97 results about "Ellipse" patented technology

The invention provides a gear peeling time-varying meshing stiffness prediction method and system based on a back propagation neural network, and the method comprises the steps: considering a tooth surface peeling fault based on a gear tooth bearing contact analysis method, and constructing a helical gear pair time-varying meshing stiffness calculation model; a real irregular tooth surface peeling area is fitted by adopting a least square ellipse fitting method to obtain an ellipse appearance representation, any peeling position is completely described through six key geometric parameters, the geometric parameters of the ellipse appearance are systematically traversed and fitted, and diversified peeling appearance samples are generated. Introducing a tooth profile deviation matrix corresponding to the peeling morphology sample into a tooth surface bearing contact analysis model, and constructing a training data set; and constructing a back propagation neural network model of multiple hidden layers, and performing end-to-end training by using the training data set, so that the back propagation neural network model learns a nonlinear mapping relationship from geometric parameters to a time-varying meshing stiffness curve, thereby predicting the time-varying meshing stiffness under any peeling morphology.

The invention discloses an ultrasonic guided wave damage ellipse imaging positioning method and equipment for a layer decreasing composite material laminated plate. The method comprises the following steps: S1, acquiring thickness change direction information of the laminated plate and position coordinates of an excitation transducer and a receiving transducer; s2, according to the material characteristic parameters, simulating and calculating the propagation time of ultrasonic guided waves transmitted from an excitation transducer to any point to generate a first theoretical propagation time map, and simulating and calculating the propagation time of the ultrasonic guided waves transmitted from any point to a receiving transducer to generate a second theoretical propagation time map to generate a second theoretical propagation time map; coupling influence of thickness change and material anisotropy on guided wave propagation is considered in the simulation process; s3, transmitting an ultrasonic guided wave signal, and extracting the actual flight time of a damaged wave packet; s4, calculating theoretical total propagation time, and determining a candidate area where damage exists; and S5, on the basis of repeated operation of the multiple groups of transducer pairs, taking a plurality of candidate region intersections to determine a final damage position. The objective of the invention is to solve the positioning error problem caused by the structural characteristics of a laminated plate in a traditional algorithm, and to realize more accurate damage detection and positioning.

The invention discloses a shield segment splicing elliptic change detection method, relates to the technical field of shield segments, and breaks through the limitation that in traditional detection, elliptic change and slab staggering are detected separately, and judgment depends on artificial experience. An integrated design of circular seam point cloud accurate screening-double circular seam plane fitting correction-least square circle fitting and ellipsometry parameter linkage calculation is adopted, secondary correction is performed through a second circular seam plane equation, the problem that single circular seam plane fitting is easily influenced by model reconstruction errors is solved, the fitting precision is improved, and the fitting precision is improved. The technical closed loop of section geometric feature extraction-ellipse parameter quantization-slab staggering reference calibration is achieved, meanwhile, least square circle fitting of YZ section point clouds is combined with ellipse long axis, ellipse short axis, ellipse rate and deformation deviation calculation depth, ellipse judgment is achieved through double threshold values of ellipse rate grading and deformation deviation threshold values, the risk of misjudgment of a single parameter is avoided, and the method has the advantages of being high in practicability and high in practicability. And a high-precision reference surface is provided for subsequent slab staggering quantity calculation.

A phase difference sheet including a substrate and a phase difference film as a tilt film, wherein, in a biaxial refractive index ellipsoid exhibiting a refractive index anisotropy, of three principal refractive indexes nx, ny, nz, the principal refractive index in the length direction of a columnar structure, i.e., the X-axis direction, is nx, the principal refractive index in the major axis direction of an ellipse perpendicular to the X-axis, i.e., the Y-axis direction, is ny, and the principal refractive index in the minor axis direction, i.e., the Z-axis direction, is nz, the following conditional expression (1) is satisfied, and, in a case where the incident angle of a direction tilted to the X-axis side with the normal as a reference is positive, the phase difference of incident light at an incident angle of +30° is Re(+30), the phase difference of incident light at an incident angle of -30° is Re(-30), and the ratio of Re(+30) to Re(-30), i.e., the phase difference ratio, is Re(30) ratio, the following conditional expression (2) is satisfied, ny > nx > nz (1), Re(30) ratio = Re(30) / Re(-30) = 1.1 to 4.0 (2).

