112 results about "Nonlinear calibration" patented technology

The invention relates to a method for continuously quantitative evaluation of pore structures of reservoir strata by utilizing nuclear magnetic resonance well logging data, so as to divide types of the reservoir strata. The method comprises the following steps of: classifying T2 spectrums according to parameters reflecting differences of reservoir strata, and carrying out a nonlinear calibration method on different T2 spectrums to obtain a continuously distributed capillary pressure curve of the reservoir strata; obtaining continuous reservoir stratum pore throat radius distribution and pore structure parameters by utilizing the nuclear magnetic capillary pressure curve; and evaluating the pore structure of each reservoir stratum on the basis of the nuclear magnetic capillary pressure curve, the features of the reservoir stratum pore throat radius distribution and the pore structure parameters, and dividing types of the reservoir strata. Through the adoption of the method, the nuclear magnetic capillary pressure curve on each depth point can be continuously obtained by utilizing the nuclear magnetic resonance well logging data, the pore structure of each reservoir stratum can be quantitatively evaluated according to the reservoir stratum pore throat radius distribution and the pore structure parameters of the reservoir stratum, and the types of the reservoir strata are classified, therefore, the exploitation and development efficiency of complicated oil-gas reservoir is improved.

The invention discloses a near infrared spectrum nondestructive testing method and a near infrared spectrum nondestructive testing device for material component content. The method comprises the following steps of: collecting calibration set samples by using a spectrometer, pretreating a spectrum, selecting an optimal calibration sample set through sample optimization and establishing a nonlinear calibration model by using the optimal calibration sample set, collecting spectrum samples with unknown component content by using the spectrometer, pretreating the spectrum in a mode which is the same as that of pretreating the calibration set samples, and detecting the component content of the unknown sample through the established nonlinear calibration model. The method and the device can effectively solve the problems of complex calibration model, slow training speed and difficult hardware implementation in the conventional near infrared nondestructive testing method for the material component content and obviously improve the accuracy and stability of a nondestructive testing result of the material component content.

An embodiment provides a continuous-time delta-sigma modulator for analog-to-digital conversion. The modulator includes a signal path generating including a ring voltage controlled oscillator driven by an analog input signal. The signal path produces digital values by sampling the ring voltage controlled oscillator. A calibration circuit measures nonlinear distortion coefficients in a replica of the signal path. A nonlinearity corrector corrects the digital values based upon determined nonlinear distortion coefficients. Preferred embodiment ADC ΔΣ modulators do not require any analog integrators, feedback DACs, comparators, or reference voltages, and do not require a low jitter clock.

The invention belongs to the technical field of measured calibration, and relates to a calibration process for solving camera inside and outside parameters by using a single digital camera for shooting a group of images based on LCDs, particularly to a digital camera nonlinear calibration method based on the LCDs, which comprises the following steps: designing and drawing a calibration chart through programming, wherein the calibration chart has round marking points in different sizes; displaying the calibration chart on the screen of a liquid crystal display; then shooting images by a digitalcamera in the mode of rotating around an optical axis; and then computing the camera inside and outside parameters by using the shot images; extracting sub-pixel contour edges in the images by usingthe complete pure flatness of the liquid crystal display and easy detection of centralized positioning height and sub-pixel edge contour of the round marked points, and obtaining a calibration resultof digital camera parameters by a nonlinear optimization method. The calibration method has the advantages of simple and easy operation, small and agile use equipment, good calibration precision, goodquality, strong optimization degree and the like.

An alignment method enabling reduction of the effects on throughput and nonlinear correction for the optimum shot alignment for each wafer. According to the present invention, the nonlinear error is corrected by EGA calculation having higher order terms. One or more correction conditions (correction coefficients) are selected with reference EGA log data or overlay measurement data in advance for each process condition and registered in an exposure apparatus. At the time of lot processing of the exposure apparatus, the shot alignment of several sample shots is detected to detect the trend in nonlinear error and a single optimum correction coefficient is selected based on this from the registered plurality of correction coefficients. Further, after ordinary EGA, higher order EGA is performed using the selected correction coefficient to correct the nonlinear component and position each shot area.

