79 results about "Quadrilateral meshes" patented technology

The invention discloses a curved surface quadrilateral dominant grid generation method, device and equipment for an aircraft and a storage medium, and relates to the technical field of computational fluid mechanics, and the method comprises the steps: creating a surface unstructured grid based on surface grid generation parameters of a CAD file of the aircraft, carrying out the conformal mapping of the surface unstructured grid to a parameter domain plane, and calculating the vertex compression ratio of each grid vertex; selecting the current starting point with the minimum compression ratio and the maximum to-be-compared vertex in the adjacency list, and determining the current to-be-processed vertex with the minimum compression ratio in the adjacent vertexes and the advancing direction; determining to-be-processed discrete points according to the current compression ratio and the coordinate information to generate a current isoline, if the current compression ratio does not exceed a threshold value, iteratively updating the current starting point, and skipping to the step of determining the current to-be-processed vertex again; the discrete points are projected to the outer-layer isolines according to the isoline sequence, and the curved-surface quadrilateral dominant grid is generated based on the distance proportion between each discrete point and the projection point, so that the generation efficiency of the curved-surface quadrilateral grid is improved.

Some implementations relate to methods, systems, and computer-readable media for providing mesh retopology for improved animation of three-dimensional avatar heads. The system receives a three-dimensional mesh that is a representation of an avatar head; defines local coordinate frames relative to geometric features of the mesh; utilizes a machine learning model to predict frame fields based on these features; blends the predicted frame fields to calculate unified directional constraints for each mesh face element; and applies quad meshing techniques to extract a quad mesh representation of the avatar head.

The invention provides a comprehensive scene map path planning method based on an improved A * algorithm, and the method comprises the steps: 1, carrying out environment modeling for a comprehensive scene map: segmenting a two-dimensional plane scene into more than two square grids, and carrying out the assignment of a single grid in a binarization manner to represent the occupation condition of the grids; constructing a protection area formed by a single-layer grid around the obstacle, and filling the protection area into gray; step 2, planning a path by adopting an improved A * algorithm: step 2-1, establishing an improved bidirectional search strategy; step 2-2, establishing a heuristic function with a barrier linear density weight; step 2-3, adopting a variable neighborhood node expansion mode to complete node expansion; and step 2-4, carrying out path secondary optimization. According to the method, the planning efficiency and the path performability in a complex environment are remarkably improved, and an effective solution is provided for navigation systems in the fields of service robots, intelligent warehousing and the like.

The invention discloses a geometric model quadrilateral mesh generation method and system based on GPU parallelism, and belongs to the technical field of computer graphics. The method comprises the following steps: for a geometric model formed by a plurality of surfaces, obtaining parameterized coordinates of surface patches in parallel by a GPU thread, and performing spatial transformation on the parameterized coordinates by establishing a bounding box of the surface patches to obtain a surface patch splicing result; generating an original triangular mesh model based on a patch splicing result, and processing triangular units in the original triangular mesh model in parallel by the GPU thread to obtain a triangular mesh after cavity filtering and network geometric information of the triangular mesh; the GPU thread solves the network topology structure of the triangular mesh in parallel; the GPU thread performs parallel solution of the frame field based on the network geometric information and the network topology information of the triangular mesh; and generating a quadrilateral grid structure of the geometric model in combination with the frame field. According to the method, the grid structure generation efficiency is improved by improving the calculation performance of the curved surface frame field.

The utility model discloses a silicon capacitor electrode structure and a silicon capacitor, which can further improve the capacitance of a capacitor in a limited space by nesting, combining and arranging a plurality of groups of element arrays distributed in a quadrilateral grid mode more reasonably and precisely, so that the capacitor can store more charges.

