818 results about "Fast measurement" patented technology

The invention relates to a concrete working performance measurement method and system based on a multi-modal visual large model, and solves the problem that rapid detection of concrete working performance parameters is troublesome, and the method comprises the steps: based on the spatial semantic understanding capability of the multi-modal visual large model, combining a multi-view stereoscopic vision and structured light scanning technology, and calculating the working performance of concrete; reconstructing a three-dimensional geometric structure of the concrete slurry, extracting morphological characteristic parameters, and forming characteristic vectors; inputting the feature vectors into a pre-trained multi-task neural network, fusing the spatial-temporal features and combining a rheological algorithm to identify various working performance parameters; integrating identification results for at least three times by adopting integrated learning, and verifying parameters based on a fluid dynamics basic equation through a fluid simulation platform; and based on the verification result, generating a mix proportion optimization suggestion containing the material components. The method has the advantages that non-contact rapid measurement of concrete working performance parameters is achieved, precision and efficiency are improved, and mix proportion optimization suggestions are provided.

A time-of-flight based distance measuring method and a time-of-flight based distance measuring system are provided. The distance measuring method includes: sending N consecutive pulses from a transmitter side intermittently, N being a positive integer greater than one, wherein the N consecutive pulses are reflected by a target object, and a reflection signal is generated accordingly, during arrival of the reflected signal at a receiver side, sampling the reflected signal multiple times according to a predetermined sampling interval within a predetermined sampling duration and accordingly generating a sampling result; detecting time of flight of a single pulse of the N consecutive pulses traveling from the transmitter side to the receiver side according to the sampling result; and measuring a distance between the target object and a reference position according to the time of flight. The distance measuring method maintains good measurement quality, measures the distance rapidly, and consumes low power.

The invention discloses a rapid measurement method and system for geometric irregularity of a track in a turnout zone. The method comprises the steps that complete three-dimensional point cloud data of the surface of a railway turnout steel rail are obtained in real time through a multi-angle line structure laser scanner on a special detection vehicle body; accurate attitude and position data of the detected vehicle body in the measurement process are obtained in real time through an inertial navigation measurement unit and an odometer; obtaining a high-precision pose of a detected vehicle body through a robust dead reckoning method of an IMU (Inertial Measurement Unit) assisted by a speedometer dynamic lever arm value based on a variable wheel-rail contact point; constructing a turnout area three-dimensional point cloud model; extracting geometric irregularity key points of turnout steel rail point cloud from the turnout area three-dimensional point cloud model; calculating parameters of track gauge, horizontal and rail direction irregularity and unevenness; the special detection vehicle body can quickly and stably pass through a turnout area to complete continuous and accurate measurement of geometric irregularity of a track.

The invention provides a frequency-modulated continuous wave laser ranging device based on frequency shift double optical combs, which integrates frequency-modulated continuous wave and double optical comb technologies and comprises an FMCW light source, a beam splitter, a detection and reference light channel, a beam combiner, a photoelectric detector and a processing module. The FMCW light source outputs linear frequency sweeping laser which is divided into two paths through the beam splitter, and the detection light channel detects a target through the first optical comb generator and the circulator. The frequency fFS of the reference optical channel is increased through a frequency shifter, optical combs with different comb tooth intervals are generated by a second optical comb generator, and the fFS and the repetition frequency difference delta fR are in a non-integer multiple relation, so that interference is effectively avoided. After being combined by the beam combiner, the two paths of signals are converted into beat frequency signals by the photoelectric detector, and then time domain signals are spliced by the processing module by using coherence, so that the distance measurement precision is improved. According to the invention, the frequency shift double-optical comb technology improves the precision and anti-interference performance; an efficient data processing algorithm ensures rapid measurement and a wide range of application.