The invention belongs to the technical field of analog-digital converters, and particularly relates to a capacitive nonlinear calibration circuit of a bit-by-bit approximation analog-digital converter and a method. The circuit structurally comprises a digital-analog converter, a clock control circuit, a calibration logic control circuit, an error measurement and storage circuit, a summator logic circuit, a comparator circuit and a bit-by-bit approximation analog-digital converter logic circuit. The method comprises the steps that the calibration logic control circuit is switched on, the analog-digital converter starts to carry out error measurement, and the error measurement and storage circuit calculates and stores the error factors of capacitors on all bits respectively; after the error factors are all stored, the calibration logic control circuit is switched off, and the analog-digital converter adds output codes and the error factors through the summator to obtain the final calibration output code. The capacitive nonlinear calibration circuit and the method are suitable for the high-precision low-power-consumption bit-by-bit approximation analog-digital converter, and mainly have the advantage that under the condition of not adding extra analog circuits, nonlinear errors caused by stray capacitors and capacitor array mistaching in a calibration capacitor array and hardware and power consumption cost are low.

The invention discloses a novel calibration method and a system for gas sensors and particulate matter sensors. The method comprises the steps of acquiring cross-over experiment data of parameters with influence on measurement accuracy of the sensors, and inputting a large number of laboratory data of different parameters to an established calibration model, so as to obtain linear and nonlinear calibration parameters of different sensors. The calibration model adopts a universal artificial-intelligence big data algorithm platform in view of different parameters, linear / nonlinear cross corresponding curves, containing different parameters, of temperature, humidity, wind direction, wind speed, atmospheric pressure, interference gas and sensor element aging of the sensors can be automatically extracted and obtained from experimental tank cross-over experiment parameter data through establishing relatively-deep artificial neural network or intelligent gene algorithm models, and random complicated nonlinear calibration model can be mapped, so that the robustness and adaptability are very high.

The invention discloses a phase measuring profilometry system nonlinear correction method combining geometric calibration. According to the phase measuring profilometry system nonlinear correction method combining geometric calibration, a target is scanned through the phase measuring profilometry to obtain an accurate phase, average brightness and brightness modulation, the accurate phase and the average brightness are utilized to calibrate a protector and a camera shooting device respectively, nonlinear response of the projector is obtained according to the accurate phase and a shot structured light image to establish a gray level lookup table, the gray value of the image is pre-compensated by utilizing the gray level lookup table before three-dimensional scanning is carried out on the projected structured light image, and therefore the purpose of carrying out nonlinear correction on a measurement system is achieved. The phase measuring profilometry system nonlinear correction method combining geometric calibration can be used for geometric calibration and nonlinear correction of the phase measuring profilometry system, organically combines geometric calibration of the measurement system and nonlinear correction, and has the advantages of convenient operation, high correction accuracy and high execution efficiency.

The invention provides an elastic aircraft flight dynamics modeling method based on nonlinear aerodynamic force order reduction, which is suitable for engineering and is used for realizing elastic aircraft flight dynamics simulation, especially gust response high-precision and high-efficiency simulation under the condition that a low-speed aircraft encounters large-amplitude gust. The method comprises the following steps: firstly, establishing a rigid-elastic coupling kinetic equation of the elastic aircraft, then solving generalized aerodynamic force in a given motion or incoming flow state based on CFD, and obtaining training input and output signals of a reduced-order model; an ARMA model and an RBF neural network model are adopted to establish a linear aerodynamic order reduction model and a nonlinear correction model respectively, and the linear aerodynamic order reduction model and the nonlinear correction model are combined to obtain a nonlinear aerodynamic order reduction model; and then coupling the nonlinear aerodynamic reduced-order model and the rigid-elastic coupling kinetic equation to carry out flight kinetic simulation on the elastic aircraft. Compared with a traditional simulation method based on surface element method aerodynamic force, the method is high in precision and efficiency compared with a CFD / CSD coupling analysis method, and has high engineering value.

