis for the evaluation of the service life of electric operation.
Owner:CHANGSHU SWITCHGEAR MFG CO LTD (FORMER CHANGSHU SWITCHGEAR PLANT)

Segmental beam prefabrication linear measurement method and system based on mixed mark positioning

The invention discloses a segmental beam prefabrication linear measurement method and system based on mixed mark positioning. The method comprises the steps that circular diagonal coding marks are arranged at control points of a fixed end mold and the top of a segmental beam; the circular diagonal coding mark adopts two characteristics of a white positioning circle and a diagonal mark; acquiring a plurality of images comprising all circular diagonal coded marks, and identifying and acquiring the center coordinates of each coded mark in each image by adopting an image processing method; matching marks with the same coded value in different images, and performing initial calculation on camera external parameters of each image and three-dimensional world coordinates of a control point on the top surface of a segmental beam based on known three-dimensional world coordinates of a control point of a fixed end mode; and global joint optimization is carried out on the camera external parameters of all the images and the three-dimensional world coordinates of the control points at the top of the segmental beam to obtain the three-dimensional world coordinates of the control points of the segmental beam. The problems of large manual measurement error, low efficiency and the like can be solved, and automation of linear measurement of the precast beam field is realized.
Owner:CENT SOUTH UNIV

A k-shortest-path-based edge computing network service function chain embedding method

The application discloses an edge computing network service function chain embedding method based on K shortest path, and aims at a distributed service function chain embedding problem under time delay constraint. In the case of meeting the end-to-end time delay constraint, a service function embedding algorithm based on K shortest path algorithm is designed to minimize the deployment cost. The application firstly proposes a service function embedding problem modeling method based on a weighted layered graph, and converts the service function chain embedding problem into a minimum cost path problem under time delay constraint in the weighted layered graph. Secondly, a service function chain embedding mechanism under time delay constraint is designed based on the weighted layered graph and K-linear measurement aggregation algorithm. Compared with the prior art, the application has better high performance and operability, and has practical significance for complex network applications in edge computing networks.
Owner:NANJING TECH UNIV

An equivalent source sound field positioning method and system based on sparse sound intensity measurement

ActiveCN122262664BEquivalent source methodSound sources
The present application belongs to the field of sound field reconstruction and sound source identification technology, and discloses an equivalent source sound field positioning method and system based on sparse sound intensity measurement, which acquires the complex sound pressure and complex particle velocity at the measurement point on the holographic surface through a vector sensor array, and calculates the measured sound intensity vector; constructs a sound intensity transfer matrix based on the equivalent source method, establishes a linear measurement equation between the measured sound intensity vector and the equivalent source intensity vector; by using the spatial sparsity of the equivalent source intensity, the solving of the equivalent source intensity vector is converted into an L1 norm sparse optimization problem, and a convex optimization algorithm is used to solve it to obtain the optimal equivalent source intensity vector; based on the optimal equivalent source intensity vector, the acoustic quantity at any point in the target sound field is reconstructed by combining the free field Green function. The present application uses the active component of the sound intensity vector to suppress non-related noise, improves the ill-conditioned inversion by combining the compressive sensing theory, and can realize high robustness and high precision sound source positioning and sound field reconstruction without reference microphones.
Owner:DONGHAI LAB

Linear measurement device and method for liquid refractive index in visible wavelength band optical fiber spr

The application provides a visible light band optical fiber SPR liquid refractive index linear measurement device and method, the device comprises a broadband light source, a first lens and a second lens, a polarizer, a third lens and a fourth lens, a pinhole, a fifth lens, an optical fiber SPR, a sixth lens, a diffraction grating, a concave mirror, a linear array CCD and a data processing unit; the data processing unit is used for extracting the resonance wavelength corresponding to the normalized light intensity minimum value from the wavelength-intensity spectrum curve, and calculating the refractive index of the liquid medium to be measured according to the linear relationship between the refractive index and the resonance wavelength which is calibrated in advance. The device is not only intuitive in optical path debugging and easy to operate, but also has a rigorous theoretical model and high measurement precision, and is very suitable for rapid and accurate refractive index screening and analysis of a large number of low-concentration liquid samples, and has wide application prospect and industrial value.
Owner:NORTH CHINA UNIVERSITY OF TECHNOLOGY