The invention provides a high-temperature and drought composite disaster monitoring and early warning method and system, and relates to the technical field of disaster monitoring and early warning, and the method comprises the steps: 2, extracting a data subset from a fusion data set, constructing a feature analysis region according to a preset reference relation, selecting a core analysis unit in the feature analysis region as a focus of an ellipse, and carrying out the calculation of the data subset; selecting an external reference unit as another focus of the ellipse in an adjacent spatial range, and calculating the spatial form and dynamic change of an eccentricity quantization region of the ellipse; according to the incidence relation of the core analysis unit and the external reference unit along with the time change, an analysis path is generated, an environment parameter correction coefficient is calculated to calibrate related elements in the fusion data set, and a calibrated fusion data set is obtained. According to the invention, probability prediction and dynamic early warning of high-temperature drought composite disasters are realized, and the reliability and real-time performance of disaster early warning are improved.

The application discloses a kind of based on multi-focal sharpness analysis's stacked cell hierarchy determination method and system.Acquire Z-stack multi-focal image sequence and extract each focal plane cell contour;Based on centroid coordinates and area features, establish the profile correlation data table of the same cell in different focal planes;Ellipse fitting algorithm is used to complete the shape of the profile of the cell that is blocked;Based on complete geometry mask, screen potential stacked candidate cell pair and locate overlapping area profile;With gradient function as evaluation index, calculate the overlapping area profile sharpness of each cell under multiple focal planes, determine the best focus focal length and judge cell hierarchy relationship;Attribute graph is constructed and topological sorting is executed, and global stacked hierarchy sequence is output.The application establishes hierarchy reasoning rule with rigorous physical basis according to the physical law that upper cell best focus focal length is higher, is compatible with existing Z-stack imaging process, adapts to basic laboratory high-throughput analysis demand.

The application discloses a kind of workpiece inner hole profile ellipse detection method, computing device and storage medium, method includes: based on predetermined angle step, obtain inner hole profile point set from the inner hole image of workpiece;Randomly obtain a predetermined number of profile points from inner hole profile point set;Whether the distance between any two profile points is greater than the first distance threshold value is judged;If yes, then based on the predetermined number of profile points fitting forms initial ellipse;Next profile point is randomly obtained from inner hole profile point set, whether the distance of next profile point to initial ellipse is less than the second distance threshold value is judged;If yes, then determine the target coverage angle value of all target profile points in inner hole profile point set to initial ellipse distance less than the second distance threshold value;Whether target coverage angle value is greater than the first coverage angle threshold value is judged, if yes, then according to initial ellipse obtains ellipse parameter.According to the technical scheme of the application, it is favorable to improve ellipse detection efficiency and precision.

The present application relates to geodetic and engineering surveying technical field, specifically to a kind of plane coordinate point cloud fitting arbitrary close degree error ellipse in control network design stage.The method includes: the pre-processing of control point coordinate point cloud, removes abnormal value;Accurate spatial precision evaluation density field is constructed to calculate grid point density value;According to the specified confidence, the density threshold value is calculated, the contour is extracted and the error ellipse parameter is fitted.The present application solves the ellipse fitting problem of any specified confidence of non-normal distribution point cloud by adaptive bandwidth kernel density estimation, and significantly improves the reliability of precision evaluation under complex scene.

The present application belongs to the field of cable eccentricity detection, and particularly relates to a cable eccentricity detection method and system based on X-ray. The method calculates gradient amplitude graph and gradient direction graph through X-ray image of the cable, screens points with local maximum gradient amplitude and low neighborhood divergence as contour starting points, generates contour point set through contour tracking, and selects next contour point based on tangent prediction direction. Then, the contour point set is subjected to ellipse fitting, the geometric center, long and short axis parameters and root mean square error of the fitted ellipse are obtained, the fitted ellipse is divided into inner and outer candidate ellipses according to the long axis, and each outer candidate ellipse is paired with the inner candidate ellipse meeting the condition. The outer candidate ellipse and the inner candidate ellipse meeting the condition are screened from the candidate pair, and the eccentricity of the cable to be measured is calculated based on the geometric center coordinates of the two. The present application can improve the accuracy and reliability of the cable eccentricity measurement result.

