39results about How to "Improve calibration results" patented technology

Provision is made of a semiconductor radiation source having a base body on which at least two LED chips are mounted, at least one chip of which is connected to a series resistor which can be adjusted. The LED chips (12, 14) are fitted to the base body (24) using a thermally conductive connection and at least one printed circuit board (30) which bears the series resistor (40, 42) is also mounted on the base body (24).

Disclosed is a bi-directional piston displacement type volumetric fluid flow rate delivery and metering system (calibration standard) and operational method for calibration of fluid flowmeters. The present invention provides reduced uncertainty of delivered volumetric fluid flow rate at meters under test relative to the uncertainty of volumetric fluid flow rate at meters under test provided by prior art bi-directional piston displacement type volumetric fluid flow rate standards given the same nominal cylinder diameters and working fluid and equal dimensional, timing and temperature measurement uncertainties by employing a plurality of metering pistons and cylinders to minimize the connecting volume piping between the metering piston cylinder outlet and meters under test, providing open access to one side of each metering piston to accomplish installation of temperature probes through the pistons into the working fluid and by operational method which minimizes the connecting volume to standard volume ratio.

Disclosed is a bi-directional piston displacement type volumetric fluid flow rate delivery and metering system (calibration standard) and operational method for calibration of fluid flowmeters. The present invention provides reduced uncertainty of delivered volumetric fluid flow rate at meters under test relative to the uncertainty of volumetric fluid flow rate at meters under test provided by prior art bi-directional piston displacement type volumetric fluid flow rate standards given the same nominal cylinder diameters and working fluid and equal dimensional, timing and temperature measurement uncertainties by employing a plurality of metering pistons and cylinders to minimize the connecting volume piping between the metering piston cylinder outlet and meters under test, providing open access to one side of each metering piston to accomplish installation of temperature probes through the pistons into the working fluid and by operational method which minimizes the connecting volume to standard volume ratio.

A camera calibration system for cameras of a vehicle includes a plurality of cameras disposed at a vehicle and having respective fields of view exterior of the vehicle, with the fields of view of two of the cameras overlapping. While the vehicle is moving, an image processor of a control processes image data captured by the two cameras to determine and track matching features in an overlapping region of the fields of view of the two cameras. The control, responsive to image processing of image data captured by the two cameras, determines motion of matching features and minimizes a cost function of the error in the matching of the features. The camera calibration system uses the determined minimized cost function to refine calibration results of the two cameras using a feedback loop.

The invention relates to an image postprocessing method for removing a metal artifact from a computed tomography (CT) image, which comprises the following steps of: converting an original CT image into a polar coordinate image from an orthogonal coordinate image; determining a metal projection region in the polar coordinate image; establishing a model in the polar coordinate image; performing model correction by adopting the model; correcting front and back projection errors brought into the model correction; and converting the polar coordinate image into the orthogonal coordinate image. According to a model establishing method provided by the invention, the good model can be established, and finally, a good correction result can be obtained; the errors brought in by front and back projection are corrected, so that the result after the correction is better, and the processing speed is ensured.

A test stand encompasses a dynamometer, which is supported to oscillate about a main axis, from which a lever arm extends perpendicularly. For calibrating a force-measuring device, which is coupled to the lever arm, provision is made for a pneumatic cylinder as reference force-generating device. The reference force can be measured by a load cell and can be applied to the lever arm via a yoke. The force-measuring device, which is to be calibrated, the pneumatic cylinder, the load cell, and the yoke are disposed on the same side of the dynamometer and act on the same lever arm.

Presented herein are systems and methods that provide for calibration and / or testing of liquid scintillation counters (LSCs) using an electronic test source. In certain embodiments, the electronic test source described herein provides for emission of emulated radioactive event test pulses that emulate light pulses produced by a scintillator as a result of radioactive decay of a variety of different kinds of radioactive emitters (e.g., beta, alpha, and gamma emitters). Additionally, in certain embodiments, the systems and methods described herein provide for the emission of emulated background light (e.g., luminescence and after-pulses) from the electronic test source. The emulated radioactive event test pulses and, optionally, emulated background light can be used for the calibration and / or testing of LSCs, in place of hazardous radioactive material and / or volatile chemicals. Accordingly, the systems and methods described herein dramatically improve the calibration and / or testing of liquid scintillation counters.

