2182 results about "Calibration result" patented technology

The invention discloses a binocular stereo vision based intelligent three-dimensional human face rebuilding method and a system; the method comprises: preprocessing operations including image normalization, brightness normalization and image correction are carried out to a human face image; a human face area in the human face image which is preprocessed is obtained and human face characteristic points are extracted; the object is rebuilt by projection matrix, so as to obtain internal and external parameters of a vidicon; based on the human face characteristic points, gray level cross-correlation matching operators are expanded to color information, and a parallax image generated by stereo matching is calculated according to information including polar line restraining, human face area restraining and human face geometric conditions; a three-dimensional coordinate of a human face spatial hashing point cloud is calculated according to the vidicon calibration result and the parallax image generated by stereo matching, so as to generate a three-dimensional human face model. By adopting the steps, more smooth and vivid three-dimensional human face model is rebuilt in the invention.

The invention discloses an automatic calibration apparatus for a robot tool coordinate system based on laser tracking measurement and a method thereof, wherein the apparatus comprises a robot, a target flange, target installing holes, a laser tracker, a tool and a host computer; the robot is provided with the target flange and the tool; the target flange is provided with six target installing holes; and the external side of the robot is provided with the laser tracker and the host computer. According to the method of the invention, the robot tool coordinate system is calibrated by matching, analyzing and calculating the position relations of three to six targets in a robot end wrist coordinate system and in the robot tool coordinate system. The apparatus and the method provided by the present invention have the advantages that the robot tool coordinate system can be automatically calibrated; calibration operation is simple and is high in precision and high efficiency; calibration results are reliable; and digitalized modeling and digitalized calibrating are realized and the tool possesses versatility when being replaced.

The invention provides a calibration method for a binocular stereo measurement system, and belongs to the technical field of measurement and test. The invention adopts a plane calibrating board having a characteristic dot array with an accurate given distance between the centers of two characteristic dots; the calibrating board is shot from more than three angles; initial values of the intrinsic and extrinsic parameters of two cameras are solved by using the linear method under a pinhole model; the distortion effect is considered; the intrinsic and extrinsic parameters of the two cameras are taken as optimization variables for a first optimization; the space coordinates of the centers of the characteristic dots on the calibrating board are taken as optimization variables for a second optimization; the translation vector between the cameras is scaled to the ratio of the calculated distance to the given accurate distance, thus getting a calibration result of the parameters; the result of the second optimization is got by using the intrinsic parameters and the relative attitude parameters of the two cameras. Considering the influence of the geometrical errors of the calibrating board, the method reduces the manufacturing, measurement and calibration requirement of the calibrating board and gets calibration result of high precision.

The invention discloses a method for measuring object deformation in real time, which comprises the following steps: arranging and adjusting measuring equipment, namely symmetrically arranging two cameras and corresponding LED illumination lamps above a measured object, and making optical axes of the two cameras intersected in a distance of 1 meter in front of the cameras; then calibrating the cameras, namely tightly sticking mark points to the surface of an object to be measured according to the size and shape of the measured object and the measurement requirement; next, placing the measured object stuck with the mark points under the two cameras in about 1 meter or moving the whole measuring equipment to make the measured object enter a measurement range and enable each camera to acquire the mark points on the surface of the measured object, starting the two cameras to shoot sequence images, and acquiring digital images; then identifying and positioning the images; reversely solving a projection matrix according to the calibration result of the cameras, and combining image coordinates of the solved mark points on the surface of the measured object on the images of the two cameras to reconstruct a three-dimensional coordinate of the mark points; and finally, carrying out deformation analysis and calculation for the mark points on the surface of the measured object.

The invention discloses a face recognition method and system, in particular relates to a face recognition model training method and system. The face recognition method comprises the following steps: every user for recognition is trained and a face recognition model is obtained; within the set face posture range, the face image with structure light coding and the face image without structure light coding of the present user waiting for recognition are collected simultaneously; a face range image is obtained based on the face image with structure light coding, and a face gray image is obtained based on the face image without structure light coding; the face gray image is used for calibration, and face pre-treatment is conducted for the face gray image and the face range image based on the calibration results; the characteristics of pretreated face range image and face gray image are calculated respectively; the characteristics are input to the face recognition model to recognize faces and output face recognition results. The technical proposal provided by the invention can reduce the interference of light to face recognition and reduce costs simultaneously.