The present application provides a valve stent, a method for processing a valve stent, and an artificial valve. The valve stent is formed by cutting a metal tube and has a cut state and an expanded state. The valve stent comprises a plurality of grid cell structure units distributed in a circumferential direction of the valve stent and extending in an axial direction of the valve stent. Each grid cell structure unit comprises a plurality of quadrilateral grid cells, and the plurality of quadrilateral grid cells comprise at least one end grid cell proximal to the heart, at least one middle supporting grid cell and at least one end grid cell distal to the heart that are sequentially arranged from a first axial end to a second axial end in the axial direction of the valve stent. Each quadrilateral grid cell comprises four stent rods sequentially connected end to end. Each stent rod comprises a straight rod section and a connecting section. In the cut state, the straight rod sections of two stent rods, opposite to each other in the circumferential direction of the valve stent, of each quadrilateral grid cell gradually diverge from each other from the middle to the end of the quadrilateral grid cell in the axial direction to form an included angle, wherein the included angle of the middle supporting grid cell is less than or equal to 12 degrees.

The invention provides a quadrilateral surface re-topology method based on frame field prediction and electronic equipment. The quadrilateral surface re-topology method based on frame field prediction comprises the following steps: inputting a triangular mesh model into a frame field neural network model, and carrying out direction regression and amplitude diffusion taking the direction as the condition to obtain a corresponding frame field; performing deformation based on the frame field to obtain a deformed grid model; performing isotropic quadrilateral re-mesh division on the deformed mesh model to obtain an initial quadrilateral mesh model; and performing inverse deformation on the initial quadrilateral mesh model to obtain a quadrilateral mesh model corresponding to the triangular mesh model. Through the steps of frame field inference, deformation, isotropic quadrilateral grid re-division and inverse deformation, the quality of the finally generated quadrilateral grid is ensured, so that the purpose of improving the quality of the quadrilateral grid is achieved.

The invention discloses a variable grid method grid automatic division method and device based on vector field guidance. The method comprises the following steps: extracting boundary feature points according to geometric features of an input model boundary so as to construct a feature polygon of a model, and dispersing the feature polygon into a triangular mesh model; constructing a vector field based on a Laplacian operator by using the triangular mesh model; starting from the geometric center of the model, setting an initial quadrilateral grid as an initial paving layer, paving the quadrilateral grid outwards layer by layer, and if the paving layer exceeds the boundary of the model, stopping paving; when each layer of quadrilateral grid deforms, uniform transition is achieved through a size transition template; and finally, generating a boundary quadrilateral mesh of the model by adopting a mapping method, mapping discrete points on the boundary of the feature polygon back to the boundary of the input model, and outputting a generated quadrilateral mesh model. According to the method, full-automatic generation of the quadrilateral mesh can be realized, and the method is particularly suitable for mesh generation in finite element simulation pretreatment.

A method including identifying a first vertex as a vertex to be compressed, identifying a plurality of neighboring vertices as compressed vertices, predicting a position of a second vertex, the second vertex being proximate to one of the plurality of neighboring vertices, predicting a position of a third vertex, the third vertex being proximate to the first vertex, generating a correction variable based on the position of the second vertex and a position of the one of the plurality of neighboring vertices, and determining a position of the first vertex based on the position of the third vertex and the correction variable.

The embodiment of the invention provides a mesh generation method for an additive manufacturing slice type multilayer structure. The mesh generation method can solve the technical problem that the mesh generation capacity is poor in the prior art. The method includes dividing a surface grid on a first surface and converting a second surface into a point cloud result. And matching the grid nodes and the surface nodes according to process constraints to obtain surface node pairs. In this way, not only the geometrical shape is considered, but also the additive manufacturing layering process is considered. And according to the surface node pairs, based on the quadrilateral grids, dividing layered finite element units mainly comprising hexahedrons, that is, generating volume grids through the surface grids. According to the method, the stability of various spatial curved surfaces is ensured while rapid grid division is realized, and a grid division algorithm which is high in automation degree, good in stability and good in grid quality is realized. The additive manufacturing slice type multilayer structure is subjected to grid division, the material direction and the layering direction are accurately appointed, and the efficiency and accuracy of simulation calculation of the additive manufacturing slice type multilayer structure are improved.