The present invention belongs to the field of optical fiber measurement technology, and specifically relates to an optical fiber distributed polarization crosstalk fast measurement device based on optical frequency domain interference. The device comprises a tunable laser source module (1), a device to be measured module (2), an auxiliary interferometer module (3) and a signal acquisition and analysis module (4), and is characterized in that: a high-coherence tunable laser is used to perform fast wavelength scanning on an optical signal, and a linear frequency modulated continuous light (501) is output, which passes through a polarizer (202), a device to be measured (206) and an analyzer (210) in sequence, and a beat frequency signal generated by the interference of a coupling light (704) and a transmission light (701) is obtained in the optical frequency domain, and then an optical path difference and a normalized interference signal amplitude are calculated, thereby respectively determining the polarization crosstalk position and intensity. The present invention, in combination with a tunable laser, gets rid of the dependence on an optical path scanning delay device in polarization crosstalk measurement, greatly improves the speed and dynamic range of polarization crosstalk measurement, and has a compact structure, is stable and reliable, and is easy to implement.

The invention discloses a straight gear shape-free measurement method based on single-group line structured light. The method comprises the following steps: constructing an optical platform coordinate system, carrying out line structured light coordinate system calibration through a spherical calibration body, and calibrating the rotation center of a precision turntable; installing a measured straight gear, establishing a straight gear coordinate system, and adjusting the position of the linear structure optical measuring head, so that the measuring field of view of the linear structure optical measuring head covers a root circle to an addendum circle of the straight gear; the straight gear is installed on a precision rotary table, the straight gear is driven to rotate at a constant speed, a linear structure optical probe scans and collects straight gear contour point cloud data and circular grating angle information, and tooth surface three-dimensional point cloud data is obtained; based on the three-dimensional point cloud data of the tooth surface, extracting an addendum circle, a dedendum circle and an involute tooth profile, and calculating spur gear parameters; performing reverse three-dimensional shape modification tooth surface identification on the shape modification straight gear to generate a three-dimensional deviation diagram; and outputting a measurement result and printing a report. The problems of shape-free rapid measurement, modification tooth surface identification and tooth surface three-dimensional deviation characterization of the straight gear with unknown basic parameters are solved.

The invention relates to the technical field of measuring equipment, in particular to a six-degree-of-freedom parallel mechanism pose high-precision measuring system and method.The six-degree-of-freedom parallel mechanism pose high-precision measuring system comprises a laser emission reference device, an array light spot feature target assembly, a parallel mechanism movable platform and a feature detection and recognition assembly, and the laser emission reference device is arranged at the top of the parallel mechanism fixed platform; the array light spot feature target assembly is arranged above the laser emission standard device and arranged at the bottom of the parallel mechanism movable platform, and the four corners of the bottom of the parallel mechanism movable platform are fixedly connected with the top of the parallel mechanism fixed platform through the six-degree-of-freedom parallel mechanism. The feature detection and recognition assembly is arranged at the bottom of the array light spot feature target assembly and used for recognizing light spot information and target feature information on the array light spot feature target assembly, processing of redundant data is reduced, the measurement period is shortened, and it is ensured that high-precision rapid measurement is achieved.

The invention discloses a method and a system for rapidly measuring cable force of a stay cable based on a digital image correlation method. The method comprises the following steps: acquiring video data of the stay cable; a line segment measurement calibration method is adopted, stay cable texture points serve as feature points, and a feature point selection mechanism is established; establishing a pixel-physical space coordinate mapping model based on a redundant observation method; model parameters are calculated through a collaborative calibration method; performing displacement measurement based on a digital image correlation method; establishing a double-layer feature extraction mechanism to complete local and global feature extraction; weight distribution of the local features and the global features is dynamically adjusted through a weight adaptive fusion strategy; and finally, establishing a double-layer tracking and failure recovery mechanism to complete hierarchical collaboration of coarse-grained global tracking and fine-grained local tracking. And carrying out fast Fourier transform on the dynamic displacement measurement result, and calculating to obtain the cable force. And reliable technical support is provided for non-contact accurate calculation and measurement of the cable force.

