24 results about "Absolute measurement" patented technology

The invention discloses an absolute measurement method and device for the density of molten salt and solution, and belongs to the field of molten salt physical property tests.The measurement method comprises the steps that 1, a cone and cylinder composite heavy hammer is adopted to measure the density of the molten salt or solution; 2) arranging two measuring positions on the cylinder section of the heavy punch, taking the section between the two measuring positions as a middle measuring section, the length of the middle measuring section is equal to the distance between the two measuring positions, the diameter of the middle measuring section is equal to the diameter of the cylinder of the heavy punch, and measuring at the two positions in sequence; (3) the density of the fused salt or the solution is determined by the volume of the middle measuring section of the heavy hammer and the buoyancy borne by the middle measuring section, so that the density of the fused salt and the solution is deduced; according to the method, a long-distance microscope system is adopted to directly measure the thermal expansion of the heavy hammer at high temperature, calibration by a standard substance is not needed any more, when the method is adopted to measure the density of the fused salt and the solution, the volume of the heavy hammer does not need to be calibrated, additional force caused by surface tension is completely removed, the measurement process is greatly simplified, and the measurement precision is improved.

The invention belongs to the technical field of precise optical measurement, particularly relates to a method and a device for measuring the curvature radius of a nano-precision aspherical lens, and provides the following scheme aiming at the problems that the curvature is calculated indirectly through rise in the existing process of measuring the curvature radius of the aspherical lens, the process is easily interfered by errors, and the measurement accuracy is influenced. The method comprises the following steps: S1, clamping a to-be-measured lens, and adjusting an optical axis; s2, moving a to-be-measured lens to a focus of a fixed measurement light path, and carrying out concurrent alignment; s3, a Gaussian measurement light beam is emitted and received; s4, planning a virtual spherical surface, and performing virtual sphere center space scanning; according to the method, error amplification is fundamentally avoided through a direct measurement principle of virtual sphere center scanning and wavefront matching, so that nano-precision and absolute measurement of curvature radiuses at any point of various aspheric lenses is realized, a whole-situation surface shape can be further inverted through multi-point and multi-parameter measurement, and the measurement precision is improved.

The invention relates to a three-dimensional detection system and method for the inner wall of a cylindrical workpiece. According to the three-dimensional detection system for the inner wall of the cylindrical workpiece, precise annular calibration scales are circumferentially arranged on the inner wall of a standard circular tube jig; the line laser sensor is mounted in a manner of forming a fixed inclination angle relative to the rotation axis of the standard circular tube jig, and the scanning range of the line laser sensor can simultaneously cover the inner wall of a to-be-measured workpiece placed in the jig and the scale area of the inner wall of the jig; the rotation driving device is used for driving the standard circular tube jig and a to-be-detected workpiece arranged in the standard circular tube jig to rotate around the rotation axis together; according to the three-dimensional detection method for the inner wall of the cylindrical workpiece, XY-axis physical adjustment is replaced with scales as a calibration mode, distortion correction of a laser image is completed through data compensation, scanning data of the workpiece and a standard circular tube jig are subjected to synchronous registration in a three-dimensional space, absolute measurement is converted into relative measurement, and therefore system errors are eliminated automatically.

The application belongs to the technical field of electric digital data processing, and discloses a fault test method of a Flexray bus, which comprises the following steps: in a non-data transmission state of a bus network, injecting, by an excitation node, a sub-threshold electric excitation pulse which appears as noise to a communication controller; measuring, by the excitation node itself, a local echo of the pulse to obtain a real-time probe fingerprint, and meanwhile, measuring, by a listening node, a far-end response signal of the pulse; finally, performing normalization processing on the far-end response signal by using the real-time probe fingerprint, and comparing the normalized far-end response signal with a reference feature to determine whether the bus has a potential fault, wherein the application establishes a dynamic self-calibration measurement reference, solves the diagnostic confusion problem caused by state fluctuation of an excitation source itself, changes the nature of fault test from relative comparison to quasi-absolute measurement which can resist signal source drift, and improves the confidence and reliability of online diagnosis of unattended transaction equipment.