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 global calibration method based on a binocular visual system and a laser tracker measurement system. Firstly a rigid stereoscopic target of which the A side is provided withbinocular visual system circular mark points and the B side is provided with laser tracker measurement target balls is manufactured; then the A side coordinate system and the B side coordinate systemof the stereoscopic target are established; the transformation relation between the A side coordinate system of the stereoscopic target and the left camera coordinate system of the binocular visual system and the transformation relation between the B side coordinate system of the stereoscopic target and the laser tracker world coordinate system are solved; the transformation relation between the Aside coordinate system and the B side coordinate system is solved according to the transformation relation solved in the last step; and finally the transformation relation between the left camera coordinate system of the global calibration binocular visual system and the laser tracker world coordinate system is solved. The difficulty of directly processing and maintaining the high-precision stereoscopic target can be reduced so that the measurement error caused by direct measurement can be solved and the more accurate calibration result can be acquired.

A method for calibrating (700) an antenna array comprises a plurality of antenna elements coupled to a plurality of respective receive paths in a wireless communication system. The method comprises, in receive mode, applying a test signal to an individual single receive path (715) of the plurality of receive paths; and feeding back the test signal via a switched coupler network. The method further comprises running a receive calibration measurement routine to determine at least one measurement value used to calibrate the individual signal receive path and waiting for at least one converged measurement value; and extracting (720) the converged measurement value for at least one individual receive path. The steps of applying, running, extracting for a next individual single receive path are repeated until the calibration routine has completed (725). The method further comprises selecting a converged measurement value of at least one individual receive path from a plurality of receive paths (730) to form a reference receiver calibration result (730); normalizing a plurality of at least one measurement values of the plurality of receive paths using the reference receiver calibration result (730); and applying a normalized value to at least one of the plurality of receive paths.

The invention discloses a large-scale MIMO (Multiple Input Multiple Output) antenna array far field calibration system. The calibration accuracy of a wave beam direction error caused by an array element position error and an amplitude phase error in an antenna array under test can be effectively increased by the calibration system. The calibration system is implemented by the following technical scheme: a server control device controls the relative position between the antenna array under test and a beacon antenna, and changes a wave beam incident angle from a transmitting beacon antenna to areceiving antenna array under test or a wave beam departure angle from a transmitting antenna array under test to a receiving beacon antenna; a phased array wave control device controls all phase shifters, attenuators, switches and digital weighting of a feed network of the antenna array under test; a data transmitting and acquiring device controls digital signals transmitted by the transmitting antenna array under test and the transmitting beacon antenna, and acquires digital signals received by the receiving antenna array under test and the receiving beacon antenna; and the array element positioning error and the amplitude phase error of the antenna array under test are calculated on the basis of a digital domain signal processing algorithm, and a calibration result of the antenna arrayunder test is output.

Disclosed herein is a 3D urban modeling apparatus and method. The 3D urban modeling apparatus includes a calibration unit for calibrating data about a translation and a rotation of at least one capturing device at a time that input aerial images and terrestrial images were captured. A building model generation unit generates at least one 3D building model based on the aerial images and the terrestrial images to which results of the calibration have been applied. A terrain model generation unit generates a 3D terrain model by converting an input digital elevation model into a 3D mesh. A texture extraction unit extracts textures related to the building model and the terrain model from the aerial images and the terrestrial images. A model matching unit generates a 3D urban model by matching the building model with the terrain model, which are based on the textures, with each other.

The invention discloses a method and a device for testing a radio frequency index and a wireless index of an active antenna system. A probe-type test hood based on a near field coupling mode is adopted to test the radio frequency index of the tested active antenna system. The method comprises test hood single body calibration, test hood environment calibration, radio frequency index test, putting the tested active antenna system into the test hood, wherein the test environment is the same as the calibration environment, and carrying out radio frequency test on the tested active antenna system through a radio frequency port of a test probe after compensating the test environment according to the calibrated calibration result. The invention provides the comprehensive testing method at the same time. A space radio frequency (OTA) test is respectively adopted to test spatial characteristic of the active antenna system; and the near field coupling mode is adopted to test the radio frequency index of the active antenna system. The advantages of two testing methods are fully combined, and the defects and problems of the two testing methods are overcome and solved, thereby optimizing the test efficiency and the test cost.

