398 results about "Triangular grid" patented technology

The invention relates to a triangular gridding based human image face-lift processing method and belongs to the technical field of computer application. By means of triangulation and feature point extraction technology and related geometric method to process the image, the triangular gridding based human image face-lift processing method includes steps of feature point extraction of human faces, triangular gridding, human face outline curve estimation, feature point adjustment, new triangular grid establishing, new image generation and the like. Considering beauty seeking of people and blank of related technology, the triangular gridding based human image face-lift processing method is an automatic digital image face-lift beautifying method, and can realize face-lift beautifying effect simply and quickly by loading in original source image to be subjected to face lift, so that beauty appreciation of people is sufficiently satisfied without undertaking high cost and risk.

Disclosed is a method for calculating core neutron flux distribution of a small experimental reactor. The method includes steps of 1), determining geometrical and material parameters according to a core structure of the small experimental reactor, and establishing a neutron-transport equation describing movement rules of neutrons in each discrete direction inside a reactor core; 2), preparing corresponding quadrature sets for boundaries unparallel in normal surface vectors and each coordinate axis direction; 3), subjecting the neutron-transport equation to numerical discretion to acquire simultaneous linear algebraic equations of angular neutron flux density by a segment method of approximating unstructured geometry with unstructured grids to establish arbitrary triangular grids; 4), solving the simultaneous linear algebraic equations to acquire the discrete distribution of the angular neutron flux density in the reactor core, and acquiring the discrete distribution of neutron-flux density in the reactor core by the aid of relation of the angular neutron flux density and the neutron-flux density. By the method, the neutron-flux distribution of the small experimental reactor, especially that of an isotope production reactor, a pebble bed reactor and a high-flux reactor in the medical field can be accurately acquired.

The invention relates to a three-dimensional model segmenting device and a three-dimensional model segmenting method. The three-dimensional model segmenting method comprises the following steps: plane detection, which comprises detecting the plane in an input three-dimensional model which is described by a triangular grid; profile chart extraction, which comprises extracting the profile of the three-dimensional model, namely, the profile chart according to the plane detected in the plane detecting step; profile chart separation, which comprises segmenting the profile chart extracted in the profile chart extracting step into a plurality of sub charts; and three-dimensional solid rebuilding, which comprises rebuilding the three-dimensional solid models for each sub chart segmented from the profile chart separating step, wherein each rebuilt three-dimensional solid is expressed by the triangular grid.

In a process for determining when tolerances are exceeded during generation of NC parts programs, the defined CAD geometry is converted into an equivalent grid, preferably a triangular grid. A surface corresponding to the NC parts programs in form of a triangular grid is generated after conversion of the CAD geometry. The parts program takes into consideration the geometric attributes of the milling tool (diameter, shape, etc.). After two triangular grids have been generated from the starting data, i.e. the CAD geometry and the NC parts program, the distance between the two grids can be calculated and visualized.

This invention provides a fast and accurate building and molding method for complex surface products, which is characterized with the steps: (1) collecting data and pre-treating them, (2) creating the initial wave pre-ring, (3) defining saturation point, freedom point, wave-front side, wave-front point , wave-front wings and side angle, to generate grid model of the initial measurement data, (4) calculating arrows of all the node and the offset data coordinates values along arrows to generate the triangular grid unit of data points in offset layer, (5) suturing the boundary of original layer and offset layer, ( 6) outputting STL file, producing the prototype.

The invention discloses a block segmentation method for a triangular grid model. The method comprises the steps of reading the triangular grid model and establishing topological information; calculating a concave-convex signal of a vertex of the triangular grid model and performing global Laplace smooth denoising; calculating standardized concave-convex information to obtain a concave characteristic region of the grid model; calculating normalized concave-convex information and reducing the concave characteristic region; extracting a center line of the reduced concave characteristic region; constructing a closed segmentation line by adopting a sector probe ray algorithm; optimizing the segmentation line by adopting a three-dimensional snake method and performing fitting and smoothing on the segmentation line; and segmenting the triangular grid model by adopting a regional growth method. According to the method, the segmentation line meeting a minimum principle in the triangular grid model is extracted for efficiently and reliably segmenting the model into minimum rule sub-blocks meeting the visual requirements.

The invention provides a soft tissue deformation and cutting simulation method based on position dynamics. The method comprises the following four steps: grid preprocessing: according to an original triangular grid and a tetrahedron grid, and calculating a texture coordinate of each peak, calculating a set of edges in the grid, setting dynamics simulation parameters, and generating an improved tetrahedron grid; the deformation calculation of a soft tissue object: according to the current positions and the stressing situation of the peaks of the grids, calculating the positions of the peaks of the grids at a next moment according to the position dynamics; updating during grid topology change: according to an intersection situation of a cutting plane and grid intersection points, dividing an original tetrahedron, and updating the parameters of a geometric model and a position dynamics model; and visual rendering and touch rendering: displaying the soft tissue object and generating force feedback. The invention can truly simulate a process of cutting soft tissues in a virtual surgery, and exhibits high instantaneity.