The present invention relates to a shield tunnel segment dislocation measurement method based on three-dimensional laser scanning, mainly solving the technical problems of low efficiency, high cost, unsafe high-altitude operation, etc., of existing manual shield tunnel segment dislocation amount measurement technology. The method comprises the steps of: S1, generating a grayscale image on the basis of tunnel laser point cloud data, and performing edge detection on the grayscale image; S2, on the basis of the edge-detected image, collecting statistics about column grayscale cumulative values of the edge-detected image, and realizing circumferential joint position identification by means of threshold determination; S3, selecting a certain angle range on the left and right of a circumferential joint to divide different intervals, collecting statistics about an interval densest radial vector, and calculating a circumferential joint dislocation amount; S4, designing a feature convolution kernel on the basis of shape features of a longitudinal joint, and using the feature convolution kernel to perform convolution calculation on a segment grayscale image in a sliding window manner to identify the position of the longitudinal joint; and S5, selecting point cloud data within a certain range on the left and right of the longitudinal joint, screening for local valid points, and calculating a longitudinal joint dislocation amount. The present invention achieves automatic identification of a longitudinal joint of shield tunnel segments and rapid measurement of a dislocation amount.

Disclosed in the present invention is a three-dimensional laser point cloud-based cable force measurement method for a stay cable. Stay cable actual measurement line shape fitting is performed by utilizing point cloud data, obtained by means of three-dimensional laser scanning, of the stay cable, and on the basis of a finite element calculation method, a line shape that is calculated by a stay cable finite element model and is the same as the actually measured line shape of the stay cable is found, thereby determining an actual cable force of the stay cable, and achieving the purpose of accurately measuring the cable force of the stay cable. According to the present invention, a three-dimensional laser scanning technology is introduced and applied to cable force measurement of a stay cable, and for the defects of a common cable force measurement method, the characteristics of non-contact measurement, high measurement precision, high measurement efficiency and the like of the three-dimensional laser scanning technology are utilized so as to achieve rapid measurement of the line shape and the section size of the stay cable. On the basis of finite element calculation and analysis, the three-dimensional laser point cloud-based cable force measurement method for the stay cable is provided, thereby achieving rapid and efficient measurement of the cable force of the stay cable.

A method for identifying and calculating the volume of over- and under-excavation in tunnels based on laser point clouds belongs to the field of intelligent tunnel construction and blasting quality assessment technology. Technical solution: The scanned point cloud data is denoised; a design contour point cloud is generated and aligned with the centerline of the actual excavated tunnel; the actual collected tunnel excavation point cloud and the design contour point cloud are Delaunay tetrahedralized; the actual tunnel point cloud is traversed, and the vector dot product formed between the point cloud and the triangular sides of the convex hull is calculated; over- and under-excavation areas are identified; a polyhedron is constructed from the design contour point cloud and the actual excavated area point cloud constituting the area; the polyhedron is divided into quadrilaterals, and the volume of each quadrilateral is calculated, thereby calculating the volume of each over- and under-excavation area. Beneficial effects: This invention can quickly measure over- and under-excavation areas and quantities that are difficult to calculate in tunnel blasting quality assessment, and can replace cumbersome and time-consuming total station and manual measurement methods; this method has the advantages of high precision, high efficiency, and high flexibility.

The invention relates to the field of measurement, in particular to an intelligent concrete aggregate moisture content rapid determinator, which comprises a signal transmitting and receiving module, which transmits electromagnetic waves at a series of set frequencies and collects reflection signals at each frequency; the signal processing module is used for carrying out signal processing on the collected reflected signals; and the dielectric constant calculation module is used for calculating the dielectric constant of the measured medium under each frequency according to the signal characteristic parameter and the relationship between the signal and the dielectric constant of the medium. The method has the advantages that the water content of the concrete aggregate can be continuously and rapidly measured, the damage degree to the concrete aggregate is small, a hardware circuit is simple, and the cost of corresponding measuring equipment is low. Compared with other various methods for measuring the water content of the concrete aggregate, the method has the advantages that portability is achieved, and the FDR has obvious advantages from the comprehensive characteristics of accuracy, continuity, equipment cost and the like.

The invention provides an integrated measurement device, a beam parameter quality control method and related equipment, relates to the technical field of particle radiotherapy, and is used for rapidly measuring beam parameters of pencil beam scanning points in arc proton therapy in real time. Comprising a plurality of measurement units which are arranged at intervals along a beam transmission direction, the plurality of measurement units are periodically and repeatedly arranged to form a two-dimensional orthogonal sampling grid, and time-space distribution data of a beam cross section are synchronously acquired through one-time beam output; the analysis module is used for processing the beam parameters output by the signal acquisition and processing module in real time, and the beam parameters comprise the scanning point position, the beam spot size, the charge quantity and the range; beam parameters of a pencil beam scanning point can be rapidly measured in real time, and accurate and efficient measurement is ensured; according to the matched beam parameter quality control method, the accuracy and reliability of arc proton treatment are improved through operations such as multi-angle measurement, parameter correction, quality control interval optimization and real-time dynamic adjustment.