Apparatus and method for measuruing bore hole depth

PendingUS20260071862A1SurveyMechanical depth measurementsAgpaitic rockYoung's modulus
The invention relates to an apparatus for measuring a depth of a bore hole. The apparatus includes an elongated strip including linear measurement markings along at least a portion of a length of the strip. A weight is provided at an end of the strip and the strip is comprised of material that has an elastic (Young's) modulus of greater than 0.5 and less than 2.0 GPa. Embodiments of the invention are adapted to quickly and effectively measure the depth of a bore hole or a depth to any major obstructions such as loose rocks that may have fallen into the bore hole.
Owner:AQUIRIAN TECHNOLOGY PTY LTD

Testing device for smoke detectors

Smoke detector test bench (1) (test device), preferably in the form of an optical bench, for the functional testing of a smoke detector, in particular a linear smoke detector based on the transmitted light principle, in particular for conformity testing in accordance with the requirements of and / or in accordance with DIN EN 54-12, in particular for functional testing by evaluating the attenuation or attenuation change of an optical beam (2), in particular for determining the response value (trigger limit value), in particular wherein the smoke detector to be tested responds to attenuation and / or attenuation change of an optical beam (2) and has at least one transmitter (3), at least one receiver (4) and optionally at least one reflector (5) or at least one transmitter-receiver arrangement (6) and at least one reflector (5), wherein the smoke detector test bench (1) comprises: - a first test specimen holder (7) for holding and / or receiving a receiver (4) or a transmitter-receiver arrangement (6) of a smoke detector to be tested, - a second test holder (8), in particular arranged opposite the first test holder, for holding and / or receiving a transmitter (3) or a reflector (5) of the smoke detector, wherein an optical, in particular linear, measuring section (2) is formed and / or is present between the first test specimen holder and the second test specimen holder (8), preferably wherein the first test specimen holder (7) and the second test specimen holder (8) are arranged and / or are to be arranged such that in the operating and / or test state of the smoke detector test stand (1) the receiver (4) or the transmitter-receiver arrangement (6) of the smoke detector to be tested, held and / or received by the first test specimen holder (7), on the one hand, and the transmitter (3) or reflector (5) held and / or received by the second test specimen holder (8), on the other hand, are positioned and / or aligned at least substantially at the same height and / or (horizontally) aligned; the smoke detector test bench (1) also features: - a positioning device (9) for the particularly selective and / or preferably automated and / or motorized insertion and / or removal of several test filters (10) from a plurality of test filters (10) provided and / or make available, in particular with the positioning device (9), into the beam path and / or out of the beam path of an optical beam (2) emanating from the transmitter (3) or the transmitter-receiver arrangement (6) and optionally reflected by a reflector (5) to generate an attenuation or a change in the attenuation of the optical beam (2), in particular wherein the positioning device (9) is designed • for the selective and / or preferably automated and / or motorized insertion and / or removal of a plurality of test filters (10), in particular both a single test filter (10) and a plurality of test filters (10), into or out of the beam path, wherein several test filters (10) inserted into the beam path have different distances to the first test specimen holder (7) and / or to the second test specimen holder (8), preferably different distances to the first test specimen holder (7) and to the second test specimen holder (8), and / or • for the selective and / or preferably automated and / or motorized insertion and / or removal of several test filters (10) from a plurality of test filters (10) into the beam path and / or out of the beam path, wherein the test filters (10) inserted into the beam path are arranged linearly in succession in the beam path in the direction of the optical beam (2); in particular wherein the positioning device (9) has a plurality of test filter holders (11) arranged linearly in the direction of the optical beam, wherein each test filter holder (11) is designed to hold and insert and / or remove at least one, preferably only one, test filter (10) into or out of the beam path and / or wherein each test filter holder (11) can be positioned independently of the other test filter holder(s) (11) within the beam path and / or wherein the test filter holders have a different distance to at least one test specimen holder (7, 8), in particular to both test specimen holders (7, 8), and / or in particular wherein the positioning device (9) is designed for the independent insertion and / or removal of several test filters (10) from a plurality of test filters (10) into or out of the beam path, preferably wherein each test filter (10) can always be inserted into the optical beam (2) at a test filter-specific position specified for the respective test filter (10) with a test filter-specific distance to at least one test specimen holder (7, 8), in particular to both test specimen holders (7, 8), preferably to the transmitter (3) or the transmitter-receiver arrangement (6) or to the receiver (4).
Owner:VDS SCHADENVERHUETUNG GMBH