The invention relates to a VR equipment observability enhancement method based on relative-absolute state estimation, a medium and application, and the method comprises the steps: defining a coupled head display state and a controller state, and building a continuous time dynamic model based on an IMU; constructing an overall measurement model based on an absolute measurement model of the head-mounted display and a relative measurement model between the head-mounted display and the controller; a relative-absolute state estimation problem is constructed and solved, and state estimation of the head-mounted display and the controller is obtained through joint optimization; based on relative-absolute state estimation, VR equipment observability enhancement is realized by utilizing kinematics constraints among equipment provided by a relative measurement model; when the method is applied to the condition that the head-mounted display is lack of visual absolute measurement, the accelerometer deviation is also observed through the state correlation with the controller; media are implemented based on the method. According to the method, the stability and availability of head-mounted display absolute pose estimation are maintained in a time period lacking visual absolute reference, and the long-term precision and stability of inertial navigation are fundamentally improved.

The invention discloses a laser tracking measurement device and method based on double optical combs, and the device comprises a rough measurement laser light source, a double optical comb light source, an indication light source, a tracking control module, an angle measurement module, and a signal collection and processing module. When the light beam is aligned with the center of a measured target, the double-optical-comb combined distance measuring light path is combined to output a unified measuring light beam to be incident on the measured target; a measured target is reflected back to the double-optical-comb combined ranging light path along the original path to form a measured signal, the signal acquisition and processing module processes the measured signal, the absolute distance measurement of the measured target is realized by fusing coarse and fine ranging, and a space coordinate measurement result of the measured target is calculated by combining an angle value. Therefore, space coordinate absolute measurement with a large non-fuzzy range, high precision and high speed measurement can be realized.

A measuring instrument includes a movable portion configured to rotate in an arc motion about a pivot portion, and an electronic position encoder configured to measure an absolute relative position between a detector portion and a scale portion, one of which forms part of the movable portion. A maximum movement range of the movable encoder portion and a maximum absolute measurement range are each less than 360 degrees. Based at least in part on detector signals that are received from the detector portion, an offset value is determined that corresponds to a radial offset (e.g., of the scale portion or the detector portion). The determined offset value is utilized to correct one or more values that are utilized to determine a relative position between the detector portion and the scale portion (e.g., such as a value corresponding to a spatial step or other spatial value of the scale portion).

The invention discloses an FP sensor demodulation system and method based on a double-optical-comb spectrum technology, and belongs to the field of double-optical-comb precision measurement. In order to overcome the defects in the prior art, the FP sensor demodulation system based on the double-optical-comb spectrum technology is provided, a broadband optical frequency comb light source is used for detecting an FP sensor, a high-speed and high-resolution double-optical-comb spectrum detection method is combined, and high-resolution mapping of an FP sensor interference spectrum in a radio frequency domain is achieved. And absolute measurement and dynamic tracking of the cavity length of the FP sensor are realized by using a high-precision frequency domain demodulation algorithm, so that the limitation of the traditional FP demodulation technology in the aspects of demodulation resolution, demodulation speed and system stability is broken through, and a new technical scheme is provided for multiplexing sensing application of the high-precision and quasi-distributed FP sensor.

The invention discloses a single-energy neutron fluence rate absolute measurement device based on a 6LiF telescope system, and belongs to the technical field of neutron detection, the single-energy neutron fluence rate absolute measurement device comprises a cylinder, a collimation diaphragm is arranged in the cylinder, the collimation diaphragm comprises a first center hole and a second center hole, the first center hole and the second center hole are coaxially arranged and have the same diameter, and the first center hole is communicated with the second center hole. A first center hole is formed in one end of the cylinder, a composite layered neutron conversion body is mounted at the first center hole and comprises an aluminum substrate, a 6LiF active layer is evaporated on the upper surface of the aluminum substrate, a passivation ion implantation planar silicon detector is arranged behind a second center hole and is provided with an SMA connector, and a rear cover is arranged at the other end of the cylinder. The center of the rear cover is provided with a BNC female base leading-out signal line. Based on the structural design of the invention, the absolute measurement of the single-energy neutron fluence rate in the energy region from 1 keV to 100 keV can be realized. The method can be used for establishing the reference research of the single-energy neutron fluence rate in the energy region from 1 keV to 100 keV, and the traceability and accuracy of the measurement result of the single-energy neutron fluence rate are ensured.

The invention provides a device for measuring the flow velocity in a natural circulation process, and the device comprises a circulating water system which is connected with a reactor to form a complete closed loop, and is used for simulating a natural circulation loop of a passive containment cooling system of a nuclear power station; the tachymeter system is used for measuring the flow velocity of the fluid in the circulating water system to obtain high-resolution three-dimensional velocity measurement; and the data acquisition system is connected with the tachymeter system and is used for converting the physical signals into fluid mechanics parameters. According to the invention, the measurement precision is high, the spatial resolution can reach micron to millimeter magnitude, the time resolution can reach microsecond magnitude, and the instantaneous characteristics of low flow velocity and high turbulence in natural circulation can be accurately captured. Laser Doppler velocity measurement is an absolute measurement method based on light wave frequency, the result does not need field calibration, and the reliability is high.