The invention relates to a method and a system for nonlinear correction of a radio frequency power amplifier. The method comprises the following steps of: S1. carrying out negative feedback correction on an input signal according to a feedback signal and outputting a negative feedback signal; S2. carrying out pre-distortion correction on the negative feedback signal and outputting the signal subjected to pre-distortion to the radio frequency power amplifier; and S3. collecting the signal amplified through the radio frequency power amplifier, generating the feedback signal and returning to the step S1. The method and the system for nonlinear correction of the radio frequency power amplifier adopt a method of combining the pre-distortion correction and closed-loop negative feedback correction, and are realized in a digital domain; and in comparison with a conventional nonlinear correction method, the correction effect is more accurate, the dependence on a device is smaller and the system is more stable.

The invention discloses a binary phase shifting pattern based three-dimensional measurement method, which is characterized in that focused projection equipment and a camera shooting device are utilized, a plurality of groups of binary pattern sequences coded by spatial square waves are projected to a measured objected by using the projection equipment, each group of patterns is provided with a specific spatial frequency, the spatial frequency of one of the groups of patterns is 1, adjacent patterns in each group of patterns have a fixed phase shifting amount therebetween, the total phase shifting amount is a cycle, corresponding pattern sequences are recorded by using the camera shooting device, a phase calculation formula of phase measuring profilometry is applied to image groups with different frequencies respectively so as to acquire a fundamental frequency phase and a plurality of high frequency truncation phases, an absolute phase is acquired according to a temporal phase unwrapping method, and three-dimensional coordinates of the measured object are determined according to the phases and system calibration parameters. The method disclosed by the invention can be applied to high-speed and high-precision three-dimensional measurement. The binary phase shifting pattern based three-dimensional measurement method has the advantages of ability of being free of nonlinear correction, high scanning speed, simple system calibration, and ability of accurately measuring scenes with great depth variations.

The invention relates to an on-orbit radiation nonlinear calibration method of a Fourier transform infrared spectrometer, and belongs to the technical field of on-orbit calibration methods of infraredloads. The method comprises the following steps of: step 1, closing the temperature control after the temperature control of an inner blackbody on a satellite reaches the balance of a highest temperature control point, wherein an instrument is periodically aligned with the inner blackbody and a cold space for observation during the inner blackbody temperature control, inner blackbody free temperature reduction and inner blackbody balancing periods, step 2, screening remote sensing data packets observed by the inner blackbody and downloaded by the satellite to obtain a plurality of inner blackbody observation remote sensing data; step 3, calculating uncalibrated spectral digital quantity and spectral radiance observed in the inner blackbody and the cold space; step 4; carrying out least square fitting on every channel in spectral band to obtain nonlinear calibrated coefficients; step 5, calculating target spectral brightness of earth observation by the instrument. The method can determine the nonlinear response relation of the Fourier transform spectrometer and improve the calibration precision and the data inversion accuracy.

The invention discloses a temperature measuring method and circuit adopting the reference voltage compensation technology. The method is characterized in that a reference voltage source supplies power for a platinum resistor temperature measuring bridge while the temperature of the reference voltage source is measured through a digital temperature measuring sensor attached to the surface of the reference voltage source, and the temperature is transmitted to a FPGA chip; the platinum resistor temperature measuring bridge converts the measured temperature into voltage change, and the voltage change sequentially passes a filter circuit, an operation amplifier and an A / D conversion module and is input into the FPGA chip; the FPGA chip performs the error compensation and calculation of the measured temperature according to the temperature error calibration model of the reference voltage source and the nonlinear calibration model of a platinum resistor so as to output the digital quantity of the measured temperature. The method has the advantages that error compensation is performed on the output value of reference voltage, the reference voltage is kept accurate as much as possible during the calculation, and temperature measuring precision is increased to a large degree.

