328results about How to "The calibration result is accurate" patented technology

A "coupled phase model" is used to characterize the motion induced by a sound wave of a particle relative to its dispersion medium. A Kuvabara cell model is used to describe the hydrodynamic effects, whereas a Shilov-Zharkikh cell model is used to characterize electrokinetic effects. A different approach for interpreting the experimental data is described in which the electroacoustic sensor is treated as a transmission line with various energy losses due to the reflection and sound attenuation. The experimental output is also expressed as a loss, namely the ratio of the Colloid Vibration Current to the gradient in the acoustic pressure, and is computed by subtracting all other known losses from the total loss of the electroacoustic sensor. These other energy losses can be either calculated or measured directly using reflected pulses.

The invention relates to a wide-baseline visible light camera pose estimation method. The method includes the steps that firstly, the Zhang calibration method is used, and internal references of cameras are calibrated through a plane calibration board; eight datum points on a landing runway are selected in a public visual field region of the cameras and world coordinates of the datum points are accurately measured off line through a total station; in the calibration process, cooperation identification lamps are placed in the positions of the datum points and the poses of the cameras are accurately calculated through detection of the cooperation identification lamps. According to the method, the complex natural scene characteristic of an unmanned aerial vehicle landing scene and the physical light sensing characteristic of the cameras are considered, and glare flashlights are designed and used as the cooperation identification lamps of the visible light cameras; the eight datum points are arranged on the landing runway and space coordinates of the datum points are measured through the total station according to space accuracy at a 10 <-6> m level. According to the method, a calibration result is accurate and a re-projection error on an image is below 0.5 pixel.

The invention discloses a fisheye calibration method and a device, which can be used for calibrating most of camera lenses, and are accurate in calibration result, simple in operation and high in efficiency. The technical scheme is that the method comprises the following steps of: establishing a half-unit spherical model, and establishing a fisheye imaging relationship on a unit spherical model; initializing internal parameters, wherein the internal parameters are parameters of a fisheye camera and have nothing to do with the external environment; calculating a homography matrix; initializingexternal parameters, wherein the external parameters are parameters between the fisheye camera and the external environment; and performing Levenberg-Marqardt (LM) iteration to minimize re-projectionerrors so as to obtain optimized internal parameters and external parameters.

The invention is suitable for the digital image processing field and provides a fish-eye lens correction method and device and a portable terminal. The method comprises the following steps: carrying out distortion correction on a fisheye image through an equidistant projection model to obtain an initial correction image, the image content of which is a calibration board; obtaining all angle pointsof the calibration board from the initial correction image, re-projecting angle point coordinates to the fisheye image to obtain rough angle point coordinate values of the calibration board in the fisheye image, and serving the angle points as feature points in the fisheye image; and carrying out iteration on the feature points in the fisheye image to obtain different parameter values within a preset parameter range, carrying out correction on the fish-eye lens through the equidistant projection model, and serving the parameter value obtained when the deviation amount is minimum as an accurate correction value of the fish-eye lens. The fish-eye lens correction method reduces preparation workload in the early stage, and is simple in operation process; a camera does not need to change position and angle; and the fish-eye lens correction method is wide in application range, does not need to set a lot of parameters, is simple to calculate, and meanwhile, realizes an accurate fisheye correction effect.

The invention belongs to the field of industrial robot calibration and discloses a method of calibrating a six-dimensional force sensor at the tail end of an industrial robot. The method comprises thefollowing steps of (a) in the measurement process of the six-dimensional force sensor, constructing a relational expression of a force, a torque and displacement measured by the sensor and a relational expression of zero values of the force and the torque on the sensor and a mass center of a load tool; (b) acquiring data of the forces and the torques measured by the six-dimensional force sensor under multiple postures, and performing calculation with a least square method to obtain the zero values of the force and the torque of the six-dimensional sensor; (c) constructing a relational expression about the gravity of the load tool and performing calculation; and (d) constructing a relational expression about installation angles of a sensor coordinate system and a tail end flange coordinatesystem along a Z axis and performing calculation. By adopting the method, the calibration time is shortened, and the measurement precision is improved after a calibration result is compensated.