The invention discloses a wing quadrilateral unit structure finite element model automatic construction method and device, equipment and a medium, and relates to the technical field of aerospace, and the method comprises the steps: determining third coordinate data of a wing middle section based on a target control parameter, first coordinate data of a wing root section and second coordinate data of a wing tip section; based on the first coordinate data, the second coordinate data and the third coordinate data, constructing an airfoil geometric parameterized model by utilizing a preset interpolation method, generating target grid control points and target grid control edges corresponding to the wing root section, the wing tip section and the wing middle section respectively, and determining a first grid control edge connecting the wing root section and the wing middle section, the second grid control edge is connected with the wing middle section and the wing tip section; and determining a wing quadrilateral unit structure finite element model file based on the first quadrilateral mesh of the skin, the second quadrilateral mesh of the wing rib and the third quadrilateral mesh of the wing spar. And a high-fidelity structural finite element model is efficiently constructed.

A computer-implemented method and apparatus for generating a quadrilateral grid from an image with an alpha channel. The method includes receiving an image with an alpha channel depicting a shape mapped onto a 3D surface, vectorizing the shape to create a vector path, determining corners by calculating a centroid and identifying the points, correcting a winding order to ensure a clockwise orientation, constructing a quadrilateral grid by setting sub-paths based on detected corners, resampling the sub-paths to match specified rows and columns, performing weighted interpolation across the grid using inverse square distance weighting, and outputting the generated quadrilateral grid for display on a computer device. The apparatus comprises a processor configured to execute these steps, including vectorizing the shape, determining corners, correcting the winding order, constructing and resampling the grid, performing weighted interpolation, and subdividing the 3D mesh for flexible manipulation and extrapolation.

The invention provides a communication system operation and maintenance management method and system applying data analysis, and relates to the technical field of data processing.The method comprises the steps that 1, original data streams of equipment operation data and service data are collected in real time, the original data streams are divided according to a preset time window, and the divided original data streams are obtained; mapping the multi-dimensional data in each window into a point cloud data set in a high-dimensional space; 2, based on the point cloud data set, spatial distribution characteristics are extracted through principal component analysis, and a virtual reference plane representing the state is constructed; and step 3, delimiting an initial quadrilateral grid on the virtual reference plane, and performing adaptive segmentation on the initial grid according to the density gradient of the point cloud data set to form heterogeneous sub-regions. According to the invention, real-time accurate early warning of communication system abnormity, rapid fault positioning and predictive maintenance based on trend analysis are realized, and the intelligent level of operation and maintenance management and the reliability of the system are effectively improved.

The embodiment of the invention discloses a multilateral hole filling method based on a generalized non-uniform rational B spline, and the scheme can comprise the following steps: for a multi-pipe mixed connection problem, firstly, fitting a boundary curve by using a uniform rational B spline curve, for example, in a three-pipe mixed connection problem, the boundary curve is a boundary curve of a pipe curved surface and a constructed connection curved surface, and the boundary curve is a boundary curve of a pipe curved surface and a constructed connection curved surface; then constructing a quadrilateral grid as a control grid according to the fitted curve, and generating an initial GNURBS curved surface; and finally, a control point of the GNURBS curved surface is adjusted through energy optimization, so that a smooth filling curved surface meeting normal constraint and curvature constraint is obtained, for example, in the multi-pipe mixed connection problem, the filling curved surface is a mixed connection curved surface for connecting the boundaries of a plurality of pipes.

The present invention discloses a method for generating a full quadrilateral mesh based on a predefined pattern, which specifically relates to the technical field of mesh generation. The specific steps include cleaning a geometric model, setting a predefined pattern for mesh generation according to the cleaned geometric model, defining mesh generation rules, meshing according to the geometric model and the predefined pattern, generating a full quadrilateral mesh based on an overlapping mesh technology, collaboratively scheduling the generation of the full quadrilateral mesh using a distributed architecture platform, optimizing the full quadrilateral mesh using a post-processing technology, performing a quality check on the generated full quadrilateral mesh, evaluating the generation efficiency of the full quadrilateral mesh based on the results of the full quadrilateral mesh quality check and the calculation accuracy in the mesh generation process, and proposing a mesh quality control strategy based on the evaluation results, thereby effectively solving the contradiction between data consistency and processing speed when processing large-scale complex geometric models.