The application discloses a kind of positioning method and related equipment based on image, method includes: shooting environment, obtain the mark image for the positioning image of pre-set, wherein the positioning image includes DM code from inside to outside, circular mark and several mark blocks;Based on the circular mark, the mark image is carried out ellipse detection, and ellipse position information is obtained;According to the ellipse position information, the mark three-dimensional coordinates corresponding to the DM code are extracted;And, according to the ellipse position information, the block coordinate information corresponding to the mark block in the mark image is determined;According to the block coordinate information, the mark two-dimensional coordinates corresponding to the positioning image are calculated;According to the mark two-dimensional coordinates and the mark three-dimensional coordinates, the positioning information corresponding to the mark image is calculated.The application can significantly improve the speed and accuracy of positioning.

The invention discloses a method for calculating an approximate circle diameter in a touch algorithm, which comprises the following steps of: 1, calculating a central physical coordinate according to original data obtained by touch, and taking the central physical coordinate as an expected value; step 2, calculating a covariance; step 3, constructing a covariance matrix; 4, performing eigenvalue decomposition on the constructed covariance matrix to obtain eigenvalues; step 5, calculating an initial ellipse semi-axis length through the characteristic value; step 6, calculating an equivalent diameter; step 7, simulating a curve equation by using a plurality of samples; and step 8, when actual touch occurs, obtaining the equivalent diameter through the steps 1-6, and calculating to obtain the diameter of the touch object. According to the method, eigenvalue calculation processing is carried out on the original covariance matrix, the contour of a real touch area can be accurately fitted, coordinate distribution characteristics in a theoretical model are considered, original data and physical size factors of a sensor are combined, and therefore the accuracy of touch size calculation is remarkably improved.

The application provides a distributed rotary scanning probe structure parameter calibration method, and relates to the field of precise optical measurement instrument calibration, and specifically comprises the following steps: establishing a measurement model of a rotary scanning probe; placing a temperature sensor at a heat generating part in a distance measuring system, recording the change relationship between the distance measuring value and the temperature in the stationary working state of the rotary scanning probe, and calibrating the temperature coefficient; performing temperature compensation on the original distance measuring value to obtain a compensated distance measuring value; according to the internal structure of the rotary scanning probe, an initial calibration value is given, point cloud data is subjected to least square ellipse fitting processing, and a fitted radius value is obtained; the fitted radius value of each group of point cloud data is compared with the true circle radius, a PSO-LM hybrid algorithm is used for iteration, and the optimal calibrated structure parameter is obtained. The technical scheme of the application overcomes the problems of the prior art, such as complicated operation, poor fault tolerance and unsuitability for rapid calibration requirements in the production site.

The invention discloses a station weighting-based micro-seismic event plane positioning confidence ellipse calculation method, which comprises the following steps of: screening P-wave arrival time data simultaneously received by a plurality of stations, and calculating an initial seismic source position coordinate and an arrival time residual error of each station; the arrival time equation is linearized, and a design matrix and an initial weight matrix are constructed; constructing a normal equation based on the design matrix and the station weight matrix, solving a parameter correction amount, and updating a seismic source position coordinate and a seismic moment; calculating a covariance matrix and extracting a sub-matrix, performing eigenvalue decomposition to obtain eigenvalues and eigenvectors, and calculating an ellipse area under a preset confidence level; respectively resetting the weight of each station to zero, recalculating the area of the confidence ellipse, constructing an influence index of the station on the area of the ellipse, and adjusting the weight of the station according to the influence to obtain an updated weight matrix; and judging a convergence state based on the relative change rate of the confidence ellipse area, and outputting a final seismic source plane position and confidence ellipse parameters during convergence. According to the invention, rapid and accurate positioning operation of a micro-seismic monitoring scene can be realized.

An authentication system using an elliptic equation, according to an embodiment of the present application, comprises: a first apparatus that generates ellipse information regarding a predefined elliptic equation; and a second apparatus that is provided to communicate with the first apparatus, receives at least a portion of the ellipse information, transmits, to the first apparatus, credential information generated on the basis of geometric properties of an ellipse defined in the received ellipse information, and is authenticated by the first apparatus, wherein the first apparatus may authenticate the second apparatus by using the credential information received from the second apparatus.

This invention belongs to the field of pipeline inspection technology, specifically relating to a pipeline inner diameter measurement system and method based on stepping rotation scanning. A drive module drives a ranging sensor to rotate stepwise around a motor axis within a circular cross-section pipeline. A control module collects the radial distance from the sensor to the pipe wall at preset angular intervals, obtaining N sets of angle-distance data covering the entire circumference of the pipeline's inner wall, and converts these into a set of Cartesian coordinate points. After randomly sampling and iteratively removing abnormal coordinate points, ellipse fitting is performed to extract the length of the minor semi-axis of the ellipse. When the fitting result is an ellipse, twice the minor semi-axis is taken as the pipeline inner diameter; when the fitting result meets the circularity criteria, the diameter of the fitted circle is taken as the pipeline inner diameter. This invention is based on the geometric principle that the minor semi-axis of an ellipse with an oblique cylindrical cross-section is always equal to the radius of the cylinder. It eliminates the need to place the device at the center of the pipeline or calibrate the parallelism of the sensor axis; accurate measurement can be achieved regardless of the device's placement.