Analytical device and analytical process, set up for internal referencing which is independent from the kind of optical response of a sample. The device comprises a light source directed to a sample location, a photon counting detector set up to receive light emanating from the sample location and to generate photon counts, an integrator coupled to the detector and set up to receive photon counts from the detector and to integrate the photon counts over an integration time to generate integrated measurement signals, and coupled to the integrator an analogue-to-digital converter set up to receive the integrated measurement signals and to generate digital measurement signals for each of the integrated measurement signals and to deliver the digital measurement signals to a control unit, which is set up for deconvolution of the digital measurement signals in order to determine correction functions, wherein the control unit is set up to convert separately determined digital measurement signals which are determined for samples in dependence on the correction functions.

This invention discloses an absolute planar two-dimensional time-grating displacement sensor and measurement method using photoelectric combined measurement, belonging to the field of precision measurement and sensing technology. It includes a sensor body, a signal acquisition module, a hardware circuit module, and a digital signal processing module. The signal acquisition module is used to acquire displacement signals generated by electric field measurement and positioning signals generated by optical field measurement. The hardware circuit module is used to process the optical field positioning signal and the electric field displacement signal. The digital signal processing module is used to obtain the positioning value and the precisely measured displacement values ​​in the X and Y directions based on the signal processed by the hardware circuit module. The combination of these two values ​​outputs the absolute displacement value. This invention employs photoelectric combined measurement, using time-division image positioning and electric field displacement measurement. The combination of these two methods enables planar two-dimensional absolute displacement measurement, reducing random errors, improving measurement accuracy, and achieving high-precision absolute measurement over a large range.

The invention provides a spherical two-position absolute surface shape measurement method, and belongs to the field of high-precision interference measurement. According to the spherical surface two-position absolute surface shape measurement method, on the basis of the existing spherical surface three-time interference method measurement, spherical surface two-position absolute measurement in a confocal position rotation step is removed, and a wave surface returned by a to-be-measured spherical surface at a cat eye position is a wave surface obtained after a spherical wave of a standard spherical mirror is rotated by 180 degrees relative to an optical axis. And after the result of interference measurement of the two positions is rewritten by using the parity about theta in the polynomial formula of the circular function, the absolute surface shape of the spherical surface to be measured is further solved. Compared with a spherical surface cubic interference method in the prior art, the spherical surface two-position absolute surface shape measuring method has the following beneficial effects that (1) the operation is simple and convenient; (2) the measurement efficiency is higher; and (3) maladjustment errors caused by rotation measurement of a confocal position in the prior art are not introduced, and the precision of absolute measurement is further improved.

This invention discloses a method based on 6 The monoenergetic neutron fluence absolute measurement device for the LiF telescope system, belonging to the field of neutron detection technology, includes a cylindrical body. A collimating aperture is installed inside the cylinder, comprising a first central aperture and a second central aperture. The first and second central apertures are coaxially aligned and have the same diameter. A composite layered neutron converter is installed at the first central aperture. The composite layered neutron converter includes an aluminum substrate, and the upper surface of the aluminum substrate is coated with a... 6 A passivated ion-implanted planar silicon detector is positioned behind the second central hole of the LiF active layer. This detector is equipped with an SMA connector. A rear cover is located at the other end of the casing, with a BNC female connector at its center leading out signal lines. Based on this structural design, absolute measurement of monoenergetic neutron fluence in the energy range of 1 keV to 100 keV can be achieved. This contributes to establishing a benchmark study of monoenergetic neutron fluence in the 1 keV to 100 keV energy range, ensuring the traceability and accuracy of monoenergetic neutron fluence measurement results.

The application discloses a master-slave positioning method and system based on a confidence factor from a UAV preferably distributed EKF, and relates to the technical field of UAV positioning. i , if the master UAV is invalid, calculating the confidence of each slave UAV i , selecting the slave UAV with the highest confidence, upgrading it to a temporary master UAV; constructing a state equation and a measurement equation of the slave UAV i; calculating an absolute measurement gain matrix and a relative measurement gain matrix respectively; calculating a predicted value of relative measurement information and updating a state variable and an error covariance matrix; and completing positioning. The application realizes normal operation of the system in the case of invalidation of the master UAV, and effectively controls the increase of positioning error caused by invalidation of the master UAV.