This invention provides a quadrilateral retopology method and electronic device based on frame field prediction. The quadrilateral retopology method based on frame field prediction includes: inputting a triangular mesh model into a frame field neural network model for direction regression and amplitude diffusion conditioned on direction to obtain the corresponding frame field; deforming the frame field to obtain a deformed mesh model; isotropically re-meshing the deformed mesh model to obtain an initial quadrilateral mesh model; and inversely deforming the initial quadrilateral mesh model to obtain a quadrilateral mesh model corresponding to the triangular mesh model. Through the steps of frame field inference, deformation, isotropic quadrilateral re-meshing, and inverse deformation, the quality of the final generated quadrilateral mesh is guaranteed, thereby achieving the goal of improving the quality of the quadrilateral mesh.

The invention discloses a method for creating a long-distance closed mesh surface model, electronic equipment and a storage medium, and the method comprises the steps: obtaining the position of a reference line in a three-dimensional space based on a route design result of linear engineering; analyzing the cross section graph, and constructing cross section component data; establishing a constraint relation of points in the cross section graph based on the reference point, and configuring a label for each constraint; generating an initial stake number list according to a preset segment interval, and dynamically inserting encryption points based on the curve type and combining the encryption points into the initial stake number list to form a final stake number list; mapping corresponding points in the cross section to a three-dimensional space according to the relative coordinates and the plane unit normal vector, and generating a cross section placement list; and on the basis of the cross section placement list and the cross section component data, constructing quadrilateral grids between adjacent cross sections, splicing the quadrilateral grids to generate transition grid surfaces, and forming a closed grid surface model by combining starting and ending transverse grids. According to the method, the precision and efficiency of long-distance linear engineering three-dimensional modeling are remarkably improved.

The invention provides an intelligent grid optimization method and system based on domestic general scientific calculation software, and the method comprises the steps: obtaining and analyzing a grid data file, and obtaining the connection relation information of nodes and units in a grid; converting the grid into a graph structure based on the connection relation information, and inputting the graph structure into a grid smoothing model for optimization to obtain a high-quality grid; the grid smoothing model is obtained by training based on a grid data set in advance; the grid data set is obtained by constructing a geometric shape and randomly adjusting grid points in advance; determining that the grid smoothing model is successfully trained after the loss function is converged; the loss function is obtained by calculating the side length and angle of each grid unit in the grid data set. According to the method, the unsupervised loss function oriented to structured grid smoothing is designed, the unsupervised grid smoothing model oriented to the large-scale structured quadrilateral grid is constructed and trained, nodes of different degrees are smoothed, the method is not influenced by a data input sequence, and the optimization efficiency is improved while the grid optimization quality is improved.

The intelligent generation method for the pure quadrilateral partition based on the diffusion model comprises the following steps: S1, constructing a global integer linear programming model containing a plurality of objective functions, and generating a quadrilateral grid with symmetric and aligned singular points by minimizing the objective functions; s2, obtaining a two-dimensional profile diagram of the CAD model according to the open source three-dimensional CAD model data set ABC; generating a triangular mesh model according to the two-dimensional contour map; s3, boundary fairing processing is carried out on the triangular mesh model, and hole digging and random segmentation are carried out in the triangular mesh model; s4, generating a symbol distance field according to the triangular mesh model; extracting pure quadrilateral partitions according to the quadrilateral grids; obtaining a model outer contour image according to the pure quadrilateral partition; s5, constructing a pure quadrilateral partition to generate a diffusion model; and training a pure quadrilateral partition by using the symbol distance field and the model outer contour image to generate a diffusion model. According to the method, the quick generation of the pure quadrilateral partition is realized, and meanwhile, the training time of the diffusion network model is greatly shortened.

The application discloses a sum and difference beam optimization method of a cover array antenna, and comprises the following steps: creating an array antenna model and a cover array antenna model; performing quadrilateral mesh division on the models respectively; based on the corresponding quadrilateral mesh division of the models, performing simulation calculation by using a high-order moment method, and extracting corresponding active unit directional diagrams; applying excitation to the antenna units in the models, combining the active unit directional diagrams, calculating the sum and difference beams of the models under different scanning angles, and comparing corresponding performance indexes; and using an improved hybrid differential evolution algorithm to optimize the sum and difference beams of the cover array antenna model which does not meet the index requirements; wherein the improved hybrid differential evolution algorithm performs global and local iterative searches, and adaptively calculates a mutation factor and a crossover factor in the global and local iterative search processes. The application realizes the optimization design of the sum and difference beams of the cover array antenna, and is more in line with engineering application requirements.

