265 results about "Plane equation" patented technology

The invention relates to a vector-relation-based method for calibrating single-line laser radar and a CCD camera. Point set information of the laser radar for scanning a V-shaped target is extracted in a laser coordinate system, and direction vectors and intersection coordinates of straight lines in two different planes of the target are obtained by means of straight line fitting; the CCD camera is used for capturing images in a camera coordinate system, target plane equations and an equation of a plane passing through an original point and laser radar scanning lines are obtained by processing image information, a straight-line equation of laser radar scanning is built, and furthermore, the direction vectors and the intersection coordinates of the straight lines are obtained; finally, calibration is finished according to the relations between direction vectors and the intersection coordinates of the straight lines corresponding to the different coordinate systems. According to the method, no object in a calibration scene needs to be moved, collection of all calibration data can be completed at a time, and calibration efficiency is improved greatly. According to the method, the direction vectors of the straight lines of the laser scanning target planes under the coordinate systems of sensors to be calibrated are obtained directly, calibration precision is guaranteed, and meanwhile the calibration algorithm is simplified.

Two GPS units are mounted at two separate points on the body of a work machine to periodically measure their three-dimensional coordinates with respect to a chosen reference system. As soon as two sets of measurements are recorded, a plane is fitted through the four points so collected and it is used to determined the current orientation of the machine. As each additional set of position data is collected at predetermined intervals for the two points on the machine, a new plane equation is calculated to update the orientation of the machine based on a predetermined number of prior measurements. Standard-deviation analysis is used to check the validity of each plane calculation and the process is restarted when the deviation is found to be greater than an acceptable parameter. Based on the current coordinates of the two GPS antennae, the current orientation plane so calculated, and the known geometry of the work machine, the current position of its critical components can be determined as well irrespective of the specific motion pattern of the machine.

A system and method for extracting structure from stereo that represents the scene as a collection of planar layers. Each layer optimally has an explicit 3D plane equation, a colored image with per-pixel opacity, and a per-pixel depth value relative to the plane. Initial estimates of the layers are recovered using techniques from parametric motion estimation. The combination of a global model (the plane) with a local correction to it (the per-pixel relative depth value) imposes enough local consistency to allow the recovery of shape in both textured and untextured regions.

A global calibration method of a laser tracking visual guidance measurement system comprises the steps of determining a visual system coordinate system and a laser tracker coordinate system; putting a plane target for at least three times and obtaining plane equations of the target plane, where the plane target is located in the visual system coordinate system and the laser tracker coordinate system at each putting position; and calculating a spatial transformation relation of the visual system coordinate system and the laser tracker coordinate system according to the coefficients of the obtained plane equations. The global calibration method of a laser tracking visual guidance measurement system in the invention realizes the global calibration of the laser tracking visual guidance measurement system by obtaining the plane equations of the target plane in the visual system coordinate system and the laser tracker coordinate system at the at least three positions of the plane target, so as to realize automatic assembly and butt joint of large-sized components, to improve assembly efficiency, and to save assembly cost.

The invention discloses a planar component three-dimensional position and normal vector calculation method based on a depth map. the method comprises the steps of: identifying a component through shape matching, and acquiring a dense depth map of an area-of-interest where the component is positioned by using a binocular three-dimensional vision system; carrying out non-uniform sampling and statistical analysis on the dense depth map to remove off-group points; fitting a plane in the dense depth map by using a robust random sample consensus algorithm; and calculating a three-dimensional position and a normal vector of the component according to a plane equation, and providing a conversion method for a camera coordinate system and a world coordinate system. The planar component three-dimensional position and normal vector calculation method has the advantages of high universality, high positioning accuracy and good stability, and is suitable for planar components.

The invention discloses a structured light parameter calibrating apparatus and method based on a front-film-plated plane mirror. The method comprises the following steps: a front-film-plated plane mirror and a plane glass target are placed in front of a camera; the camera simultaneously shoots the image of the plane glass target and a mirror image of the plane glass target; a virtual binocular measurement model is established; optimal solutions of a rotation matrix from a front-film-plated plane mirror coordinate system to a camera coordinate system and a translation vector are obtained by a nonlinear optimization method; image vanishing point solving is carried out on optional feature points by the least squares method; white printing paper is placed in front of the front-film-plated plane mirror, and the camera takes the actual light bar image and the mirror image light bar image; and the center point of the light bar image is extracted to calculate the three-dimensional coordinates of matching points to solve an optical plane equation. According to the invention, the light bar quality is improved and the light bar center extraction precision is raised; feature points with the position precision of the micron order are provided to obtain more calibration points; higher calibration precision is realized; and the calibration result is more stable.