The invention discloses a camera self-calibration method based on IOS-PSO (Internetwork Operating System-Particle Swarm Optimization). The method is relatively simple in algorithm, high in efficiency and high in optimizing result precision. The method mainly comprises three steps: S1, establishing an internal parameter-based cost function of a camera; S2, performing IOS-PSO on the cost function; and S3, limiting a rule for an IOS-PSO search result. The method comprises the following specific steps: acquiring four pictures of different angles of the same scenario; extracting and matching image feature points; solving three basis matrixes F by using the matched points and adopting an RANSAC (Random Sample Consensus) method, and then performing SVD (singular value decomposition) on the basis matrixes to construct the cost function as a fitness function of particle swarm optimization; dividing a set initial search interval, and setting a research rule according to the optimal value; taking five unknown internal parameters fu, fv, u0, v0 and s to be calibrated in the camera as particle elements of a particle swarm; performing IOS-PSO search; and if the search result accords with the search rule, selecting the final search result, otherwise, searching again. Contrast experiments of four algorithms verify that the calibration result of the method is accurate, stable and efficient.

The invention relates to a variety of oil pressure channel calibration devices, including an oil pressure generating unit and an oil pressure measurement and control unit; the oil pressure generating unit is used to generate pressure in the oil channel, including a pre-charging pump and a hand pump. The pump is used to decompress the oil passage and fill the oil. The hand pump is used to boost the pressure in the oil passage and the meter to be tested. By adjusting the fine-tuning valve, the pressure in the oil passage can reach the required pressure value. The check valve releases the pressure and checks the pressure. The oil pressure measurement and control unit is used to measure and control the pressure in the oil channel, including the central control module and the data acquisition module. The central control module is a single-chip microcomputer, and the pressure input and The preprocessing module receives the data transmitted by the first pressure output terminal and the second pressure output terminal and preprocesses the data, and transmits the preprocessed data to the data acquisition module, which is connected to the central control module, and the processed The data is transmitted to the central control module and displayed on the display module.

An endless belt aplanatic spherical surface lens, the characteristic is: divides the two spherical surfaces the spherical surface simple lens into N endless belts with different caliber, every endless belt processes translation relative the base spherical surface along the light axis on the same spherical surface, the translation distance is descending in turn from smaller endless belt to the bigger endless belt, confirms the value of N, the caliber of every endless belt and the translation quantity of every endless belt on the axis direction according to the aplanatic requirement of the practice application. The advantages of the invention are: for the light paralleling with the light axis can get the better aplanatic revise result; the surface structure of the lens is sample.

The embodiment of the present application discloses a method for triggering recalibration and related devices, which are applied to electronic equipment. The method includes: selecting the target verification point of the display screen of the electronic equipment; detecting the algorithm output point where the user looks at the display screen, and the algorithm output point is The gaze position of the user's eyes on the display screen calculated by the electronic device; determine whether the algorithm output point is corrected according to the target verification point and the algorithm output point; if not, trigger re-calibration. The embodiment of the present application is beneficial to improve the correction effect and improve the gaze accuracy.

The invention discloses a method for extracting atmospheric density based on the SWARM-C satellite. The accelerometer data and the GPS track data of the SWARM-C satellite are obtained first, and then resampling and coordinate system conversion are performed on it; The spike signal and step signal; after the data is checked, the accelerometer data is corrected, and the deviation coefficient, proportional coefficient and temperature coefficient in the correction formula are estimated by the generalized least square method, and the corrected accelerometer data is obtained; then the satellite Model the radiation pressure of light received on its orbit, calculate the acceleration caused by the light radiation pressure, subtract the acceleration caused by the light radiation pressure from the corrected accelerometer data, and obtain the atmospheric drag acceleration; finally calculate the satellite in The product of the damping coefficient and the effective area of ​​its orbital operation is used to calculate the atmospheric density near the satellite orbit based on the product of the atmospheric drag acceleration and the product of the damping coefficient and the effective area.