The invention relates to a passive location method for an underwater moving node based on Beidou beacons, which comprises the steps that 1, a sea surface beacon node receives a location and navigationsignal broadcast by a Beidou satellite navigation system, updates the position in real time and keep pace with the Beidou clock; three sea surface beacons located at vertexes of a triangular grid combine information such as the position and serial number into location messages and broadcast the location messages to the underwater moving node at the same time according to a time sequence table oftransmitting the location messages; and 2, if the underwater moving node receives the location messages, the position of the underwater moving node at the current moment is calculated by using a filtering algorithm according to the arrival time and message content of the three location messages, and if the underwater moving node does not receive the location messages, the position of the underwater moving node at the current moment can also calculated by using the filtering algorithm. The invention further relates to a system used for implementing the passive location method.

The invention discloses an image splicing method based on grid deformation, relating to the technical field of image splicing. The method includes the following steps of S1 respectively extracting SIFT characteristics of two space adjacent images, and matching the characteristics; S2 performing iterative computation by means of an RANSAC algorithm and screening characteristic point pairs; S3 estimating the global projective matrix and performing global projective transformation; S4 by means of Delaunay triangulation, constructing a dense triangular grid for an overlapping region and constructing a sparse grid for a non-overlapping region; S5 establishing the grid deformation energy function and optimizing the global projective registration; and S6 fusing the images to produce a wide-view-field image. The dense triangular grid represents the overlapping region and the sparse triangular grid represents the non-overlapping region of the image, so that compared with the APAP method, the whole image uses dense and same matrix grids, the algorithm efficiency is greatly improved. Meanwhile, the grid deformation can make full use of the parallel and high-speed operation performance of the CPU, and the splicing speed can be greatly improved.

A calculation method for fast reactor neutron transportation burn-up coupling analysis comprises the steps of 1, dividing a radial structure of a reactor core into a triangular grid, establishing a triangular prism grid, dividing burn-up regions with axial segmentation of a subassembly as a unit, dividing internal cycle of a reactor into a plurality of burn-up steps, and executing the following steps for each burn-up step; 2, calculating a small group of macroscopic cross-sections of each burn-up region, and carrying out neutron transportation calculation by use of a neutron transportation calculation method based on the triangular prism grid; 3, calculating a burn-up matrix of each burn-up region at the beginning of the burn-up step, and solving a burn-up equation by use of a Chebyshev rational approximation method; 4, carrying out neutron transportation calculation on the reactor core according to a nucleon density vector of each burn-up region at the end of the burn-up step; 5, averaging the burn-up matrixes at the beginning and at the end of the burn-up step to obtain an average burn-up matrix of each burn-up region, and carrying out burn-up calculation on each bur-up region again from the beginning of the burn-up step; and 6, repeating steps 4 and 5 until the nucleon density vectors of each burn-up region at the end of the burn-up step which are obtained through two adjacent calculations are converged.

The invention discloses a geological-stratum-structure-based method for generating triangular lattice grids, which is used for a system providing input grids for oil-gas migration and accumulation analog computation. The geological-stratum-structure-based method is characterized by comprising the following steps of: constructing a three-dimensional geological stratum structure model and calculating intersecting lines among stratums based on the geological stratum structure; constructing a triangular grid generation unit for each stratum; cooperatively processing a plurality of units sharing the intersecting lines among the stratums to realize a plurality of lattice grids which continuously transition among stratums; storing the triangular lattice grids by using non-manifold half-side data; and optimizing the local connectivity of a grid vertex point unit by adopting a consistent triangular subdividing method. By using the geological-stratum-structure-based method, the automatic generation of the triangular lattice grids under various geological stratum conditions can be realized and the connectivity of computational grids at stratum junction parts is ensured, so that an attribute value of the oil-gas migration can be used for continuous analog computation on various stratums and furthermore, an effective supplementary means is provided for geological experts to predict the favorable accumulation area of oil gas.