The invention relates to an image full-screen anti-aliasing method and a device for head-up display characters and belongs to the technical field of image processing. The low-frequency flat area of an image and the high-frequency marginal area of the image are differentiated based on the correlation of adjacent pixels. The high-frequency marginal area of the image is selectively subjected to the anti-aliasing treatment based on a weighted Gaussian filtering function. In this way, the uniformity of displayed image lines is ensured, while the defect that an overall image is darker and lower in contrast ratio based on the traditional non-content-based anti-aliasing algorithm can be overcome. Moreover, based on the fact that the images of head-up display characters are rich in high-frequency components and severe in gray discretization, the contrast ratio is improved based on a nonlinear calibration curve. According to the invention, the phenomenon that lines in an original image of a head-up display character are poor in uniformity and the edge of the image is twisted can be effectively improved. The display effect of the overall image of the head-up display character is improved and the real-time performance is high. The entire processing process is shorter than three thousandths of the duration of a whole-frame image. The influence of the system delay is small. The method is simple and easy in hardware implementation.

Predetermined reference voltages v1, v2 are A / D-converted to achieve corresponding digital data d0, d1, d2. Any reference digital values y1, y2 are set in advance so as to satisfy y1 / y2=(v1−v0) / (v2−v0)=1 / 2. Furthermore, calculations of x1=d1−d0 and x2=d2−d0 are carried out to achieve x1, x2. A quadratic curve (quadratic function expression y=f(x)) passing a point D (x1, y1) and a point E (x2, y2) and the origin on the xy coordinate system is set as a linearly correcting expression. A shift value x achieved by subtracting d0from data ds having non-linearity from the A / D converting circuit is corrected by the linearly correcting expression thus achieved to achieve a linearly corrected value y to ds.

The invention discloses a method for increasing the contrast of an OLED display screen, which comprises: firstly, determining the maximum value of the monochromatic brightness total values of a display signal; secondly, calculating the ratios of the maximum value to the monochromatic brightness reference values of all pixels, and dividing the obtained ratios into four ratio intervals which are divided in advance; thirdly, processing the ratios by using different nonlinear calibration modes according to different intervals; and finally, outputting the processed display signal to the OLED display screen for display. By increasing the brightness of the low-light part of a dark field and the brightness of the high-light part of a bright field, the method of the invention improves the detail display of the OLED display screen and increases image contrast, so that the OLED display screen can clearly display image frames in high light.

The invention relates to a ps-grade time frequency measurement circuit and a measurement method thereof. The measurement circuit comprises a circuit channel, an ECL logic control circuit, deltat1 and deltat2 extracting circuits, an integrating-sampling circuit, an ADC converting circuit, an integrating capacitor, a constant-current-source circuit, an FBGA circuit, a single-chip microcomputer control circuit, a keyboard, a display circuit, etc. The measurement method is improved based on simulation of an inner difference method. Through performing unification calibration, device nonlinear calibration, temperature drift calibration, imbalance voltage current calibration, system triggered error calibration and the like on two channels, the calibration method of each system parameter is designed through long-term statistics operation, and the calibration methods are called as system statistics calibration in total. Finally stable and accurate ps-grade time frequency measurement is realized.

The invention relates to an attitude adjustment and nonlinear calibration method for imaging in the identical region of a heterogeneous scene. The attitude adjustment and nonlinear calibration method comprises the following steps: calculating an initial drift angle of satellite imaging and adjusting a satellite yaw angle, transferring into a calibration mode of imaging in the same region of the heterogeneous scene; accurately calculating an image drift size by adopting a top-down time interface step length in an imaging process of the calibration mode, controlling an accurate push-sweeping direction of imaging of a linear array CCD (Charge Coupled Device) through adjusting the satellite yaw angle to ensure that the linear array CCD can be used for sequentially imaging the identical region; and determining whether the obtained image data meets the condition of nonlinear calibration, and if being met, establishing a nonlinear calibration mapping relationship table on the basis of histogram matching histogram matching, and if not, re-determining an imaging scene to continuously execute on-tract calibration so that more image data is obtained. The attitude adjustment and nonlinear calibration method is low in requirement for a ground scene without a more uniform scene; a non-uniform scene can meet a calibration task, each track of satellite operating can realize calibration, with high calibration frequency.