The invention relates to a global calibration method for a vision-guided camera of a laser tracker. The method comprises the following steps: establishing a camera coordinate system, an image coordinate system, a laser tracker coordinate system and a target coordinate system; projecting a laser beam onto a plane target, and forming an image on the vision-guided camera, and repeatedly moving a target to obtain the linear equation of the laser beam in the camera coordinate system; obtaining laser tracker motion parameters, namely obtaining the linear equation of the laser beam in the laser tracker coordinate system; after the equations of multiple laser beams are obtained, obtaining a conversion relation between the camera coordinate system and the laser tracker coordinate system. The global calibration method disclosed by the invention is simple in operation, and can complete calibration by using one plane target, so that the speed of the global calibration is improved, and errors because calibration objects are repeatedly measured by a spherical reflector are avoided, so that calibration results are more accurate.

The invention relates to a gamma curve correction method, which comprises the following steps: selecting at least two different gray scales as characteristic gray scales in the whole gray scale rangeof a color image of a display panel. The sub-pixel information of the feature gray scale is measured to obtain the red sub-pixel information, the green sub-pixel information and the blue sub-pixel information of the feature gray scale. Then, the red sub-pixel information, green sub-pixel information and blue sub-pixel information of other gray scales except the characteristic gray scale are calculated by interpolation method. Combined with the formula of look-up table, the corresponding look-up tables of red sub-pixel, green sub-pixel and blue sub-pixel of each gray scale are obtained by recursive method. Storing a respective look-up table into a memory corresponding to the gamma curve to obtain a corrected gamma curve; Test the calibrated gamma curve and compare it with the target gamma curve. If it meets the requirements of the product specification, the calibration process is finished. The calibration method shortens the calibration time, improves the production efficiency and product pass rate of the panel, and the calibration result is accurate.

The invention discloses an external parameter calibration method used when a camera and a two-dimensional laser range finder are used in a combined mode and relates to three-dimensional information image processing of objects. According to the external parameter calibration method used when the camera and the two-dimensional laser range finder are used in the combined mode, a foldable calibration plate is used for achieving external parameter calibration when the camera and the two-dimensional laser range finder are used in the combined mode, the foldable calibration plate is a long plane which is formed by splicing small rectangular black planes and small rectangular white planes alternately and can be unfolded and folded, the foldable calibration plate is unfolded when used, and the unfolding angle can be adjusted freely; calibration of internal parameter of the camera is achieved by means of a Matlab camera calibration tool box; a camera and two-dimensional laser range finder system is established; the foldable calibration plate is placed, and calibration is completed under the condition that the number of times of information acquisition of a system is smallest; image information and two-dimensional information are acquired and processed by the camera and the two-dimensional laser range finder respectively; processed camera information and processed two-dimensional laser range finder information are matched in a one-to-one mode for combined calibration; a calibration result is optimized by means of the Levenberg-Marquardt algorithm, and then calibration is completed.

The invention discloses a calibration method for a microlens light field camera. The method comprises steps: based on the microlens light field camera, a white image and a target image are acquired; the microlens projection center position is detected on the white image; according to the microlens projection center position, the target image is decoded to obtain 4D light field data; a center sub-aperture image is generated by the 4D light field data, and corner points are detected; according to the corner point positions detected on the center sub-aperture image, sub images possibly containingthe corner points on the target image are selected; on the selected sub images, the corner points are detected; based on a corner point set detected on the center sub-aperture image, simplified modelinitial parameters are solved; based on a corner point set detected on the selected sub images, non-distorted model parameters are estimated; and with the non-distorted model parameters as initial values and based on the corner point set detected on the selected sub images, model parameters considering distortion are further estimated. The calibration method can estimate inner and outer parameters of the light field camera at the same time, functions are comprehensive, the result is accurate, and the efficiency is high.