The application discloses a kind of chromaticity instrument measurement display product chromaticity coordinate area determination method, including (1) chromaticity coordinate stability determination;(2) chromaticity target area optimization;(3) chromaticity target area attribution determination optimization;Traditional stability determination mode is single dimension, CIE1931 original chromaticity coordinate is provided in the form of discrete data with 1nm as wavelength interval, sampling interval is larger, precision is limited, traditional attribution determination is large in amount of calculation for chromaticity diagram of data point dense, according to covariance matrix construction minimum chromaticity ellipse, the spatial distribution characteristics of point set is determined by analysis chromaticity coordinate stability;Original chromaticity point is fitted using piecewise polynomial interpolation, and the coordinate precision is optimized to 0.01nm, two-stage rapid determination strategy is used, first based on polar angle realizes candidate sector preliminary screening, then in the local candidate sector obtained by preliminary screening, accurate determination is carried out using local ray method, and target area positioning of chromaticity coordinate is completed.

This invention provides an optical guidance method for the recovery of deep-sea unmanned underwater vehicles (UUVs), belonging to the field of underwater vehicle recovery technology. The invention involves installing four blue-green LED guidance light sources in a non-uniform ring distribution on the front face of the recovery cage and pre-calibrating their three-dimensional coordinates. A binocular camera is used to acquire images of the guidance light sources in real time. Adaptive exposure control technology is employed to adjust image quality. Statistical information calculations are performed on the identified light source contours, and effective guidance light source targets are determined through convex constraint configuration judgment and ellipse fitting. The four guidance light sources are constructed as a traveling salesman problem, and a nearest neighbor heuristic algorithm is used to complete numbering matching. Based on pre-measured coordinates and real-time calculated coordinates, the rotation matrix and translation vector are solved using singular value decomposition, while simultaneously performing collaborative optimization. This method solves the technical problems of insufficient optical guidance positioning accuracy and poor real-time performance during the recovery of UUVs in deep-sea environments.

The invention relates to a support multi-degree-of-freedom pose monitoring method and device based on machine vision, and the method comprises the steps: collecting a pier top integrated target image, carrying out the graying processing and contour extraction, and carrying out the ellipse fitting of a contour, so as to obtain geometric parameters; screening according to an ellipse inclusion relation to form an identification code unit, establishing a local rounding coordinate system, and degenerating an ellipse into a perfect circle through coordinate transformation; constructing a vector under the rounded coordinate system, calculating a signed included angle, and carrying out normalization processing; performing interval matching based on the normalized angle to decode the unique identifier, and synchronously outputting a high-precision circle center coordinate; and finally, combining at least four identification code circle center coordinates, solving a camera pose by adopting a 3D to 2D point pair projection method (PnP), aligning to a support coordinate system through calibration transformation, and outputting a six-degree-of-freedom pose parameter. Compared with the prior art, the non-contact high-precision pose monitoring is realized, and the method has submillimeter-level measurement precision and strong environmental adaptability.

The application provides a detection method and system for a winding centering deviation, comprising the following steps: S1, constructing and training a centering deviation detection model; arranging an illuminating device and a camera device to capture images at intervals; S2, inputting the images into the centering deviation detection model, calculating the center coordinates of an ellipse in the images, and then calculating a pixel deviation value; obtaining an actual deviation distance according to the pixel deviation value; S3, drawing a trajectory of the ellipse on the images; S4, judging whether the actual deviation distance is greater than or equal to a threshold value; if the result is yes, storing current data and issuing a warning signal; and if the result is no, storing the current data. The application can detect the centering height of a steel coil with high precision through visual recognition, avoid the occurrence of the winding phenomenon, and reduce the labor intensity of an operator.