A measuring method of a low-loss proportional amplification fluxgate current sensor

The application discloses a kind of low-loss proportional amplification fluxgate current sensor measurement methods, it is related to current measurement technical field, including, obtaining the observation set of synchronous demodulation by phase-locked;Based on the scheduling optimization function of prediction set construction, apply soft opening constraint, amplitude stability constraint, phase consistency constraint and saturation depth constraint, output corresponding control variable;According to control variable setting excitation signal parameter and executing excitation drive and compensation injection, extract the harmonic amplitude-phase response of current cycle in demodulation window position;Harmonic amplitude-phase response is converted into linear measurement output of current cycle, while updating observation set.The application implements proportional closed-loop conversion in I / Q rectangular coordinates, combines amplitude error and phase error into compensation current update amount, and combines calibration proportionality coefficient and output amplitude limiting, so that closed-loop converges amplitude-phase deviation in linear interval quickly, improves compensation current stability and response speed and reduces energy consumption.
Owner:SHANGHAI DEJIE ELECTRONIC TECH CO LTD

Measurement method of fluxgate current sensor with low loss and scale amplification

The invention discloses a measurement method of a fluxgate current sensor with low loss and scale amplification, which relates to the technical field of current measurement and comprises the following steps of: acquiring an observed quantity set subjected to phase locking synchronous demodulation; constructing a scheduling optimization function based on the pre-measurement set, applying a soft opening constraint, an amplitude stability constraint, a phase consistency constraint and a saturation depth constraint, and outputting a corresponding control variable; excitation signal parameters are set according to the control variables, excitation driving and compensation injection are executed, and harmonic amplitude phase response of the current period is extracted in the position of the demodulation window; and converting the harmonic amplitude-phase response into linear measurement output of the current period, and updating the observed quantity set at the same time. Proportional closed-loop conversion is implemented in I / Q rectangular coordinates, amplitude errors and phase errors are synthesized into compensation current updating quantity, and a calibration proportionality coefficient and output amplitude limiting are combined, so that a closed loop quickly converges amplitude-phase deviation in a linear interval, the stability and response speed of compensation current are improved, and energy consumption is reduced.
Owner:SHANGHAI DEJIE ELECTRONIC TECH CO LTD

Robust visual servo control method and verification system based on interference estimation

The invention discloses a robust visual servo control method and verification system based on interference estimation. The method comprises the following steps: acquiring an environment RGB image and depth information; constructing a state transition equation and a pseudo-linear measurement equation, and performing joint estimation on the target position and speed by adopting a Kalman filter; according to the estimated target space position, establishing a geometric mapping relation between a rotary table coordinate system and a target coordinate system, and calculating an attitude angle required by the rotary table; and designing a time-varying disturbance observer, estimating unmodeled dynamics and external disturbance of the system in real time, performing feed-forward compensation based on a disturbance estimation value, and generating an anti-disturbance control instruction in combination with an expected attitude angle. The system is applied to the servo control method and comprises the two-degree-of-freedom rotary table, the depth camera, the target, the connecting firmware, the laser director, the balancing weight and the ground station. According to the invention, the precision of servo control can be improved. The method can be widely applied to the field of sensing control.
Owner:SUN YAT SEN UNIVERSITY SHENZHEN +1

Radar maneuvering target tracking algorithm based on RKF multiple models

The invention belongs to the technical field of radar maneuvering target tracking, and particularly relates to an interactive multi-model radar maneuvering target tracking algorithm based on random Kalman filter (RKF), which is suitable for effective tracking of a maneuvering target under the condition of polar / spherical coordinate measurement. According to the method, a plurality of RKF filters with different variances are introduced under an interactive multimode framework, so that the coverage of the motion state of a maneuvering target with multiple unknown motion modes is realized, and meanwhile, non-linear measurement conversion of depolarization and decorrelation is realized based on a predicted value under the filtering framework; finally, a radar maneuvering target tracking algorithm (IMM-RKF-DUCM) based on multiple RKF models is provided. Compared with the traditional IMM-REKF, IMM-DUCM and single-model RKF-DUCM, the method can maintain high stability and high precision in an unknown or rapidly changing maneuvering scene, significantly reduces the probability of failure, and is a radar target tracking algorithm with higher robustness and better tracking performance.
Owner:UNIV OF ELECTRONICS SCI & TECH OF CHINA