The invention relates to an absolute temperature measuring device and method based on an isotope absorption spectral line, and belongs to the technical field of temperature measurement. The measuring device comprises a light source, a micro air chamber and a light signal receiving piece which are sequentially arranged on a transmission light path, a mixture containing gas A and gas B is hermetically packaged in the miniature gas chamber, and the gas A and the gas B are different isotope gases of the same substance. The light absorption intensity of different isotope gases of the same substance is obtained, absolute temperature measurement is achieved (the absolute temperature is calculated according to the light absorption intensity ratio of the different isotope gases of the same substance), the problem that an existing measuring device cannot achieve absolute measurement in the true sense is solved, and the measurement accuracy is improved. The measurement principle of the invention abandons the traditional electrical temperature measurement principle, realizes absolute temperature measurement of'one-time calibration and lifelong maintenance-free 'directly based on molecular spectroscopy constants, and has the advantages of electromagnetic interference resistance, fast response, good long-term stability and the like.

The invention relates to the field of internal and external diameter measurement, in particular to an internal and external diameter measuring instrument which comprises a base plate, a supporting piece, a positioning piece and a measuring piece, the supporting piece is detachably connected to the base plate, the supporting piece is used for supporting a workpiece, the base plate is provided with a separation line, and the separation line penetrates through the circle center of the base plate; the positioning pieces and the measuring pieces are arranged on the two sides of the separation line respectively, the positioning pieces are detachably connected to the base plate, the multiple positioning pieces are arranged around the axis of the base plate at intervals, the positioning pieces are used for placing and positioning workpieces, the measuring pieces are detachably connected to the base plate, and the measuring pieces are used for measuring the workpieces. The measuring piece is used for abutting against the inner wall or the outer wall of the workpiece. Through comparative measurement, a complex degree process and human interpretation errors in absolute measurement are avoided, and a measurement result is simplified into direct comparison with a tolerance range, so that standardization of a detection process and visualization of an interpretation result are realized, the detection efficiency is greatly improved, and the skill threshold of an operator is reduced.

The invention discloses a method for measuring the content of 227Ac in a 225Ac solution, and belongs to the technical field of nuclide analysis. Comprising the following steps: providing a 227Ac diluent solution with known activity concentration; equally dividing a to-be-detected 225Ac solution into two equal parts, adding a quantitative 227Ac diluent solution into one part as a labeled sample, and taking the other part as a non-labeled sample; respectively measuring the isotope ratios of 227Ac / 225Ac in the two samples; based on the principle of isotope dilution mass spectrometry, by comparing two ratios and combining the sampling amount, the diluent solution adding amount and the activity concentration of the diluent solution, a material balance relation is constructed, and the activity concentration of 227Ac and 225Ac in the to-be-detected solution is obtained. According to the invention, absolute measurement is realized through the principles of high-sensitivity measurement, micro-sampling and an isotope dilution method of a mass spectrometer; and by combining a material balance equation, the method for rapidly and accurately measuring the content of 227Ac in the 225Ac solution in a trace amount can be realized.

The invention belongs to the technical field of tunnel engineering and structural health monitoring, and discloses a tunnel structural body displacement deformation measuring system and method based on image recognition, a reference target, a multi-stage transmission target and a monitoring section target are arranged between a second lining stable area and an excavation face in a tunnel, and corresponding image displacement sensors are configured. The sensors collect images of all the targets, the two-dimensional displacement of the targets is calculated through a digital image correlation algorithm, the absolute coordinates of the datum points are transmitted to a monitoring section step by step according to the cascade transmission principle, and therefore absolute measurement of tunnel vault settlement and peripheral convergence is achieved. For displacement prediction, an improved tangent angle algorithm based on coordinate transformation is provided, prediction models are flexibly switched according to the size of an improved tangent angle, and the early warning accuracy and reliability during data missing or fluctuation are effectively improved. The technical problems that in the tunnel construction environment, the view field is blocked, benchmark transmission is difficult, and a traditional prediction method is inaccurate are solved.