The invention relates to a rapid measurement system and method for the axis of a heat insulation pipeline, and the method comprises the steps: obtaining the feature information of the pipeline through the cooperation of multiple sensors and a movement mechanism, calculating the center of the metal inner wall of the heat insulation pipeline through a provided center searching algorithm, and calculating the center of the metal inner wall of the heat insulation pipeline according to the large-size features and mechanism movement control. Feature information of the heat insulation pipeline is rapidly captured, and the pipeline axis is calculated. The system comprises a laser distance measuring sensor, an eddy current sensing system, a circumferential rotating device, a radial feeding device, an axial feeding device, a high-speed data acquisition system, upper computer software and the like.

The invention discloses an inverse calculation method for obtaining multi-optical parameter spectral data of a turbid medium in real time. Scattered light signal measurement values, namely diffuse reflection rate Rd, diffuse transmission rate Td and forward transmission rate Tf, of the turbid medium sample can be accurately and rapidly obtained through one-time measurement at each measurement wavelength center value lambda. The method is simple and easy to operate, collimation transmittance signals attenuated along with the sample thickness D index do not need to be measured, sample attenuation coefficients do not need to be solved, the thickness D value of the prepared turbid medium sample can be two times or more of the thickness allowed by an existing method, therefore, the difficulty and time for preparing the sample with the small thickness D value can be remarkably reduced, and turbid medium multi-parameter spectral data can be obtained in real time. According to the inverse calculation method, a sample signal measurement system and sample preparation steps can be remarkably simplified, and turbid medium multi-parameter spectral data consisting of an absorption coefficient mu a, a scattering coefficient mu s and an anisotropy coefficient g can be accurately and quickly obtained on the basis of accurately and quickly measuring scattered light signal spectral data.

The invention discloses a spatial non-cooperative dynamic target approach visual detection method, and relates to the technical field of optical visual sensor detection, and the method comprises the steps: building a spatial non-cooperative dynamic target approach visual detection system software and hardware frame structure, and employing a deep residual shrinkage network to achieve target detection in a strong noise interference environment; establishing a coaxial three-dimensional vision measurement model to realize rapid measurement of target three-dimensional point cloud and motion parameters; the motion state of the target is subjected to reinforcement learning training, the motion condition of the target is sensed and predicted, and support is provided for a flight carrier to intelligently sense the target and make a maneuver decision. The method is suitable for high-precision and intelligent detection in the approaching process of a space dynamic target, and has important significance in guaranteeing detection and perception in the fields of spacecraft short-distance capture, near-earth asteroid early warning, air refueling docking and the like.

The present application relates to the field of measurement technology, and in particular to a rapid measurement system for aviation blades based on a four-line structured light sensor, wherein the measurement system comprises: four line structured light sensors and a calculation processing module mounted on a three-dimensional coordinate measuring machine; determining the equation of the laser plane in the camera coordinate system based on a target; solving the three-dimensional coordinates of the target point on the intersection of the laser plane and the blade in the camera coordinate system based on the equation; establishing a transformation relationship between the camera coordinate system and the machine coordinate system of the three-dimensional coordinate measuring machine, converting the target point to the machine coordinate system, and realizing three-dimensional scanning measurement; obtaining the point cloud data of the standard sphere in the sensor external parameter calibration module, fitting and outputting a point cloud sphere; using the center of the point cloud sphere as the measurement reference, combining the measurement data of multiple line structured light sensors to obtain the measurement result. Through the present application, only one-dimensional movement along the Z axis of the three-dimensional coordinate measuring machine is required to complete the measurement, thereby improving the measurement efficiency.