The invention discloses an adaptive brightness unevenness variation correction method based on a Retinex variation framework and aims to provide an adaptive correction method to realize no logarithm transformation, eliminate a non-uniform image brightness phenomenon and effectively keep image colors and the detailed information. The method is characterized in that an optical imaging detection system is utilized to acquire an uneven degeneration image as an observation image; an adaptive weight function is constructed according to space characteristics of the observation image; an original Retinex theory is utilized to construct a variation correction model, total variation regularization constraint intensities of a reflection component in the variation correction model at different pixel points are adaptively controlled through the weight function, and a mean value of the reflection component is employed to approximate gray mean constraints to prevent local overexposure; a split Bregman iteration method and an alternative minimization method are then utilized to solve the variation correction model to acquire an illumination component and the reflection component, and the reflection component is lastly rounded to acquire a correction image.

The present application discloses a measurement method, device, system and medium based on binocular microscopic vision. Constraint relationship, perform image correction to obtain the left and right images; down-sample the left and right images, perform stereo matching and matching point propagation on the pixels in the sampled image of the corresponding layer with the smallest resolution in the obtained left sampled image set, and perform layer-by-layer sampling and Stereo matching update and interpolation processing to obtain dense disparity results; then measure the object to be tested according to camera parameters and dense disparity results. The embodiment of the present application solves the problem of inapplicability and low accuracy of the measurement method on the macro scale in the prior art to the micro scale, and the measurement method provided is very suitable for binocular measurement in the micro scene, and can obtain good accuracy and precision of microscopic measurements.

The invention discloses an inverse dispersion method for eliminating a Gibbs annular artifact of a magnetic resonance image. The method comprises the following steps of: reading an MR artifact image acquired through magnetic resonance imaging; calculating the gradient of each pixel from the image data and inversely diffusing the grey values of all pixels along the gradient direction; forming limiting conditions of grey value diffusion so as to make the whole diffusion process capable of adaptively adjusting the diffusion speed and to guarantee the stability of the whole diffusion process; obtaining the directional diffuseness of a diffusion equation which progresses the grey value; and updating the grey values of the pixels to acquire the corrected MR image. A high-quality image can be acquired by performing data correction on the artifact generated by cutting of the k space data.

The invention provides a projection system and a projection method thereof. The projection system comprises a projection device, a memory, an image acquisition device and a processor, wherein the memory records a corresponding relationship between a plurality of test templates and a plurality of groups of image acquisition parameters. The projection device projects a plurality of test templates towards the projection area, and the processor controls the image acquisition device to shoot the projection area with a plurality of groups of image acquisition parameters according to the corresponding relationship recorded in the memory so as to obtain a plurality of first reference images corresponding to the plurality of test templates. The projection device is controlled to project a projection image according to the plurality of test templates and the plurality of corresponding first reference images. According to the projection system and the projection method thereof provided by the invention, the camera can shoot clear test template images when the projector continuously projects a plurality of test templates, and the accuracy of automatic correction of the projector is improved.

The present invention is a multi-surface estimation interval type II fuzzy clustering MRI brain image segmentation method. The method first multiplies a plurality of base surfaces by weights to fit the offset field surface, and introduces the objective function as a multiplier item, through iteration The solution makes the fitted offset field surface gradually approach the real offset field; then, the method is upgraded to the interval type II fuzzy field, so that the method can better deal with the fuzzy boundary problem in the iterative process, and improve the ability of the method to deal with fuzzy problems ; Then consider the pixel information of the neighborhood space and add it to the objective function to increase the neighborhood space information. The method of the invention improves the ability to deal with blur problems, reasonably utilizes the neighborhood information, obtains obvious improvements in the offset field correction and segmentation results obtained on the magnetic resonance image, and has broad market prospects and application value.