The invention discloses an image-based space target physical parameter identification method. The method comprises the following steps: acquiring multiple frames of continuous images in a process of capturing a space target by a service satellite by using a camera; the method comprises the following steps: converting an image into a grey-scale map, identifying an identification point preset on a service satellite in the image, performing ellipse fitting on a closed contour of the image to obtain coordinates of the identification point to pre-generate a multi-angle rendering image set, establishing a mapping relation library of 2D pixel coordinates of the identification point and known 3D coordinates, and resolving pose information of the service satellite; estimating a camera pose and a space target pose; and calculating to obtain the position of the mass center of a combination body formed after the service satellite captures the space target. According to the embodiment of the invention, the method achieves the high-precision calculation of the position of the center of mass of the combined body, obtains the initial value of a physical parameter which can be directly applied to the subsequent dynamic identification, avoids the dependence of contact excitation on fuel and structure safety, enables the identification process to be higher in safety and task sustainability, and improves the recognition efficiency. And the efficiency and the reliability of parameter identification are obviously improved.

The application discloses a multi-round-hole visual size detection method based on feature clustering and Kalman correction, collects the image of the end face of the multi-round-hole target workpiece on a conveying belt, and carries out gray processing; performs ellipse detection based on a deep learning method, and divides out an interest region containing an ellipse feature in the image; extracts the contour of each interest region and carries out screening; adopts a DSRSAC method to perform ellipse parameter fitting, solves the geometric characteristic parameters of the ellipse, and quantifies the uncertainty of each geometric characteristic parameter; through uncertainty weighted clustering and feature screening, a geometric characteristic parameter set with the maximum similarity is obtained, an ellipse fitting result is output, the round-hole diameter is calculated, and optimization is carried out based on the same; all round-hole diameter detection results of the multi-round-hole end face of the target workpiece are output, and the size detection of the round hole is completed. The application is suitable for an industrial assembly line scene, continuously corrects the detected round-hole diameter, and improves the accuracy and reliability of the detection result.

The application discloses an ellipse fitting method and device for a visual detection system and a visual detection system, and belongs to the technical field of data processing. The method comprises the following steps: fitting an ellipse for a workpiece data point set to be fitted to obtain a first fitting ellipse, wherein the workpiece data point set is obtained by collecting a target workpiece by a data collection device of the visual detection system; determining inliers and outliers in the workpiece data point set based on distances from each workpiece data point in the data point set to the first fitting ellipse and an inlier distance threshold; fitting an ellipse for the inliers in the workpiece data point set to obtain a second fitting ellipse; iteratively updating the inliers and the outliers in the workpiece data point set based on the second fitting ellipse; and fitting an ellipse for the updated inliers in the workpiece data point set to obtain a target fitting ellipse on the target workpiece. The method can obtain a fitting ellipse with stable results and high fitting precision.

The application provides a secant approximation method for nonlinear constraints of a redundant drive system, and belongs to the technical field of dynamic control distribution of the redundant drive system. The method comprises the following steps: firstly, according to the control input model of the redundant drive system with any pair of constraint components being nonlinear constraints, a closed region formed by the intersection of a rectangle and an ellipse in a geometric plane is obtained; then, after the closed region is divided into the union of the rectangle and the ellipse triangle, the approximation result of the closed region is obtained by performing the approximation of the rectangle and the triangle combination on the ellipse triangle, so that the linear approximation of the pair of nonlinear constraint components is realized. The application jointly uses the triangle and the rectangle to perform the approximation on the region surrounded by the nonlinear constraints, converts the nonlinear constraints into multiple linear constraints, converts the nonlinear constraint set into a linear constraint set, effectively solves the problem that the control reachable set cannot be determined due to the nonlinear constraint relationship between the actuators in the redundant drive system, and is helpful to realize the real-time control of the redundant drive system.

A characterization system (1) for characterizing a material or substance of an object or moving body, comprising a measuring chamber (12) having a reflective wall (3) capable of reflecting radar waves and a support wall on which a radar wave transmitter / receiver device (5) is mounted, wherein the reflective wall has a general concave channel shape and a principal cross-section that passes through the radar wave transmitter / receiver device and is inscribed in an ellipse having a first focus (81) and a second focus (82), and an axis of the ellipse (80) passing through the first and second focuses; and the first focus is positioned on the radar wave transmitter / receiver device and the second focus is positioned inside the reflective wall. Abstract figure: Figure 8

1. Name of the design product: ring (North Pole ellipse seven stars). 2. Use of the design product: the design product is used for wearing on the hand. 3. Design points of the design product: in shape. 4. Picture or photo best indicating the design points: perspective view.