A method for providing high-resolution touch sensing on 3D objects A computer-implemented method is disclosed for designing a touch sensing arrangement for a 3D object (B), the method includes (i) performing a quad meshing of the surface of the body, the quad mesh including a plurality of quadrangular areas (Q) having side dimensions matching the mutual spacing between pairs of adjacent transmit electrode lines (T) and between pairs of adjacent receive electrode lines (R) of the touch sensing arrangement, (ii) computing a quad patch layout comprising a plurality of quad patches (P), each including a plurality of adjacent quadrangular areas (Q) of the quad mesh, selectively grouping the quad patches (P) into a plurality of clusters (C) of adjacent patches (P) and packing the clusters (C) into a plurality of cluster sets, each cluster set being associated with a respective touch controller (TC), wherein the transmit electrode lines (T) and the receive electrode lines (R) of the touch sensing arrangement are designed according to a dual edge graph of the quad mesh, and interconnecting conducting paths are established between transmit and receive electrode lines (T, R) of each cluster set and the respective touch controller (TC) through the internal volume of the object (B).

The invention relates to the technical field of futures analysis, in particular to a quadrangular block diagram-based futures analysis method. The method comprises the following steps: S1, data collection; s2, preprocessing the data collected in the step S1; s3, constructing a quadrilateral grid through the data processed in the step S2; s4, filling the quadrilateral grids obtained in the step S3 with the data processed in the step S2 to obtain quadrilateral block graphs; s5, carrying out statistics on transaction data in the quadrilateral block graph obtained in the step S4; and S6, determining the futures trading condition for the quadrilateral block diagram obtained in the step S4 through color change. According to the futures analysis method based on the quadrilateral block diagram provided by the invention, by incorporating dimensions such as the specific position amount and the multi-empty direction of the futures market into thermodynamic diagram analysis, the limitation of traditional futures schematic is overcome, and more comprehensive market microstructure insight is provided for futures traders.

The invention discloses a method for generating a quadrilateral curved surface grid, the quadrilateral curved surface grid can cover the curved surface of a three-dimensional object so as to analyze the three-dimensional object, and the method comprises the following steps: obtaining a curved surface digital geometric model of the three-dimensional object; constraint on grid singular point configuration on the curved surface is received, the singular point configuration comprises at least one designated position and a target price number of the designated position, and the price number represents the number of edges connected with grid vertexes; on the basis of the Riemannian-Rooch theory, a finite-dimensional quadrilateral grid generation space is constructed within the range meeting singular point configuration constraints, and construction comprises calculation of a primary function of a sub-pure function linear space L (D) corresponding to singular point configuration; selecting a specific grid generation parameter combination from the quadrilateral grid generation space; a quadrilateral curved surface grid is generated and output according to the grid generation parameter combination, and singular point distribution of the grid conforms to the received constraint; and the quadrilateral curved surface grid is provided for a finite element analysis or isogeometric analysis solver and is used for carrying out simulation analysis of mechanics, thermotics or fluid dynamics on a three-dimensional object.

The pure quadrilateral partition intelligent generation method based on the diffusion model comprises the following steps: S1, a global integer linear programming model containing a plurality of objective functions is constructed, and a quadrilateral grid which is symmetrical and aligned is generated by minimizing the objective function; S2, a two-dimensional contour graph of a CAD model is obtained according to an open source three-dimensional CAD model data set ABC; a triangular mesh model is generated according to the two-dimensional contour graph; S3, boundary fairing treatment is performed on the triangular mesh model, and hole digging and random segmentation are further performed in the interior; S4, a signed distance field is generated according to the triangular mesh model; a pure quadrilateral partition is extracted according to the quadrilateral grid; and a model outer contour image is obtained according to the pure quadrilateral partition; S5, a pure quadrilateral partition generation diffusion model is constructed; and the pure quadrilateral partition generation diffusion model is trained by using the signed distance field and the model outer contour image. The pure quadrilateral partition is rapidly generated, and the training time of the diffusion network model is greatly shortened.