The invention relates to a digital designing and making method of an individual tray without edentulous jaw function pressure. The method includes: making an edentulous jaw preliminary impression; scanning the impression or a model to obtain data 1; scanning alveolar ridges of upper and lower jaws to obtain jaw position relation data 2; registering the data 1 to the data 2; completing undercut filling and buffering on the surfaces of the alveolar ridges of the upper and lower jaws; creating a dentition positioning coordinate system in the data 1; scanning a pair of upper-lower jaw dentition reference gypsum models to acquire data 3; creating a dentition posture coordinate system in the data 3; registering the data 3 to the data 1 through coordinate system registering; using a triangular grid to fill gaps between upper and lower jaw data 1 and the data 3 to acquire STL data of the individual tray; printing upper-lower jaw trays. The method replaces complex steps of conventional manual making, clinical operation steps are simplified, operation difficulty is lowered, and clinical diagnosis and treatment efficiency of edentulous jaw complete denture repair is improved.

The invention discloses a remote sensing satellite multispectral image registration method. The remote sensing satellite multispectral image registration method comprises the following steps that 1, a rough registration image is obtained according to the distance of a multispectral detector; 2, histogram projection is carried out on an image to be registered on the basis of a reference image; 3, the two images are partitioned in blocks, and for each pair of image blocks, angular points of each pair of image blocks are extracted, and in order to realize registration of a near infrared image, the main direction phase coincidence characteristic of each block is extracted, and a positive and negative sub pixel matching point set of each block is obtained on the basis of phase correlation and surface fitting; 4, triangular grid partition is carried out on the reference image and the image to be registered, a transformation coefficient is worked out, and resampling is carried out on the image to be registered to obtain a registered image. Compared with the prior art, the method solves the problem that as the gray difference of features of different reflectivities on different spectral sections is large, registration is difficult, and also effectively solves the problem that large remote sensing images in different areas distort to different extents.

The embodiment of the invention discloses an integrated circuit layout field domain identification and grid subdivision processing method and device. The method comprises the following steps: vertically projecting a plurality of polygons of each layer of integrated circuit layout to the same layer to form a Delaunay triangular grid; combining the polygon information and the layer information of the edges of the polygons which are superposed after projection; aligning the grids to the edges of each polygon, calculating the intersection points of the edges of each polygon, adding the intersection points into polygon vertexes and grid nodes to form a first triangular grid, forming a set by the edges of the polygons by an edge exchange method, taking out the edges of the polygons, exchanging the edges of the polygons, and if the set is a null set, ending the exchange; superposing the layer information of the edges of the polygons into all triangles in the polygons; identifying and collecting triangles and polygonal edges contained in each parallel flat plate field domain according to the layer information of the triangles and polygonal edges; and carrying out grid subdivision processing on triangles in each parallel flat plate field domain. According to the invention, the accuracy and high efficiency of the field domain identification and grid subdivision processing method can be ensured.

The invention discloses an internal fixed steel plate preoperative designing and prefabricating method based on augmented reality. The method comprises the steps: interactively regulating planes by users, indicating symmetry planes of a human body, replacing body data of hurt side with body data of the unhurt side, and conducting simulated reconstruction on fracture parts; delineating and designing a reconstructed steel plate trace on the surface of the reconstructed bone, and generating a triangular grid three-dimensional model of the reconstructed steel plate according to the reconstructed steel plate trace; and overlapping and drawing the generated three-dimensional steel plate model on a video image collected in real time, controlling the posture of the three-dimensional model of the steel plate by using an augmented reality optical marker, regulating the model postures by users, observing the coincidence degree of the real steel plate and a virtual steel plate, thus completing the shaping of the steel plate. The method saves the operation time, shortens the treatment courses, reduces the occurrence of complications and improves the cure rate.

The invention discloses a grid free-form surface toroidal cutter path planning method based on improved Butterfly subdivision. The method comprises the steps of toroidal cutter surface modeling and triangular grid free-form surface modeling. Besides, the cutter surface of a cutter contact point (CC point) and a workpiece surface are geometrically analyzed with combination of the geometrical features of the toroidal cutter. The minimum front inclination angle of the cutter is calculated according to the principle of cutting cutter interference so as to obtain the maximum width of a cutting path, based on which subdivision is performed on the triangular grid surface by adopting the improved Butterfly subdivision method so that the line space of the cutter path is enabled to meet the width requirement of the cutting path. Planning of the spiral cutter path cutter contact point (CC point) is performed line by line along the boundary of the triangular grid with a surface contour curve acting as an initial cutter path so that the position of a cutter center (CL point) is finally solved according to the toroidal cutter geometrical model. The method is applied to high-speed machining so that continuity of the formed cutter path can be enhanced, cutter load fluctuation can be reduced, and cutting stability can be enhanced and the service life of the cutter can be prolonged under the premise of guaranteeing the cutting quality.