The invention discloses a method for detecting the head height of a bolt, and the method comprises the following steps: carrying out the projection of the head of the bolt through employing a structured light 3D camera, and obtaining the three-dimensional point cloud data of the head of the bolt; after abnormal points are processed, a bolt head area template is constructed; bolt head positioning is carried out on the bolt head area template and the actual detection area; selecting a plurality of local point cloud data in the bolt head area, and setting the local point cloud data as bolt head positions; selecting a plurality of local point cloud data on the outer side of the bolt head area, and setting the local point cloud data as bolt reference surface positions; and calculating the distance between the bolt head position and the bolt reference surface position by using a point-to-plane algorithm. The bolt head height detection method provided by the invention has the advantages of one-key operation, simple operation, fast measurement speed, automatic data and picture storage, and solving of pain points which cannot be traced by conventional contact measurement.

The invention discloses a tunnel back break identification and volume calculation method based on laser point cloud, and belongs to the technical field of tunnel intelligent construction and blasting quality evaluation. According to the technical scheme, point cloud data obtained through scanning are denoised; generating a design contour point cloud and aligning the design contour point cloud with an actual excavation tunnel center line; performing Delaunay tetrahedron on the actually acquired tunnel excavation point cloud and the designed contour point cloud; traversing the actual point cloud of the tunnel, and calculating a vector dot product formed between the point cloud and the triangular edge of the convex hull patch; judging an over-excavation and under-excavation area; and constructing a polyhedron by using the design contour point cloud and the actual excavation area point cloud which form the area, dividing the polyhedron into quadrangles, and calculating the volume of each quadrangle, thereby calculating the volume of each over-excavation and under-excavation area. The method has the beneficial effects that the over-excavation and under-excavation areas and the over-excavation and under-excavation amount which are difficult to calculate in tunnel blasting quality evaluation can be rapidly measured, and a tedious and time-consuming total station and a manual measurement method can be replaced; the method has the advantages of high precision, high efficiency, high flexibility and the like.

The utility model relates to a device for measuring the three-dimensional shape of a sample with non-uniform reflectivity. The device comprises a structured light illumination element DLP, a collimating lens group, a polarizing beam splitter, a 1 / 4 wave plate, a motor, a dispersion tube lens, an objective lens, an objective table for placing the sample to be measured, a focusing lens, a dichroic mirror, a first optical filter, a first camera, a total reflection prism, a second optical filter, a second camera and a microprocessor, the 1 / 4 wave plate, the motor, the dispersion tube lens, the objective lens, the objective table, the focusing lens, the first camera and the second camera are perpendicular to the same optical axis, and the structured light illumination element DLP, the polaroid and the collimating lens group are parallel to the same optical axis and are perpendicular to the optical axis reflected by a tested sample. According to the utility model, the structure is simple, the first camera and the second camera can rapidly acquire images of two wavebands of a sample with non-uniform reflectivity based on the structured light illumination element DLP, and the microprocessor rapidly measures the height difference of the sample with non-uniform reflectivity based on the images of the two wavebands.

The invention relates to the technical field of coal moisture content measurement, in particular to a coal moisture content rapid measurement method and system based on a convolutional neural network. Coal flow hyperspectrums, images and pulse flows are synchronously collected, aligned segmentation is executed, and evaporation stages are divided based on spectral reflectivity time sequence fluctuation to obtain segmented codes; and constructing water film roughness distribution by combining image gray and gradient features, cascading a time-space sequence to generate a fusion feature vector, implementing time scaling and interpolation filling on an effective fragment according to a belt speed, and aggregating and outputting the coal moisture content. According to the method, hyperspectral and image pulse streams are associated to align data and eliminate missing frames, reflectivity time sequence fluctuation is analyzed to divide evaporation stages and establish indexes, gray and gradient features are fused to construct a roughness texture matrix, space-time sequences are cascaded to generate feature vectors, and sequence scaling and interpolation filling are dynamically executed according to belt speed. Speed interference is eliminated, spectrum deviation is corrected, and finally accurate analysis of the coal flow moisture under the variable running speed working condition is achieved.

