11 results about "Plane equation" patented technology

The application discloses a lightweight indoor 3D laser ground extraction algorithm method, system and medium. The method comprises the following steps: acquiring indoor 3D laser radar data; obtaining coordinate values based on a laser radar coordinate system according to the indoor 3D laser radar data; sending the coordinate values to a preset plane equation to obtain a ground plane normal vector; sending the ground plane normal vector to a first preset coordinate system to establish a constraint to obtain a comprehensive error value; and accumulating squares of values in the comprehensive error value to obtain a comprehensive error sum of squares; extracting a minimum value in the comprehensive error sum of squares, and setting a coordinate point corresponding to the minimum value as an optimal current pose. The application is suitable for various lasers, and by giving a preset threshold, whether it is 16 lines, 32 lines or 128 lines, the algorithm accuracy and robustness are ensured, and the accuracy of recognized ground points is improved.

The application discloses a method for analyzing bearing capacity of two-span concrete floor slabs under column end constraints, comprising: obtaining position parameters of the concrete floor slabs, calculating displacement coefficients of different beams based on the position parameters; establishing slab plane equations of a yield line load stage based on the displacement coefficients, obtaining slab rotation angles of each slab along x and y coordinate axes based on the slab plane equations; calculating yield line load values according to the virtual work principle based on the slab rotation angles; calculating membrane force parameters based on force balance equations, moment balance equations and elliptical regions of each slab; establishing plane equations of each slab under a limit state, calculating bearing capacity increase coefficients according to the plane equations; obtaining a total increase coefficient based on the force equivalence principle, and obtaining a limit bearing capacity based on the total increase coefficient and the yield line load values. The application can make the bearing capacity of the reinforced concrete floor slabs under column end constraints have a smaller error compared with the actual situation.

This invention discloses a GPU-based method and system for culling invisible objects. The method calculates the six plane equations of the view frustum of the observation camera and the world coordinates of each observed object. It then uses the GPU to calculate in parallel the front or back face of each observed object on a certain plane of the view frustum, thereby determining whether the object is outside the view frustum and culling all objects outside the view frustum. Next, hierarchical Z-buffer data is generated in the GPU using the depth map of the current frame. The object's position and other information are passed to the GPU and used to calculate with the hierarchical Z-buffer data, culling completely occluded objects. This invention utilizes the parallel computing power of the GPU, improving culling efficiency, significantly reducing the CPU computational burden during rendering, and reducing the probability of culling errors.

The application provides a plane constraint-based spectral confocal probe pose calibration method and device, and belongs to the field of precision measurement and instrument technology.The method comprises the following steps: firstly, at least three non-coplanar plane standard parts are measured by using a contact probe, and through coordinate conversion and fitting, equations of the standard planes in a machine coordinate system are accurately established; then, the same plane parts are measured by using a spectral confocal probe, and the obtained measurement point coordinates and distance values are combined with the known plane equations to construct a linear over-determined equation set about the probe pose parameters (including an optical axis direction vector and a space position vector); finally, the equation set is solved by using a least square method to obtain accurate pose parameters.The application converts a nonlinear problem into a linear solution, avoids iterative calculation, and significantly improves the calibration efficiency and accuracy.Meanwhile, the use of plane constraint allows the measurement points to be uniformly distributed, effectively reduces the equation set ill-conditioning, and enhances the robustness of the calibration process.

The application discloses a repetitive building element retrieval method based on axial movement and local matching, and specifically comprises the following steps: carrying out preliminary segmentation and optimization on a building facade scene; randomly selecting a building element sample under user driving; determining the X axis of the building facade and other two axes by solving a plane equation; transforming the building element sample to the left lower corner origin of the building facade scene by using an OBB bounding box; extracting key points of the element to be retrieved by using an internal shape descriptor; constructing a local matching constraint by combining FPFH and the OBB bounding box; finally, finding the nearest point of the key points of each element to be retrieved, comparing the difference between the descriptors by using the Euclidean distance, and completing the retrieval of the repetitive building element. The application can directly retrieve the repetitive building element in the building facade scene, and solves the problems of the fuzziness of the retrieval object and the low recall rate in the previous retrieval methods.

This invention discloses a high-precision 3D edge reconstruction method for bevel cutting. The method first acquires the original point cloud and grayscale image of the workpiece using a binocular vision system; then, it uses the filtered clean point cloud to fit the plane equation of the workpiece surface as a geometric constraint; next, it performs adaptive feature enhancement on the grayscale image to extract high-precision sub-pixel 2D edges; finally, it combines the plane equation and the 2D edges, calculates the 3D coordinates of the edges using a ray intersection model, and generates the robot cutting trajectory. This invention effectively solves the problems of point cloud loss and distortion caused by edge burrs, defects, and reflections, achieving sub-millimeter-level edge reconstruction and significantly improving the consistency of bevel cutting edges and trajectory accuracy without manual intervention.