The subject of the application is a price label sheet used for printing commercial content and dividing and shaping without the need for tools, intended for placement on retail shelves. The price label sheet, in the form of a card divided into regular fields with intersecting score lines, is characterized in that the card (1) is divided into quadrilateral fields (4) by score lines (2) interconnected by dot bridges (3) with a width of 0.1 mm to 0.5 mm, with the dot bridges (3) spaced on the edges of the fields (4) at distances of 1 to 20 mm.

The invention discloses a method for optimizing a quadrilateral mesh, electronic equipment and a storage medium. The method comprises the following steps: extracting an initial singular graph from an original quadrilateral grid of target data; performing sub-network recursive segmentation on the original quadrilateral grid based on the initial singular graph, so that each singular point of the initial singular graph is included in each sub-grid; splicing the sub-grids containing the singular points according to the segmentation information and an inverse segmentation sequence, so that the transverse offset sum of each singular line after the singular points are connected is shortest to obtain a new singular graph; and correcting the original quadrilateral mesh based on the new singular graph to optimize the quadrilateral mesh. By utilizing the scheme of the invention, the singular graph regularity of the grid can be systematically improved, so that the overall quality of the quadrilateral grid is improved, and the optimization complexity is reduced.

The embodiment of the application provides a grid division method for additive manufacturing slice type multilayer structure, which can solve the technical problem of poor grid division capability in the related art. The method comprises the following steps: dividing a surface grid on a first surface, and converting a second surface into a point cloud result. According to process constraints, matching grid nodes and surface nodes to obtain surface node pairs. In this way, not only the geometric shape is considered, but also the additive manufacturing layering process. According to the surface node pairs, based on a quadrilateral grid, layered hexahedron-based finite element units are divided, that is, a volume grid is generated through the surface grid. While achieving rapid grid division, the stability of various spatial surfaces is ensured, and a grid division algorithm with high automation degree, good stability and good grid quality is realized. The grid division is performed on the additive manufacturing slice type multilayer structure, the material direction and the layering direction are accurately specified, and the efficiency and accuracy of simulation calculation of the additive manufacturing slice type multilayer structure are improved.

The present invention discloses a method for judging the quality of anisotropic meshes, comprising the following steps: for a generated quadrilateral mesh or triangular mesh, finding the ideal lengths of its u and v direction vectors in its background mesh, and forming a complete parallelogram by drawing parallel lines, that is, the ideal quadrilateral mesh corresponding to the actual mesh; converting the quadrilateral mesh or triangular mesh respectively so that the converted graphics can represent the anisotropic characteristics of the original mesh and coincide with the center of the ideal quadrilateral, and calculating the overlapping area of ​​the two graphics; judging the degree of similarity between the actual mesh and the ideal mesh based on the overlapping area, and determining the mesh quality. The present invention can more accurately judge the quality of anisotropic meshes by comparing the actual mesh with the ideal mesh in the background mesh. The mesh quality is converted into the area of ​​the overlapping area of ​​the two graphics, and the calculation result is more intuitive and easy to understand, with fewer calculation steps and faster speed.

Embodiments of the present invention provide a method for constructing a grid map, a path planning method, a processor, and a device, belonging to the field of map construction. The method for constructing a grid map includes: obtaining a target area; and constructing a grid map for the target area. The grid map comprises an octagonal grid matrix, wherein two adjacent octagonal grids share a common edge, and four adjacent octagonal grids in two adjacent rows or columns enclose a quadrilateral grid. The present invention can reduce computational complexity.

The application relates to the field of mesh generation, and discloses a mesh generation method and system, the method comprising the following steps: acquiring an initial mesh information file; the initial mesh information comprising quadrilateral mesh and position information between the quadrilateral mesh and upper, lower, left and right nodes; constructing a mesh generation model, the mesh generation model comprising a first long short-term memory network and a deep neural network connected in sequence; inputting the initial mesh information file into the trained mesh generation model, performing semantic information embedding on the initial mesh information file by using the first long short-term memory network, and generating a mesh parameter matrix; and transmitting the mesh parameter matrix to the deep neural network to learn mesh parameter information, and generating a mesh division information file. The application improves the precision and efficiency of mesh generation.