A polarization-entangled photon voltage sensor

The present invention relates to a polarization-entangled photon voltage sensor, comprising a type II self-parametric down-conversion polarization-entangled photon source, a high-potential sensing optical path, and a ground-potential measurement optical path. The sensing optical path comprises a BZN ceramic, an electro-optical crystal, a quarter-wave plate, and a white screen. The measurement optical path comprises a collimating beam expander and a radial polarization grating. The type II self-parametric down-conversion polarization-entangled photon source outputs two polarization-entangled photons. One photon enters the high-potential sensing optical path and sequentially passes through the BZN ceramic, the electro-optical crystal, and the quarter-wave plate before annihilating on the white screen. The other photon enters the ground-potential measurement optical path, passes through the collimating beam expander to form spatial light, and then passes through a radial polarization grating for polarization analysis. The electro-optical phase delay is converted into a synchronous translation of a fixed light spot. By using an image sensor to position the light spot, direct linear measurement of the electro-optical phase delay can be achieved, thereby obtaining a voltage to be measured. The present invention overcomes the problems of optical power dependence, nonlinear measurement, and the inherent half-wave voltage of the crystal that limits the measurement range and sensitivity of Pockels effect optical voltage sensors.
Owner:FUZHOU UNIV

Indirect, Accurate, and Linear Fluid Level and Moisture Concentration Measurement System and Method Thereof

A system to provide non-invasive, indirect, continuous, and linear measurement of fluid levels and aggregate soil moisture concentrations. A multilayer device implements a coplanar capacitor capable of measuring fluid levels outside the wall of the vessel containing the fluid. Additionally, the system measures fluid levels and soil moisture concentrations outside the wall of a sealed probe placed in the water or soil. The structure is shielded from surrounding electrical interference, can be manufactured in a cost-effective manner, and be tailored for different physical applications. The invention also includes an electronic circuit for measuring fluid levels and moisture concentrations that represents a robust design in terms of accuracy, noise suppression, calibration, and temperature stability.
Owner:BOWMAN ROBERT J

Novel magnetron sputtering target material thickness detection equipment

The utility model belongs to the technical field of semiconductor coating equipment, and particularly relates to novel magnetron sputtering target material thickness detection equipment which comprises a main chamber, a back plate, a left baffle and a right baffle are arranged in the main chamber, a track transmission part, a guide rail and an infrared distance measuring sensor are arranged in a sputtering equipment process cavity, and the track transmission part drives the guide rail to move. The infrared distance measuring sensor moves along the guide rail to linearly measure the distance from the infrared distance measuring sensor to the surface of the target material, and then the residual thickness of the target material is calculated, so that the real-time monitoring of the thickness of the target material is realized, and the replacement time of the target material is accurately determined; compared with the prior art, the measuring precision and the production efficiency of the machine are improved.
Owner:ZHEJIANG XINDONG TECH CO LTD

A three-dimensional target electromagnetic property perception method based on a reconfigurable intelligent surface

The application relates to the technical field of electromagnetic imaging, in particular to a three-dimensional target electromagnetic property perception method based on a reconfigurable intelligent surface, which comprises the following steps: configuring parameters of an electromagnetic imaging system, generating RIS unit scattering coefficients based on mutual coherence optimization by adopting an MCBB algorithm; configuring the scattering coefficients on the RIS, scattering and reconstructing electromagnetic waves generated by a transmitting antenna; linearly correlating contrast parameters of a measurement target with received scattering field data by adopting a linear measurement model; and finally, inverting the target electromagnetic property by utilizing mt_cs. The application realizes high-precision inversion of the target electromagnetic property in the RIS-assisted imaging framework by optimizing and designing the super-surface reflection coefficient and constructing a measurement matrix with multi-dimensional low cross-correlation characteristics.
Owner:NANJING UNIV OF POSTS & TELECOMM