The application relates to the technical field of optical detection, and discloses a single-time absolute measurement system and method for a reflecting surface shape, which comprises a spectrum separation unit, a wavefront measurement and collection unit and a surface shape recovery unit; the spectrum separation unit divides a light beam emitted by a light source into a reference light beam and a test light beam, a beam splitting optical wedge is used to superimpose a linear phase carrier frequency on the test light beam and project the test light beam to a measured mirror; the wavefront measurement and collection unit receives the reference light beam and the test light beam reflected back, performs two-dimensional shearing through a chessboard grating, and records a lateral shearing interference pattern of single-time exposure by means of a photoelectric detector; the surface shape recovery unit performs frequency domain demodulation on the interference pattern, intercepts a first-order spectrum component to obtain a demodulation complex amplitude, eliminates a system common path error through a conjugate multiplication operation, extracts an absolute phase gradient field, and constructs a Poisson equation to calculate an absolute surface shape height distribution of the measured mirror. The application does not need multi-step phase shifting, reduces environmental sensitivity, simplifies an optical structure and reduces system measurement error.

The invention relates to the technical field of optical detection, and discloses a reflection surface shape single absolute measurement system and method, and the system comprises a frequency spectrum separation unit, a wavefront measurement collection unit and a surface shape recovery unit. The spectrum separation unit divides a light beam emitted by the light source into a reference light beam and a test light beam, and a beam splitting optical wedge is used for superposing a linear phase carrier frequency for the test light beam and projecting the test light beam to a tested reflector; the wavefront measurement and acquisition unit receives the reference light beam and the reflected test light beam, two-dimensional shearing is carried out through a chessboard grating, and a transverse shearing interferogram of single exposure is recorded by a photoelectric detector; and the surface shape recovery unit performs frequency domain demodulation on the interferogram, intercepts a first-order frequency spectrum component to obtain a demodulation complex amplitude, eliminates system common-path errors through conjugate multiplication operation, extracts an absolute phase gradient field, and constructs a Poisson equation to calculate absolute surface shape height distribution of the measured reflector. According to the invention, multi-step phase shift is not needed, the environmental sensitivity is reduced, the optical structure is simplified, and the system measurement error is reduced.

This invention proposes a high-precision optical analytical balance, relating to the field of precision measuring instruments. It includes a base upon which interconnected optical, weighing, and display units are sequentially mounted. This invention achieves measurement through pure optical detection of the mass-to-displacement conversion process, eliminating any additional electromagnetic contact and thus completely eradicating measurement errors introduced by feedback forces and electrostatic adsorption in traditional balances. Furthermore, by using the fundamental physical constants of laser wavelength and gravitational acceleration as references, the measurement chain is short, fundamentally eliminating the long-term drift problem caused by component aging and magnetic flux changes in electromagnetic balances, achieving absolute measurement with "wear-free scale." In addition, the measurement results can be directly traced back to the basic units of length (speed of light / wavelength) and acceleration, conforming to the trend of quantization and constantization in the International System of Units (SI), which has significant metrological implications.

The application discloses a kind of liquid scintillation double-nucleus simultaneous quantitative measurement methods based on mixed spectrum, comprising preparing double-nucleus mixed sample;Establish the spectrum theoretical description model of single nucleon;T pipe, D pipe energy spectrum is solved by using nonlinear fitting method jointly;T pipe and D pipe count value are obtained by being based on the theoretical description model to the T pipe, D pipe energy spectrum and being solved spectrum;The TDCR liquid scintillation system with T, D pipe energy spectrum output function in the application does not need a large number of pre-calibration work and standard quenching series source, does not depend on the accuracy of calibration, compared with function fitting stripping method, T, D spectrum is calculated simultaneously in the process of spectrum analysis, and absolute measurement is realized based on the mutual constraint of parameters.

This invention provides a simulation verification method for LiDAR in blade internal inspection based on digital twins, belonging to the field of digital twin technology. This method acquires an initial 3D digital twin model and generates simulated point cloud data. It then combines this data with measured point cloud data collected by an inspection robot for spatial registration and deviation analysis. When the spatial deviation does not meet the convergence condition, the initial 3D digital twin model is corrected. Finally, a verification report including a credibility score and accuracy is generated. This method breaks through the limitations of traditional unidirectional mapping of digital twin models, achieving adaptive optimization and accuracy calibration of the digital twin model based on measured data. It effectively solves the problems of difficulty in distinguishing data noise from real defects and increased deviation between the digital model and the physical entity in blade internal cavity inspection. It also solves the problem of lacking an absolute measurement benchmark in hidden spaces, improving the reliability of detecting internal defects in complex surfaces.