Z-buffer rendering of three-dimensional scenes is made more efficient through a method for occlusion culling by which occluded geometry is removed prior to rasterization. The method uses hierarchical z-buffering to reduce the quantity of image and depth information that needs to be accessed. A separate culling stage in the graphics pipeline culls occluded geometry and passes visible geometry on to a rendering stage. The culling stage maintains its own z-pyramid in which z-values are stored at low precision (e.g., in 8 bits). The efficiency of hierarchical z-buffering is improved through hierarchical evaluation of line and plane equations.

The invention discloses a parcel volume measuring method and system, a storage medium and a mobile terminal, and relates to the field of computer vision. Target point cloud is obtained, and the targetpoint cloud at least comprises the point cloud of a support surface and the point cloud of the top surface of a to-be-measured parcel; a plane equation of the support surface and the plane equation of the top surface of the to-be-measured parcel and the point cloud of the top surface of the to-be-measured parcel are obtained in a plane fitting mode, and the height of the to-be-measured parcel iscalculated according to the plane equation of the support surface and the plane equation of the top surface of the to-be-measured parcel; and the point cloud of the top surface of the to-be-measured parcel is projected on a plane corresponding to the plane equation of the to-be-measured parcel top surface to obtain a boundary point cloud; four frame angle points of the top surface frame of the to-be-measured parcel are obtained; according to the coordinates of the four frame angle points, the length and the width of the to-be-measured parcel are obtained through calculation, and the height ofthe to-be-measured parcel is combined, the volume of the to-be-measured parcel is obtained through calculation. The purpose of reducing the measurement error and simplifying the measurement requirement is achieved.

One embodiment of the present invention sets forth a technique for computing plane equations for primitive shading after non-visible pixels are removed by z culling operations and pixel coverage has been determined. The z plane equations are computed before the plane equations for non-z primitive attributes are computed. The z plane equations are then used to perform screen-space z culling of primitives during and following rasterization. Culling of primitives is also performed based on pixel sample coverage. Consequently, primitives that have visible pixels after z culling operations reach the primitive shading unit. The non-z plane equations are only computed for geometry that is visible after the z culling operations. The primitive shading unit does not need to fetch vertex attributes from memory and does not need to compute non-z plane equations for the culled primitives.

The embodiment of the invention provides a laser radar combined calibration method and device. The laser radar combined calibration method comprises the steps: first point cloud obtained by a first laser radar scanning reference object and second point cloud obtained by a second laser radar scanning reference object are obtained correspondingly; based on the first point cloud, a plane equation ofthe first intersection plane of the reference objects in a first coordinate system of a first laser radar is determined, and according to the plane equation, coordinates of four calibration points inthe first coordinate system are determined, wherein the four calibration points are not coplanar; based on the second point cloud, coordinates of the four calibration points in a second coordinate system of a second laser radar are determined as well; and based on the coordinates of the four calibration points in the first coordinate system and the second coordinate system, a conversion matrix between the first coordinate system and the second coordinate system is calculated to conduct combined calibration on the first laser radar and the second laser radar according to the conversion matrix,and thus the calibration accuracy of laser radar combined calibration is greatly improved.

The invention provides a field calibration method of the structural parameter of a line structure light vision sensing system, comprising the following steps: (a) a movable plane target is put in a measured space, a collinear and three characteristic points with known mutual distance are arranged on the plane target, and the light plane which is projected by a line structure light projector intersects with the straight line at which the three are positioned so as to form a fixed point; (b) the collinear three characteristic points are used for setting up a three-point perspective model, and according to the mutual distances of the three characteristic points, the picpointed coordinates which are imaged on the image surface of a television camera by the three characteristic points and the fixed point, and the internal parameter of the television camera, the coordinate of the fixed point in the coordinate system of the television camera is computed; (c) the plane target is moved to many different positions within measuring range so as to respectively form a plurality of additional fixed points, and the step (b) is repeatedly carried out so as to respectively compute the coordinates of the additional fixed points in the coordinate system of the television camera; and (d) the fixed points which are obtained at many times are fitted into a plane so as to obtain the plane equation of the light plane in the coordinate system of the television camera, thereby completing the field calibration.

The invention discloses a full-automatic calibration method for a structured light hand-eye three-dimensional measuring system. The full-automatic calibration method is designed through deeply analyzing the working principle of a line structured light hand-eye three-dimensional measuring system and is based on three environment feature points and 2 given poses. The calibration method includes that capturing images of three feature points in a scene, and precisely controlling a robot to perform 5 times of translational movement to calibrate intrinsic parameters of a camera and a hand-eye matrix rotating part; giving 2 different poses of the robot, combining with the feature points to form parameter equation information of the plane at different coordinate systems, and calibrating plane equations of a hand-eye matrix translation part and a structured light plane under the coordinate systems of the camera. The calibration method is simple, the feature selection is easy to perform, and the calibration method is important for using the structured light hand-eye three-dimensional measuring system in the actual industrial field.