Calibration could be implemented in several stages during the color rendering processes. One possible and efficient place to put the calibration to work is in the screen table itself. In order to make the screen intelligent enough to adjust the factor results from output device characteristics, such as the dot gain, toner characteristics, etc., the method is introduced to create a gamma function with normalized gradation curve. Some color balance adjustment features (contrast, brightness, saturation and color strength) also have been taken into consideration.

The invention discloses a three-dimensional measurement method based on a pulse width modulation fringe. The three-dimensional measurement method consists of three key parts of pulse fringe encoding, pulse fringe defocusing and three-dimensional reconstructing. A pulse fringe is generated from a computer and then moderately defocused through a projector to generate a sine fringe on a reference face for three-dimensional measurement. The invention is advantageous in that (1) as the pulse fringe is a binary fringe, the grayscale value thereof can only be two values (0 and 1), so the measurement is quick; (2) since the nonlinear gamma of the projector can be eliminated simply by slight defocusing the projector, phase errors can be reduced without complex nonlinear calibration; and (3) thanks to less reduction in fringe contrast after the pulse fringe is slightly defocused, the measurement depth problem is overcome.

The invention discloses a beat frequency signal nonlinear correction method in an FMCW distance measurement system, solves the problem of low signal-to-noise ratio caused by influence of frequency modulation nonlinearity on nonlinear correction by means of phase comparison of an auxiliary interferometer in the prior art, and belongs to the technical field of signal processing. The method comprisessteps that S1, Hilbert transform of signals of an auxiliary interferometer is carried out to acquire phase information of the signals of the auxiliary interferometer, the phase information is utilized to acquire an orthogonal basis used for nonlinear correction, and the orthogonal basis comprises frequency modulation nonlinear information; and S2, a measurement interferometer signal is sampled, and the measurement interferometer signal is converted by utilizing the orthogonal basis in the step S1 to finish nonlinear correction. According to the invention, the auxiliary interferometer is usedfor sampling the light source signal, the signal of the auxiliary interferometer is used as the orthogonal basis used in the spectral analysis method to replace the original linear phase orthogonal basis to carry out spectral analysis on the measurement path signal, and the influence caused by frequency modulation nonlinearity and light source mode hopping can be effectively eliminated.

The present invention provides one simple and convenient LED display screen nonlinearity correcting method and device. The technological scheme includes the following steps: constituting nonlinearity correcting curve; forming nonlinearity correcting data; forming nonlinearity memory list storing in nonlinearity memory, reading grey data and scanning; and sending corrected grey data to display screen. The device includes R, G and B grey input unit, R, G and B grey output unit and nonlinearity correcting chip in between.

The invention discloses an intelligent test system based on a TEDS sensor and a matrix switch technology and a test method thereof. The test process of the test system comprises the following steps that (1) sensor TEDS information is read; (2) a conditioning module group is automatically configured; (3) automatic switching of channels is acquired; (4) sensor data are nonlinearly corrected; and (5) the data are parsed. The detection process is simple without artificial input of the sensor information or artificial replacement of the conditioning module and switching of the test channels so that detection efficiency is greatly enhanced. The intelligent test system is suitable for automatic conditioning and automatic testing of sensor output signals after intelligent reconstruction.