Provided is an itinerary working area boundary extraction method based on an aggregation degree and Delaunay triangular reconstruction. The method comprises the steps of defining relevancy of two data points, and conducting equidistant compression on the data points based on an accelerated optimization algorithm of equidistant compression; conducting refined extraction on an area-of-interest boundary. The method specifically comprises the first step of preprocessing the data points; the second step of solving a Delaunay triangular net M for a point set S; the third step of utilizing an alpha-shaped algorithm to solve an edge list of an concave envelope of the point set S. In the coarse extraction stage, the dense distribution character of cruise working points is fully made use of, a concept of aggregation degree calculation is put forward, the equidistant compression algorithm is applied, and the speed of automatic location of a cruise area is effectively increased. In the refined extraction stage, an alpha-shape concave envelope edge solving algorithm based on statistical average information is applied, an unreasonable triangle obtained by Delaunary triangulation is automatically recognized and deleted, it is guaranteed that the method has strong adaptation to different triangular grids, and the accuracy degree of edge extraction is greatly increased.

The invention discloses a three-dimensional surface layer model construction method based on a triangular grid, which comprises the following steps: measuring surface layer survey points in an area so as to directly or indirectly obtain geographic position information and a surface layer model parameter of each surface layer survey point; acquiring the geographic position information of all shot detection points in the area; carrying out triangulation on a two-dimensional point set formed by the geographic position information of the surface layer survey points, so as to obtain a Delaunay triangular grid; finding the triangle where each shot detection point is arranged, and using the surface layer survey points in the positions of three vertices of the triangle as control points to calculate the surface layer model parameter Vp of each shot detection point based on an area-weighted interpolation method, as a result, a three-dimensional surface layer model in the area is obtained.

The invention discloses a robot spray workpiece surface modeling method. The method includes the steps of performing triangular grid partitioning on a workpiece surface, setting a maximum normal vector threshold, connecting triangular faces into small flat patches according to a triangular face connecting method, creating a flat patch adjacency graph, and merging all the small flat patches to a plurality of new large flat patches according to a flat patch adjacency graph merging algorithm. The method is applicable to surface modeling of various complicated sprayed workpieces, particularly applicable to surface modeling of workpieces large in curvature change and fast in calculation, so that preparations are made for follow-up spraying robot route planning and trajectory optimization so as to meet requirements on working of a spraying robot, and working efficiency of the spraying robot and quality of products can be improved.

The present invention discloses a terrain modeling and grid generation method and device. The method comprises the steps of: converting rule grid terrain elevation data to a form of X, Y and Z three-dimensional coordinates, performing triangular grid division, achieving consistence of a bottom-layer plane grid topological structure and generating multiple layers of triangular prism grids with suitable lengths of stretch. The technical problems are solved that a method for extraction of point coordinates from contour lines is employed to perform terrain modeling and grid generation, the generated grids are sparse and cannot realistically restore terrain details and if the number of extracted data points is added to caused slow speed of node searching and positioning and the computation amount is large in the prior art.

The invention relates to an implementation method for a photonic crystal biochemical sensor array capable of realizing parallel perception. A photonic crystal biochemical sensor array is implemented on the same two-dimensional photonic crystal flat module for the first time. A two-dimensional photonic crystal-based flat structure is designed, and due to the design of a combination of resonant cavities with different resonant frequencies, high-efficiency coupling between various resonant cavities and a photonic crystal waveguide can be implemented, and the photonic crystal biochemical sensor array is designed. The array has a basic structure of a triangular grid photonic crystal flat structure based on an air hole, and mainly comprises a line defect photonic crystal waveguide (W1 waveguide) and a plurality of resonant cavities with different resonant frequencies. In the scheme, five resonant cavities with different resonant frequencies are adopted, which are named H0-cavity-1, H0-cavity-2, H0-cavity-3, H0-cavity-4 and H0-cavity-5 respectively. Because high-efficiency coupling between the various resonant cavities and the photonic crystal waveguide can be implemented, a light field can be locally distributed in respective area through the various resonant cavities, and the capacity of parallelly sensing small-volume analyzed object is provided.

The invention provides a method for carrying out finite element parametric modeling on a triangular grid stiffener cylinder structure. According to the invention, the method for carrying out parametric modeling on the triangular grid stiffener cylinder structure is established and is realized by using MSC (Mobile Switching Center).PCL (Pinter Control Language) programming, modeling parameters comprise seven parameters of height H of a cylinder, external radius R, covering thickness t, circumferential grid number n, rib crossing angle theta, rib height h and width w, a finite element analysis model can be quickly established by any combination of the seven parameters on the premise that reasonable combination is met, and the time for carrying out modeling on a daily microcomputer is about five seconds through actual measurements. The method provided by the invention has the advantages of high modeling automation level, quick speed, good element mass and high analysis accuracy; high-accuracy and fast-optimization analysis on the triangular grid stiffener cylinder structure can be realized by matching optimization design software such as Isight.