The embodiment of the invention discloses an indoor scene main structure reconstruction method and system based on a depth image key frame. The method includes: acquiring a depth image: acquiring depth image from a depth camera, processing the depth image to obtain correspond point cloud data, and obtaining a normal vector according to the point cloud data; Calculating a camera pose matrix of thecurrent frame; Judging whether the current frame depth image is a key frame depth image, and if so, adding the current frame depth image into the key frame sequence; Calculating a master structure plane equation set for each frame depth image added to a key frame sequence; Based on the camera posture matrix, the main structure plane equation is transformed from camera coordinate system to world coordinate system. A main structure plane equation set which is added later is register and fused with a main structure plane equation set which is added firstly; Until all the frames in the key frame sequence are processed, the main structure of the indoor scene is reconstructed according to the final fusion set of main structure plane equations.

The invention relates to an obstacle detection method for a blind guiding instrument based on computer stereo vision. According to the invention, an obstacle on the road are detected by using computer stereo vision technologies, the position and contour coordinates of the obstacle are acquired, and a necessary information source is provided for guiding the blind to walk forward. The method is characterized in that road surface images are acquired simultaneously through a binocular camera worn on the body of the blind, feature points in binocular images are extracted by using a feature extraction algorithm, and feature point matching is carried out; then three-dimensional coordinates of a matching point in a left camera coordinate system are calculated, a road surface plane equation is worked out according to the three-dimensional coordinates of the matching point by using a random consistency algorithm; and finally, an obstacle area is distinguished according to the road surface plane equation, and the position and contour coordinates of the obstacle are calculated, thereby providing necessary information for helping the blind to walk forward. According to the invention, road surface obstacle information is provided for travel of the blind, thereby improving travel safety of the blind, and being applicable to the blind guiding instrument so as to guide the blind in travel.

The invention belongs to the technology of acquiring geological structural plane information and particularly relates to a cloud recognition method of a three-dimensional laser scanning point in a geological body structural plane, which is characterized by comprising the following steps of, firstly, determining a geological body structural plane range needing scanning; secondly, determining a plane of the geological body structural plane range needing scanning through three point coordinates which are not on the same line; thirdly, scanning the three point three-dimensional coordinates of the geological body structural plane through a three-dimensional laser, and acquiring a plane equation; fourthly, for rough fluctuation and topography of the determined structural plane, scanning all points on an exposed plane of the structural plane through the three-dimensional laser; fifthly, reselecting a next geological body structural plane, and entering the sixth step if the next plane does not exist; and sixthly, extracting burial parameters of the structural plane from each acquired plane equation, and then carrying out structural plane fitting. The method has important reality and theoretical significances to high and steep side slope geological surveying and rapid geological logging.

The invention relates to a scanning system and a method for three-dimensional images, wherein the system comprises a pick-up device, a rotating device, mutually orthogonal panels and a light source; and the method comprises: 1. transversely arranging the mutually orthogonal panels; 2. calibrating the CCD camera according to a second marking point on the mutually orthogonal panels to obtain the internal and external parameters of the CCD camera; 3. obtaining the plane equation of a linear laser scanning surface according to the internal and external parameters of the CCD camera, the linear laser emitted from the light source and the images of the mutually orthogonal panels; and 4. determining the three-dimensional coordinates of the surface points of the tested objects according to the plane equation of the linear laser scanning surface and the equation of straight line of the linear laser images. The invention reduces the cost, overcomes the limits to the surface matching of the scanning curve sheets based on a triangle relation in the prior art, and improves the efficiency, precision and flexibility of the scanning by arranging a rotating table and transversely arranging mutually orthogonal panels.

The invention discloses a method for automatically extracting building information in airborne laser radar point clouds. According to the invention, an airborne laser radar system is employed to carry out data acquisition on a target zone, three point clouds which are not coplanar are randomly selected from original point clouds according to a constraint condition, the equation of a plane determined by the selected point clouds is calculated in dependence on space coordinates of the selected point clouds, the distance di between each point cloud and the plane is calculated, the standard deviation [sigma] of the distance is calculated, and the threshold t is set to satisfy the formula t=2 [sigma]. When di is larger than t, the point cloud is classified as an outside point, conversely, the point cloud is classified as an inside point, and the number of the inside points is counted up; the above steps are iterated for certain times, a plane including the most inside points is selected, the point clouds in the obtained plane model are removed, residual points serve as an original point cloud data set for next processing, the above steps are repeated until all point cloud planes of the building are extracted, and finally a part of misclassified point clouds are removed by means of three-dimensional morphological corrosion operation. According to the invention, the building point cloud extraction speed and precision are improved.