The application provides a method for expanding a foreground region, which draws a foreground contour map on the basis of a foreground binary map, frames a minimum rectangular frame of the contour map, compares w points farthest and nearest to the rectangular frame in a width w direction, draws an ellipse with the intersection point coordinates of the farthest and nearest points as the center points of the ellipse, sets all pixel points from the inside of the ellipse to the foreground contour part as foreground points, and thus obtains an expanded foreground binary map. Since the farthest and nearest points do not necessarily contain the whole height h direction of the rectangular frame, many pairs of the farthest and nearest points are obtained, and each pair of the farthest and nearest points draws an ellipse. On the basis of frame difference, the foreground region is expanded, so that the foreground region which cannot be displayed due to the same foreground and background colors is normally displayed.

The invention discloses a method for calculating oil casing deformation based on logging inner diameter big data, and belongs to the technical field of oil well pipe measurement, and the method is specifically implemented according to the following steps that a multi-arm caliper moves in an oil casing in the axial direction, and inner diameter information of the section of the oil casing under the eccentric condition is obtained; coordinate processing is carried out on the inner diameter information, and the ellipse area S and the ellipse perimeter H in the cross section of the oil casing are calculated; and calculating the long semi-axis length a and the short semi-axis length b of the deformed ellipse of the inner surface of the cross section of the oil casing according to the ellipse area S and the ellipse perimeter H. According to the inner diameter information measured by logging, the ellipse area and the ellipse perimeter are obtained, the long semi-axis length and the short semi-axis length of the ellipse of the deformed oil casing are further obtained, the ellipse shape of the deformed oil casing is accurately quantified, the accuracy and the reliability of strength calculation and safety check of the deformed oil casing are improved, and the working efficiency is improved. The technical problem that in the prior art, the geometrical shape of the deformed oil casing cannot be truly reflected, and consequently the deviation between the strength calculation result of the deformed oil casing and the actual value is large is solved.

This application provides a method, apparatus, device, and medium for acquiring the tip shape phenotype of a blade. The invention acquires the original image of the target blade using image processing technology; preprocesses the original image to obtain a preprocessed image; performs edge detection on the preprocessed image to obtain an edge-detected image of the target blade; performs contour extraction processing based on the edge-detected image to obtain a contour image of the target blade; performs ellipse fitting on the contour in the contour image to obtain a fitted ellipse of the target blade contour; and determines the tip shape phenotype of the target blade based on the eccentricity of the fitted ellipse and a preset mapping relationship between the eccentricity and the tip shape phenotype. This invention uses eccentricity, a digital phenotypic index, to quantify the tip shape phenotype, which was originally only qualitatively describable, thus improving the efficiency and accuracy of blade phenotypic information acquisition and analysis in DUS testing.

The invention discloses a large-viewing-angle visual positioning method based on geometric constraints of dynamic and static objects, and relates to the technical field of computer vision. The method aims at solving the problem that the pose estimation precision is reduced due to feature matching failure under the large view angle change in the existing feature point-based positioning technology. The method comprises the following steps: identifying an object from an image pair synchronously acquired by a multi-camera system, fitting the contour into an ellipse, and distinguishing a static ellipse from a dynamic ellipse; reconstructing an object motion vector by using the projection change of the dynamic ellipse, establishing a rotation constraint based on the invariance of the object motion vector, and solving the initial estimation of the relative pose between the cameras in combination with a non-rolling constraint; constructing an epipolar geometric space by using the initial estimation, and establishing a corresponding relation by defining an ellipse distance function and matching a static ellipse; and finally, combining geometric constraints of dynamic and static ellipses to construct an optimization model, and performing nonlinear optimization on the relative pose parameters of the camera to obtain a high-precision estimation result. According to the method, robust geometric constraints provided by dynamic and static objects in a scene are utilized, so that the robustness and precision of visual positioning under large visual angle difference are remarkably improved.

A kind of method for determining the actual ball size of a ball cage type universal coupling belongs to the technical field of ball cage type universal coupling design.The method is as follows: coupling parameter analysis;calculating the difference between the theoretical ball and the center of the ellipse and the difference between the actual ball and the center of the ellipse;calculating the actual ball center size.The present application combines mechanical expertise,analyzes the tangent of the elliptical orbit and the ball,according to the different situations of the inner planet wheel and the outer planet wheel,calculates the actual ball center size directly,avoids the repeated modeling work of three-dimensional model analysis in the prior art,significantly improves the measurement efficiency,enhances the universality of the method and expands the scope of application.