The invention provides a digital projector gray nonlinearity correction method, a storage medium and a projection system. The method comprises the following steps: generating an ideal grayscale image sequence by using a computer, collecting grayscale images by using a camera, solving an actual grayscale mean value Ik by using N groups of actual grayscale images, drawing a grayscale mean value curve comprising a linear part and a nonlinear part, and fitting the grayscale mean value curve to obtain a mapping relation between an ideal projection grayscale and a corrected ideal grayscale, obtaining a value table of actual gray under different current values, establishing a two-dimensional corrected ideal gray correction lookup table taking the ideal gray before current correction as a variable, and generating a sine curve by using the corrected ideal gray value and projecting the sine curve. According to the method, nonlinear correction can be directly carried out on the projection image of the projector, and the method is also suitable for changing the brightness of the projector, so that the accuracy of collecting the gray scale of the stripe image is improved, and the solving accuracy of phase information is greatly improved.

The embodiment of the invention relates to a mobile data calibration method and device, electronic equipment and a storage medium. The method comprises the following steps: receiving historical mobiledata and historical positioning data acquired by a measurement terminal in a historical time period, wherein the historical mobile data comprises historical IMU data collected by the measurement terminal; fitting the historical movement data and the historical positioning data to obtain a nonlinear calibration function after fitting; sending the fitted nonlinear calibration function to a terminalto be calibrated, wherein the fitted nonlinear calibration function is used for indicating the to-be-calibrated terminal to calibrate initial mobile data acquired by the to-be-calibrated terminal byusing the fitted nonlinear calibration function, so as to obtain calibrated mobile data and the initial mobile data comprises initial IMU data of the terminal to be calibrated. By adopting the method,the calculation complexity can be reduced, and the calibration cost can be saved.

The invention discloses a design scheme for a high-precision multichannel TDC based on a tap delay line. According to the invention, a secondary delay averaging structure, a tap timing sequence testing method, a compensation counting framework and a hybrid nonlinear calibration technology are provided for improving the linearity of the TDC and overcoming the phenomena of bubbles and missing-codesfor the first time, and the linearity of the TDC is remarkably improved by correcting accumulated nonlinearity and bin-width errors. Multi-channel design is achieved on platforms such as an FPGA and an ASIC while low logic resource consumption is kept. On an FPGA chip with the wavelength of 20 nm, time resolution can reach 5 picoseconds, and the linearity is remarkably improved compared with a traditional design. A 96-channel TDC array is realized on a single chip. According to the method, the nonlinear problem of limiting TDC measurement performance is solved, multi-channel design is realizedthrough multiple innovative methods, and the application value of the TDC is greatly improved.

The invention relates to a nonlinear function generator, a function transformer and a general nonlinear corrector, belonging to the technical fields of signal transformation and automatic control and measurement. The nonlinear function generator has the following types: an easy type and a synthetic type, inverted and inphase broken line types, inverted and inphase triangular wave synthesis types and a sine-wave synthesis type, and the like. The function transformer comprises the nonlinear function generator and an input and output gain controller which adopts a bipolar adjustable-gain amplifier, the nonlinear corrector has three types, i.e. a direct feed type, a feedback type and a combined type and comprises a weighted combiner, the function transformer and an output synthesizer, the general nonlinear corrector comprises a zero-bit adjustment circuit and the nonlinear corrector, and a (general) nonlinear corrector of a high impedance type adopts the (general) nonlinear corrector of a pre-voltage follower.

The present invention discloses a nonlinear calibration system and method of a photoelectric detector. The nonlinear calibration system comprises a transmission-reception separating device comprising a light source port, a reception port and a detection port; a light source device connected with the light source port; a reception light path connected with the reception port; and a detection light path connected with the detection port; The detection light path comprises the photoelectric detector, the light source device generates the signal light, and the transmission-reception separating device emits at least part of the signal light via the reception port, receives the echo signals returned by the emergent signal light at different distances via the reception port, and outputs the echo signals via the detection port. The detection light path obtains the echo signals via the photoelectric detector and records the echo signals, the echo signals are used to calculate the calibration factors of the photoelectric detector, and the nonlinear calibration is carried out on the photoelectric detector via the calibration factors. According to the technical scheme of the present invention, the nonlinear response of the photoelectric detector can be calibrated rapidly and conveniently and at high precision.