The invention relates to a distortion degree measuring system and method based on correlation operation, and the system comprises a signal source which is a to-be-measured signal source for outputting a mixed waveform comprising a fundamental wave and each harmonic component; the fundamental wave extraction module is used for separating and extracting a fundamental wave component of which the waveform is a single-frequency square wave from the signal to be detected; the phase-locked loop frequency multiplication module is used for receiving the fundamental component and locking and extracting a sine wave signal containing the fundamental component and a harmonic component through a phase-locked loop containing a programmable frequency divider; the correlator module is composed of a multiplier circuit and a low-pass filtering and amplifying circuit, receives a to-be-measured signal serving as an input signal and a sine wave signal serving as a reference signal, and outputs a direct-current component; and the single chip microcomputer is configured with the programmable frequency divider, samples the direct current component output by the correlator module, calculates the relative amplitude and the total harmonic distortion degree of the fundamental wave component and the harmonic component, and outputs the total harmonic distortion degree. The beneficial effects are that the measurement system and the signal processing method are suitable for signal harmonic analysis under a complex harmonic environment and a low signal-to-noise ratio condition, a high-performance processor and a computing power requirement are not needed, and the system takes an analog circuit as a main body and has the advantages of high measurement speed, high accuracy, low system cost and the like.

The present invention discloses a method for measuring the lead of steel bars based on 3D vision. First, a depth map of the steel bars is captured by a 3D camera, and then the threshold segmentation algorithm is used to extract the rectangular contour of the steel bars and extract the center line of the rectangle. Next, the depth values of all points on the center line are obtained and exported to an Excel table. Subsequently, based on the exported Excel table, Python is used to draw a function graph of the pixel coordinates and depth values of the points on the center line. Then, the filtering algorithm is used to optimize the function graph and find the maximum points. Finally, two maximum points between the specified pixel coordinate points are selected to calculate the lead of the steel bars. The present invention realizes the non-contact measurement function of the lead of steel bars with automation, and has a relatively fast measurement speed and good measurement effect for the lead of steel bars. It also avoids the large lead measurement error caused by the measurement method based on 2D vision. This measurement method has high measurement accuracy and is less affected by the environment, and is suitable for being widely promoted and used.

The invention discloses an optical system which comprises a first lens, an optical filter and a second lens which are sequentially arranged in the optical path transmission direction, and further discloses a measuring device which comprises the optical system, the lower end of a detector cold shield is connected with a transition block, the lower end of the transition block is connected with a supporting column, the lower end of the supporting column is connected with a shell, and a Dewar flask is arranged on the shell. A detector is arranged on the end face, located in the detector cold screen, of the transition block. A turntable and a turntable base are sequentially connected below the shell; the imaging optical system is integrated into the structure of the vacuum cavity of the refrigeration type long-wave focal plane infrared detector, so that the refrigeration type long-wave focal plane infrared detector has a large-view-field imaging function, and the measuring device is portable and can meet the requirement for rapidly measuring atmospheric radiation spatial and temporal distribution.

The invention discloses a tunnel blasting damage rapid measurement method and system based on a wall-climbing robot, and the method comprises the following steps: S1, laying a three-dimensional optical fiber network, recording the coordinates of each section of optical fiber, and building a mapping relation between an optical fiber node and a space coordinate position; s2, constructing an initial three-dimensional wave velocity model of the tunnel rock mass; s3, correcting the velocity fields of the reflected wave and the winding wave to obtain an optimized wave velocity model; s4, exciting artificial seismic sources at a plurality of positions in the tunnel through a wall-climbing robot with an electromagnetic vibration exciter, and performing data acquisition by a DAS system through an optical fiber network; s5, processing the data acquired in the step S4, carrying out wavelength separation on the reflected wave and the diffracted wave, and respectively carrying out migration imaging on the reflected wave and the diffracted wave after classification; and S6, fusing imaging results of the reflected wave and the diffracted wave through a weight coefficient, and generating a comprehensive geologic model.

This invention proposes a method for detecting chemical oxygen demand (COD) in water based on laser spectroscopy, comprising the following steps: Step 1, shining a laser beam into a water sample to be tested, causing the water sample to generate a light signal upon laser excitation; Step 2, receiving the light signal using a spectrometer, converting it into an electrical signal, and then into a digital signal; Step 3, receiving the digital signal through a data processing system to form a spectral curve; Step 4, calculating the relative integrated fluorescence intensity I based on the information in the spectral curve. T λ1 and λ2 are the starting and ending wavelengths of the fluorescence spectrum, respectively, and Iλ represents the fluorescence intensity at wavelength λ. r This represents the light intensity of the Raman peak after subtracting the fluorescence background; Step 5: Calculate the COD value of the water sample according to the chemical oxygen demand formula for water quality. The chemical oxygen demand formula for water quality is COD = KI T +C. The above detection method can greatly reduce the influence of various interference factors on COD detection results, and has the advantages of high sensitivity, fast measurement speed, convenient measurement, and high accuracy.