The application discloses a method for measuring close-packed hexagonal lattice constant based on space plane fitting, which comprises the following steps: firstly, obtaining the X-ray diffraction spectrum of a close-packed hexagonal crystal and indexing; secondly, converting the crystal plane spacing formula into a three-dimensional space plane equation through mathematical transformation; thirdly, calculating a plurality of groups of data according to the measured diffraction angle and performing space plane fitting to obtain a space plane equation containing an intercept; fourthly, introducing a goniometer zero drift error correction quantity to perform multiple iteration correction on the measured angle until the absolute value of the intercept of the fitting plane tends to be zero, so that the accurate value is obtained; and finally, calculating the high-precision lattice constant. The application converts the complex parameter fitting problem into an intuitive space plane fitting and intercept correction process, has clear principle and strong operability, and effectively improves the measurement precision of the close-packed hexagonal lattice constant.

The invention discloses a plane rectangular heliostat field shadow efficiency algorithm, which improves a common heliostat shadow efficiency calculation method based on a geometrical relationship, and has the advantages of simplicity in calculation, high accuracy and convenience in understanding. The calculation thought is as follows: screening neighbor heliostats: only considering potential shielding mirrors within a distance threshold (reducing the calculation amount); constructing a key vector: calculating a sun incidence vector and a heliostat normal vector (determining a mirror surface and a light ray direction) through a sun angle and a heat collector position; discretizing the mirror surface: splitting the surface of the judged heliostat into fine grid points (numerical area calculation); light intersection detection: for each grid point, emitting light along the reverse direction of the sun, and judging whether the light intersects with a neighbor mirror (determining a shadow point); calculating efficiency: counting the proportion of shadow grid points, and obtaining the shadow efficiency by using '1-shadow area / total area'. Wherein key vector construction and light intersection detection algorithms are all based on a global coordinate system, a plane equation and a linear equation are constructed by using a geometrical relationship for simultaneous solution, the processes of coordinate transformation and complex equation solution are omitted, the calculation amount and the calculation difficulty are greatly reduced, and meanwhile, good precision is still kept.

The application relates to a shield propulsion unit target thrust calculation method and system based on a plane equation, which comprises the following steps: establishing a space rectangular coordinate system O-XYZ on the installation surface of a shield propulsion system of a shield tunneling machine; determining the angle of a target total thrust point P in a plane XOY; selecting a characteristic propulsion unit in the first quadrant or the second quadrant of the plane XOY; establishing a local coordinate system xOy; setting a target thrust z for each propulsion unit i :z i i =(i=1~n); setting the target thrust of the propulsion unit in a thrust plane, obtaining the values of z0 and k based on the plane equation of the thrust plane, and then obtaining the target thrust of each propulsion unit according to z i =(i=1~n); setting the target thrust of the propulsion unit in a thrust plane, obtaining the values of z0 and k based on the plane equation of the thrust plane, and then obtaining the target thrust of each propulsion unit according to z i The application makes the target thrust of each propulsion unit of the propulsion system meet the condition of being in the same plane, minimizes the difference of the target thrust of each propulsion unit, and solves the problem that the single segment is significantly different in ring surface stress during shield propulsion, thereby ensuring the safety of the segment structure.​

The invention provides a spectral confocal probe pose calibration method and device based on plane constraint, and belongs to the technical field of precision measurement and instruments.The method comprises the steps that firstly, a contact type measuring head is used for measuring at least three non-coplanar plane standard parts, and through coordinate transformation and fitting, the three non-coplanar plane standard parts are obtained; accurately establishing an equation of each standard plane under a machine coordinate system; then, a spectrum confocal probe is used for measuring the same plane piece, obtained measuring point coordinates and distance values are simultaneous with a known plane equation, and a linear overdetermined equation set about probe pose parameters (including an optical axis direction vector and a spatial position vector) is constructed; and finally, solving the equation set through a least square method to obtain accurate pose parameters. According to the method, a nonlinear problem is converted into linear solution, iterative calculation is avoided, and the calibration efficiency and precision are remarkably improved. And meanwhile, measuring points are allowed to be uniformly distributed by utilizing plane constraint, so that the ill-conditioned property of an equation set is effectively reduced, and the robustness of the calibration process is enhanced.

The application discloses a kind of indentation test method and system suitable for complex curved surface parts, it is related to the technical field of material mechanical property test, the method comprises: confirming initial space coordinate system;The surface of the part to be tested is scanned by three-dimensional profilometer, three-dimensional topography data is obtained, curved surface equation is obtained, and tangent plane equation at target measuring point on the part to be tested is calculated;Confirm the angle between the plane intersection line of tangent plane and the initial space coordinate system and horizontal plane, and according to the angle and the preset interval between the telescopic rod, two telescopic rods are calculated and controlled to move;The center point coordinate of spherical hinge moving assembly, the projection point coordinate of vertical projection on the plane where the positioning table is located is calculated to calculate the coordinate of the center of positioning table, and the coordinate difference between projection point coordinate and the center coordinate is calculated to carry out indentation test to the target measuring point, the application can quickly, accurately and non-destructively carry out indentation test to complex curved surface parts.