The invention discloses a universal method for forecasting in-target situation of guide drilling. The universal method includes: on the basis of survey data of last two survey points of a real drilling trajectory, calculating trajectory characteristic parameters of unsurveyed sections; calculating trajectory parameters of a well bottom point on the basis of the trajectory characteristic parameters of the unsurveyed sections of the real drilling trajectory; establishing coordinate transformation relations between a general target plane equation as well as a target coordinate system and a wellhead coordinate system; according to a landing-controlled anticipating guide drilling technology, determining a borehole trajectory model and the trajectory characteristic parameters of a forecasting trajectory and establishing a coordinate equation of the forecasting trajectory; establishing and calculating a constraint equation of the forecasting trajectory to acquire well section length of the forecasting trajectory; calculating the in-target location and judging whether a target is in place or not and forecasting the in-target direction. By the universal method, the target-in location and the target-in direction can be forecast, and the universal method is applicable to different well types like directional wells and horizontal wells even to special formed target sections and various drilling modes like sliding guide drilling, rotating guide drilling and composite guide drilling.

The invention discloses a line structure light vision sensor calibration method based on a parallel bicylindrical target. The method comprises the following steps: placing a target at a proper position at least once by use of the parallel bicylindrical target which moves freely, and a line structure light vision sensor shooting a laser light stripe image on the target; extracting the center point of the light stripe image, and fitting an elliptical image of a light stripe in the image; based on perspective projection transformation, establishing a corresponding equation between two space ellipses and their images; solving a light plane equation by taking equivalence between the short axes of the ellipses and the diameter of a cylinder as a constraint condition; and obtaining an optimal solution of the light plane equation through a nonlinear optimization method. The method provided by the invention is suitable for calibration of a line structure vision sensor in an onsite complex light environment and even under the condition that a camera is provided with an optical filter, and is especially suitable for onsite rapid high-precision calibration of multiple line structure light vision sensors in a narrow space or at difference angles.

The invention discloses a document image distortion rectifying method based on structured laser beams. The method at least comprises the following steps: calibrating the intrinsic and extrinsic parameters of a camera and calculating a plane equation of structured laser beams; obtaining a document image; extracting laser beams; estimating a 3D page neatline of the document image according to the calibrated intrinsic and extrinsic parameters of the camera, the plane equation of structured laser beams and the extracted laser beams; performing interpolation on the developable surface according to the 3D page neatline; developing the developable surface with interpolation; and rectifying the image distortion according to the developed developable surface. According to the invention, technical problems of rectification of geometrical distortion of a non-planar document image can be resolved.

The embodiments of the invention provide a speckle structured light-based high-precision depth calculation method and system. The method includes the following steps that: the image information of acalibration plate on a reference plane is acquired, the coordinates of feature points of the image information in a camera coordinate system are calculated through a camera calibration algorithm; theplane equation of the reference plane in the camera coordinate system is calculated according to the coordinates of the feature points in the camera coordinate system; the speckle pattern of the reference plane is acquired, the parallax of speckles in the pattern is calculated according to the speckle pattern; and the depth of a target position point on the reference plane is calculated accordingto the plane equation in the camera coordinate system and the parallax of the speckles. According to the method provided by the embodiments of the invention, the precise pose of the reference plane iscalculated through the plane equation and the parallax of the speckles, and therefore, error transmission is fundamentally reduced, and depth calculation accuracy is greatly improved.

The invention belongs to the field of calibration of connecting rod parameters of an industrial robot, in particular to a calibration method of the connecting rod parameters of the industrial robot based on end-point plane constraint. The calibration method comprises the following steps: (1) establishing a connecting rod coordinate system and a tool coordinate system of the industrial robot, and thus obtaining the end position coordinate of the industrial robot; (2) conducting plane constraint for an end point, and establishing an error identification model of the connecting rod parameters ofthe industrial robot; (3) transforming the postures of the industrial robot, recording the joint values of joint variables and the length of a laser beam, and calculating the initial parameter of a plane equation according to the position coordinates of the first three poses; (4) conducting error identification for the connecting rod parameters of the industrial robot; and (5) correcting parameters to be corrected in order, and verifying the precision of the corrected industrial robot. The calibration method can conduct calibration in the larger working space of the industrial robot, can realize fully automatic calibration, and has high calibration precision and low cost.