The invention relates to a camera spatial position relation calibration device in a multi-camera photographing measurement system. The calibration device comprises a target plane, a plurality of cameras, a camera mounting rack and a PC (Personal Computer) machine. The target plane and the camera mounting rack are arranged at a set interval; the plurality of cameras are respectively arranged on the camera mounting rack; the PC machine is connected with the cameras; the target plane is provided with a plurality of square targets respectively consisting of four target points; the plurality of square targets are respectively and correspondingly positioned in view fields of the plurality of cameras; the PC machine controls the cameras to acquire images of the corresponding square targets, obtains a position of each target point in a camera coordinate system and calculates a spatial position relation between each two corresponding cameras according to a position relation between each two square targets. Compared with the prior art, the camera spatial position relation calibration device in the multi-camera photographing measurement system has the advantages of accurate calibration result, simplicity for operation, low cost and the like.

The invention belongs to the technical field of image processing, and particularly relates to a multi-point correction method for an infrared focal plane. The method comprises steps as follows: step 1, an infrared focal plane detector acquires images of different temperature black bodies at the working temperature in every other 5 DEG C and uses the images as background images; step 2, a shutter is started, a related parameter of a shutter image is acquired, and a shutter correction parameter is acquired with the following formula shown in the specification according to the background images, wherein delta O is the shutter correction parameter, the related parameter of the shutter image comprises the mean value Xs of a shutter image Xs and the shutter image, Bi is the i background image, Bi is the mean value of the background images, Ks is a gain correction parameter corresponding to the shutter image, and Ks is the mean value of the Ks; step 3, according to the shutter correction parameter delta O, a gain correction parameter K and a bias correction parameter Bj which correspond to an object image are introduced into the following formula shown in the specification for two-point correction, and a corrected image Y is calculated, wherein X is the to-be-corrected image, Y is the corrected image, delta O is the shutter correction parameter, Bj is the j background image, and K is the gain correction image.

The invention discloses a point-by-point correction method for an LED display screen, and belongs to the field of LED display screen correction, and the method comprises the steps: S100, obtaining thebrightness value of each LED single lamp on an LED display screen; S200, calculating to obtain a standard brightness value of each LED single lamp based on a gradient descent method according to thebrightness values of all the LED single lamps; S300, calculating a correction coefficient of each LED single lamp according to the brightness value of each LED single lamp and the standard brightnessvalue; and S400, correcting the LED display screen according to the correction coefficient of each LED single lamp. According to the invention, the brightness difference between the LED single lamps can be well eliminated, the uniformity of the LED display screen is remarkably improved, and the display quality is improved.

The invention discloses a method for calibrating downlink channel gain. The method comprises the following steps of: acquiring a forward power value through forward power detection (OPD); calculating a power difference value between the forward power value and a target power value; calculating downlink channel gain adjustment according to the power difference value when absolute value of the power difference value is greater than or equal to a preset calibration threshold value; and calibrating current downlink channel gain according to the downlink channel gain adjustment. The invention alsodiscloses a device for calibrating the downlink channel gain. By adopting the method and device for calibrating the downlink channel gain, the downlink channel gain can be quickly and accurately calibrated.

The invention discloses a video space-time super-resolution method and device based on improved deformable convolution correction. The method comprises the following steps: constructing a video space-time super-resolution network comprising a feature extraction module, an inter-frame correction module and an image reconstruction module; performing network parameter optimization on the video space-time super-resolution for later use; during application, using the feature extraction module for extracting feature maps from input low-fraction adjacent video frames, and using the inter-frame correction module for carrying out correction processing according to the feature maps corresponding to the adjacent video frames to synthesize an intermediate frame feature map; and performing inter-frame and intra-frame feature extraction on the input intermediate frame feature map and the feature map corresponding to the adjacent video frame by using an image reconstruction module, and reconstructing and outputting a high-resolution and high-frame-rate image sequence. By improving a deformable convolution mode and introducing explicit optical flow estimation, an attention network and other skills, an inter-frame correction network is enabled to be better competent for a video space-time super-resolution task, and a restoration effect is greatly improved.