The invention relates to a planar constraint based robot calibration method. The planar constraint based robot calibration method specifically comprises the following steps of utilizing a DH and MDH combination method to establish a robot kinematic model, establishing a robot tail end position error model based on a differential conversion principle, establishing a position calibration model of a robot based on planar constraint, setting a calibration block pose position, demonstrating and recording the robot tail end theoretical pose position, calibrating motion parameters of a robot, utilizing a calibration result to perform comparison, and performing re-calibration if the accuracy requirement is not met. The planar constraint based robot calibration method has the advantages of being simple, practical, efficient and low in cost, expensive measurement instruments are not needed, calibration cost is reduced, and positioning accuracy is improved.

The invention provides an automatic calibration method for a video monitoring system. The video monitoring system comprises a wide-angled camera namely a gun-type camera and a PTZ camera namely a ball-type camera, wherein the wide-angled camera is used for shooting a wide angled picture namely a gun-type camera picture in a large-scale field of vision, and the PTZ camera is used for shooting a local enlarged picture namely a ball-type camera picture in the large-scale field of vision. The automatic calibration method comprises a step of rough calibration and a step of specific calibration, wherein the rough calibration is that a mapping relation between a gun-type camera picture coordinate and a ball-type camera picture coordinate and a mapping relation between the ball-type camera picture coordinate and a ball-type physics coordinate are utilized to obtain a mapping relation between the gun-type camera picture and the ball-type physics coordinate, and the specific calibration is that a rough calibration result is rectified by utilizing of a ball-type light center picture coordinate. By means of the automatic calibration method, people can be liberated from a complex calibration operation, and automation of a procedure is achieved. The whole calibration time is controlled within 90s equal to the calibration time of a skillful operator, and the calibration precision is even superior to that of manual calibration.

The embodiment of the invention relates to a calibration method for data of a laser radar and a camera, which comprises three parts, namely automatic data acquisition of the laser radar and the camera, external parameter calibration of the laser radar and the camera and external parameter calibration result evaluation, and the method is simple in process, easy to operate and high in efficiency; for external parameter calibration of a low-wire-harness laser radar and a camera, relatively high external parameter calibration precision is achieved; external parameter calibration results are good in consistency, and the requirements of automatic driving vehicle calibration task process, high efficiency, good consistency, high precision and the like can be met.

The invention provides a fundus OCT imaging method utilizing three-dimensional imaging of binocular stereo vision and a system thereof with the purpose of solving the problem that three-dimensional correction of phase positions, spatial positions and angles of OCT signals is not precise. The method comprises following steps of: synchronously collecting a binocular stereo vision imaging system and a fundus OCT system; utilizing a self-calibration result of the binocular stereo vision imaging system and acquiring a rotation matrix ROI and a translation vector TOI between an OCT coordinate system and an coordinate system for binocular stereo vision and re-establishing three-dimensional coordinates of bifurcation points of retina surface vessels; acquiring a rotation matrix RIE and a translation vector TIE from the coordinate system for binocular stereo vision to a coordinate system of human eyes; extracting a retina B scanning image; utilizing the rotation matrix ROI and the translation vector TOI in order to achieve conversion of the B scanning image from the OCT coordinate system to the coordinate system for binocular stereo vision; utilizing the rotation matrix RIE and the translation vector TIE in order to realize conversion of the B scanning image from the coordinate system for binocular stereo vision to the coordinate system of human eyes; obtaining a three-dimensional OCT image with uniform spatial distribution by interpolation of the converted B scanning image in the coordinate system of human eyes.

The invention discloses a twin port calibration method for a nonlinearity vector network analyzer, relates to the technical field of microwave millimeter wave measurement and solves the problems that twin port calibration technology of existing nonlinearity vector network analyzers is single, and self-checking of a calibration result is difficult. Two ports of the nonlinearity vector network analyzer are utilized to perform open circuit, short circuit, loading, power, phase position and through calibrations respectively to obtain a nominal value and an actual measured value of a calibrated workpiece, eight error models are determined according to all obtained coefficients, and the calibration for the nonlinearity vector network analyzer is achieved. The twin port calibration method for the nonlinearity vector network analyzer is applicable to signal analysis and the most in-depth analysis for characteristics of non-linear devices.