According to the CDSEM rapid measurement method and device, the medium, the program product and the terminal, optimization of the CDSEM measurement process is achieved through the technical means of introducing measurement position compensation and presetting the automatic focusing voltage value. The method comprises the following specific steps: acquiring coordinates of a plurality of points to be measured, generating a measurement sequence based on the coordinates, and carrying out multiple goods passing operations. And in each goods passing operation, the offset errors and the current focusing parameters of all the measurement points are recorded, the optimal compensation error and the optimal focusing parameter are generated, and the optimal compensation error and the optimal focusing parameter are applied to coordinate compensation and simplified measurement operation. The efficiency of the CDSEM measuring system is remarkably improved, and particularly, the requirement for rapid and accurate measurement is effectively met in the mass production stage. Therefore, the repeated calibration and focusing steps in the traditional CDSEM measurement process are avoided, the measurement time is greatly reduced, the wafer throughput of a CDSEM machine table is greatly improved, and the capacity of the machine table is improved.

The invention discloses a method for rapidly measuring the thickness of a thin film based on Chirp-Z transformation. The method comprises the following steps: 1) collecting spectral data; 2) data preprocessing; 3) CZT (linear frequency modulation Z transform) parameter configuration and CZT frequency spectrum calculation; according to the method, after the processed data collected by the spectrograph are received, data preprocessing is carried out, spectral analysis is carried out through Chirp-Z transformation, the spectrum peak value is obtained for accurate positioning, the film thickness is calculated through the effective refractive index, and therefore efficient and high-precision film thickness measurement is achieved.

The invention provides a size detection device for glass production and manufacturing, and relates to the technical field of glass size detection. The size detection device for glass production and manufacturing comprises a working table, an adjusting mechanism is arranged in the working table, four positioning plates distributed in a square shape are arranged on the upper surface of the working table, the four positioning plates are concentric with the working table, the adjusting mechanism drives the four positioning plates to synchronously move towards or deviate from the central point, and the adjusting mechanism is arranged on the upper surface of the working table. The side walls of the two oppositely-distributed positioning plates are fixedly connected with a connecting plate, the outer side of the connecting plate is connected with a scale plate, the device further comprises a top plate and a moving mechanism which are located above the workbench, and the left side of the lower surface of the top plate is slidably connected with a downward laser range finder through the moving mechanism. And a detection mechanism is arranged in the middle of the top plate and drives to-be-detected glass to perform rotary detection. Through the adjusting mechanism and the positioning plate, the center point of the glass can be conveniently and accurately found, and then rapid measurement is achieved.

A method for high-efficiency combined machining of an aspheric optical element comprises the steps that a tool clamp is manufactured according to the shape of the optical element to be machined, the lower surface of an optical element blank is ground and polished, and the optical element blank is fixed to the tool clamp; performing aspheric surface forming processing on the upper surface of the optical element blank through rough grinding and accurate grinding to obtain an aspheric surface sample piece; measuring the surface shape data of the aspheric sample piece by using a contourgraph; the surface shape data are imported into an air bag polishing machine tool, an NC code for compensation machining is obtained through calculation, a tool clamp and the aspheric surface sample piece are fixed to a transition clamp of the polishing machine tool together, and rough polishing and fine polishing are conducted on the upper surface of the aspheric surface sample piece through different air bag polishing heads; and after machining is completed, measuring the surface shape data of the aspheric surface sample piece by adopting a contourgraph, soaking the aspheric surface sample piece and the tool clamp in an acetone solution after the aspheric surface sample piece is qualified, and taking out the sample piece. The process is scientific and reasonable, the surface shape of the element can be rapidly measured, the clamping error is reduced, the machining quality and the machining efficiency are improved, and the production cost is reduced.