The invention relates to a full-solid millimeter wave cloud radar calibration probe system and method. The full-solid millimeter wave cloud radar calibration probe system comprises a control module generating control signals, a signal generation module, a millimeter wave receiving module, a full-solid emitter, an antenna feeder sub-system, a signal processing sub-system and a master control module, wherein the signal generation module generates one test signal and two emitting excitation signals according to the control signals within the same period in a set time sequence, the millimeter wave receiving module carries out amplification and down-conversion processing on received test signals and target probe echo signals, the full-solid emitter generates probe signals according to the two emitting excitation signals, the antenna feeder sub-system is used for radiating the probe signals to the space and the target probe echo signals, the signal processing sub-system is used for processing the test signals and the target probe echo signals, and the maser control module is used for displaying and recording a received signal processing result. The full-solid millimeter wave cloud radar calibration probe system generates the test signals and emitting probe excitation signals within the same period and realizes real-time on-line calibration of a receiver. Two emitting excitation pulses work alternatively, the power of radar probe is improved, and meanwhile low-altitude blind area coverage is realized.

The embodiment of the invention discloses a radio-frequency power calibration method of a magnetic resonance imaging system. In the method, radio-frequency pulse amplitudes progressively increasing in a larger step length mode are first selected to undergo traversal scanning during traversal, FID signal values corresponding to the different radio-frequency pulse amplitudes are obtained, the step length is constantly decreased during traversal scanning of the next time, a traversal scanning range is constantly narrowed by determining an initial value and an end point value for traversal again, accordingly the radio-frequency pulse amplitudes corresponding to 90-degree turning angles are quickly and accurately determined, and further a linear relation curve about the turning angles and the radio-frequency pulse amplitudes is obtained according to the 90-degree turning angles and the radio-frequency pulse amplitudes. The radio-frequency power calibration method can quickly and effectively calibrate the radio-frequency power, conveniently provides more accurate calibration structures for different subjects and further obtains better imaging quality.

A method includes acquiring first and second images that are captured by imaging a first real marker with a camera when the camera is respectively at a first and second positions with respect to the first real marker, deriving a motion of an inertial sensor based on output of the inertial sensor when the camera moves from the first position to the second position, displaying a marker image corresponding to a second real marker on a display, acquiring a third image that is obtained by capturing the second real marker with the camera when a user perceives the marker image and the second real marker being aligned with each other, and deriving a first spatial relationship between the camera and the inertial sensor and a second spatial relationship between the camera and the display based at least on the first and second images, the motion, and the third image.

The invention discloses a space calibrating body and method based on a virtual ball. According to the space calibrating body and method based on the virtual ball, calibration is conducted in the form that a standard bar piece is separated from a base, a laser tracker is adopted to serve as measurement equipment, and a hard aluminum alloy plate is adopted by the base to serve as an installation platform of the standard bar piece. The space calibrating method based on the virtual ball comprises the steps that the space calibrating body which has three degrees of freedom is manufactured firstly, threads are machined at the two ends of the standard bar piece, one end of the standard bar piece is fixed to the hard aluminum alloy plate, the other end of the standard bar piece is used for fixing the body of the virtual ball, a regular octahedron with the top end cut off serves as the body of the virtual ball, a cone nest is machined on each face of the virtual ball, and then the virtual ball is calibrated with the laser tracker serving as the measurement equipment. The space calibrating body and method based on the virtual ball have the advantages that the precision is high, machining requirements for the standard piece are low, the number of needed sampling points is small when the space calibrating body and method are used, the calibrating efficiency is improved, and the sampling workload is greatly reduced and the calibrating efficiency is improved when an articulated type coordinate measuring machine is calibrated.

The invention relates to a multi-sensor arrangement device for temperature and humidity detection and calibration of a constant-temperature constant-humidity box, a stand column is arranged on a base,a supporting seat is arranged on the stand column in a penetrating mode, the supporting seat can slide up and down along the stand column, the supporting seat fixedly connected with the stand columnby a jackscrew, a plurality of rotating shafts are arranged on the supporting seat, one ends of cantilevers sleeve the rotating shafts, the cantilevers can rotate horizontally relative to the rotatingshafts, the cantilevers can be fixedly connected with the rotating shafts by jackscrews, the cantilevers are telescopic cantilevers, the other ends of the cantilevers are hinged to one ends of extension arms, the extension arms are telescopic extension arms, the other ends of the extension arms are hinged to one ends of connection blocks, the other ends of the connection blocks are hinged to sensor supports, and mounting holes used for mounting temperature sensors and humidity sensors are formed in the sensor supports; multi-layer multi-point arranged sensors can be arranged in the constant-temperature constant-humidity box at one time, the rapid arrangement of the sensors can be realized when the constant-temperature and constant-humidity box is calibrated, the calibration efficiency canbe effectively improved, the labor intensity is reduced, and the accurate calibration result is ensured.