The invention relates to a novel lane line deviation detection method and a novel lane line deviation detection device. The method comprises the following steps of: detecting a lane line by using a plurality of cameras arranged on a vehicle body, and simultaneously, acquiring the running speed of a vehicle by using a vehicle speed sensor; acquiring state information of the vehicle in a lane according to calibration results of the cameras arranged on the side of the vehicle body and the positions of the lane line in images; and performing lane deviation evaluation, and judging whether the vehicle can deviate from the lane. The device comprises a plurality of cameras, the vehicle speed sensor and a processor, wherein a plurality of cameras are arranged on the vehicle body; and a plurality of cameras and the vehicle speed sensor are respectively connected with the processor. Compared with the prior art, the method and the device have the advantages that the method and the device are wide in application range, the lane line detection accuracy and the vehicle state detection accuracy are high, and the real-time performance is high.

The invention discloses a channel sandstone reservoir identification method. The method includes: acquiring seismic response features of channel sand by performing forward modelling on reservoirs, and determining channel-sand seismic identification marks of different geologic bodies; extracting corresponding seismic attributes according to the channel sand seismic identification marks, and determining a channel boundary; under an isochronous stratigraphic frame, determining sedimentary periods of the channel sand by the aid of the stratal slice technique; determining the thickness of the channel sand according to the statistical fitting relation of the real well-drilling sand thickness and the seismic attributes. According to the method, the channel sand identification and description technology is created by going deep into seismic attribute extraction and analysis, utilizing the reservoir of the fixed well, reservoir calibration results and statistical analysis of well drilling and combining forward model analysis results. Channel sandstone reservoirs of ultra-deep layers, thin sand layers and narrow channels can be identified and described accurately, and influence of seismic resolution is less.

The invention relates to an industrial robot positioning precision calibration method used for improving robot absolute positioning precision. The method comprises the steps that: a robot kinetics model is established; a rotary joint equation is established by using a circumferential method; joint torsion angle parameter values are calculated; the actual pose of a robot end is measured accurately by utilizing a laser tracker; D-H algorithm inversion kinetics equation is improved to obtain geometrical structural parameters; calibration of joint distance parameter values and calibration of joint offset are realized, and thereby first calibration is completed. Error correction is carried out on D-H parameters based on first calibration results, and if positioning precision can not meet requirements, second calibration can be carried out by substituting parameter correction values, instead of theoretical parameter values, into the kinetics equation. Absolute positioning precision of the robot is improved with the calibration method, which is proved in experiments. According to the invention, the calibration method is advantaged in that the method is simple and practical and introduces small external errors.

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 provides a method and system for laser-IMU external parameter calibration. The method comprises steps of acquiring IMU measurement data and laser radar measurement data; carrying out IMUpre-integration of the obtained IMU measurement data, carrying out calculation to obtain an IMU pose transformation estimated value of the IMU relative to the IMU initial pose at the next moment, andaccording to the estimated value and an actual measurement value of the IMU at the next moment, obtaining an associated residual error associated with the data; processing measurement data of the laser radar, utilizing IMU pre-integration to obtain projection coordinates of reprojecting a plurality of laser radar points to a world coordinate system, and calculating a reprojection error from eachlaser radar point to a calibration target map; adopting a nonlinear least square method to iteratively optimize laser radar-IMU external parameter calibration so that the external parameter calibration result can be obtained. The method is advantaged in problems that in laser-IMU external parameter calibration, mechanical external parameters are not easy to obtain, manual measurement errors are large, and measurement is troublesome are solved, defects of the laser radar and the IMU are mutually overcome to a certain extent, and pose solving precision and the speed of the SLAM method can be improved.

The invention discloses a camera and robot relative pose calibration method based on pixel space optimization. According to the method, a calibration board carried at the tail end of a robot is adopted for moving inside the range of the view of a fixed camera, and space motion constraint information of the calibration board is utilized for calibration to obtain the optimal relative pose relation between the camera and a robot base. Firstly, linear invariance of a rotating matrix is utilized for solving a homogeneous transformation matrix to obtain a preliminary calibration result; then, the preliminary calibration result is used as an initial optimization value for optimization of pixel space, so that a reprojection error is made to the minimum. According to the camera and robot relative pose calibration method, the iterative optimization algorithm is adopted, no precision external measurement equipment is needed, model constraints of the image pixel space are utilized, the effective optimization initial value obtaining method is combined, the calibration result with the higher precision is obtained, and the requirement of a visual servo robot for completing positioning and grabbing working in industrial application can be met.