The invention provides a robot hand-eye calibration method and device, electronic equipment and a system. The method comprises the steps that three-dimensional point cloud image information obtained through photographing of a three-dimensional camera is obtained, wherein the three-dimensional point cloud image information comprises three-dimensional point cloud information of at least three identification balls which are not completely located on the same straight line; first position data of the mass center of the identification balls in a camera coordinate system are calculated according tothe three-dimensional point cloud image information; second position data of the mass center of the identification balls in a robot base coordinate system are acquired; and a conversion matrix betweenthe camera coordinate system and the robot base coordinate system is calculated according to the first position data and the second position data. Calibration can be completed only by acquiring the image information once, so that hand-eye calibration of a robot can be completed quickly, the efficiency is high, the calibration result is accurate, and the requirement on the industrial skill of an operator is relatively low.

The invention relates to a calibration method for an oil-water relative permeability curve and an oil displacing efficiency. The calibration method comprises the following steps: 1), performing an indoor oil-water relative permeability experiment, combining basic parameters of the experiment so as to obtain experimental data of a water ratio, cumulative oil yield, cumulative water yield and the like at different sampling times, and drawing an oil-water relative permeability curve before calibration; 2), fitting the cumulative oil yield and the cumulative water yield by adopting a Zhang type water driving curve with wide adaptability, and solving recoverable reserves; 3), plugging the recoverable reserves and the basic parameters of the experiment into an expression of residual oil saturation, and solving the residual oil saturation; 4), according to the residual oil saturation and an exponential expression of a water phase relative permeability curve in the straight line form, solving water phase relative permeability corresponding to the residual oil saturation; 5), replacing the residual oil saturation and the water phase relative permeability corresponding to the residual oil saturation in the oil-water relative permeability curve before the calibration with the solved residual oil saturation and the solved water phase relative permeability corresponding to the solved residual oil saturation, so that an oil-water relative permeability curve after calibration is obtained; and 6), calibrating the oil displacing efficiency according to the solved residual oil saturation.

The invention relates to a vehicle-mounted camera self-calibration method and device and a vehicle driving method and device, and the method comprises the steps: starting the self-calibration of a vehicle-mounted camera, and enabling a vehicle with the vehicle-mounted camera to be in a driving state; in the running process of the vehicle, collecting information required by self-calibration of thevehicle-mounted camera through the vehicle-mounted camera; and self-calibrating the vehicle-mounted camera based on the acquired information. According to the embodiment of the invention, the self-calibration process of the vehicle-mounted camera can be conveniently completed in the actual use environment of the vehicle-mounted camera under the condition that the use of the vehicle is not influenced, the calibration result is accurate, the calibration efficiency is high, and the application range is wide.

The invention discloses a loading force value calibrating device suitable for a fatigue-testing machine, and the loading force value calibrating device comprises an air cylinder (1) provided with a piston (2), a data acquisition system (3), a high-precision force sensor I (4), a force sensor (6) and a fixture (7) used for clamping samples (8). The calibrating device also comprises a high-precision force sensor II (5), the high-precision force sensor I (4), the high-precision force sensor II (5) and the force sensor (6) are sequentially fixed between the piston (2) and the fixture (7), and thehigh-precision force sensor I (4) and the high-precision force sensor II (5) are both connected with the data acquisition system (3) through signals. The invention also provides a loading force valuecalibrating method carried out by the calibrating device. In the calibrating method, an acceleration value a does not need to be obtained, and errors brought by inertia force in calibration can be eliminated indirectly so as to achieve the result of accurate calibration.